mmcdara

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9 years, 63 days

MaplePrimes Activity


These are replies submitted by mmcdara

It works well without any corrections with Maple 2015.2.

A tip: try to use the package "Statistics" instead of "Student:-Statistics".
Then change 

B := BetaRandomVariable(61, 2)

by

B := RandomVariable(BetaDistribution(61, 2))

 

@9009134 thanks

Tracking the site you mention (Andrews' paper) I found this one where Mathematica has been used to plot the streamline  potential-flow-around-a-torus-laplace-equation-in-toroidal-coordinates.
Are they the kind of plots you woulf like to obtain with Maple?

 

@nm 

Much simpler than the solution I've obtained, great.

I agree with @rlopez , the figure you present has nothing to do with the laminar flow of a viscous fluid around a cylinder.
See here for instance petitRe.pdf

Where do your formulas come from?
 

@Mac Dude 

I agree, I guess "0.78 kg CO2/ kg" must be interpreted as "0.78 Kg of CO2 per kilogram of <something>".
So its seems to be more a question of text formatting than a question of units.
Maybe something like this (with Maple 2015 ; could be inproved in latter versions by using neutral operators %* and %/ instead of `per kg`)

0.78*Unit('kg')*`CO__2`*`per kg`


 

@Carl Love @acer

Your two proposals are not strictly equivalentfor the depend on the structure of the data lists.
Acer's seems to be a little bit mode generic.

Here LL represents carl's list of the lists of "y" values and LLL the list of the lists of "(x,y)" couples.
 

restart

with(plots):

LL := [ [$1..3], [$2..4] ];
LLL := map(ListTools:-Enumerate, LL);
 

[[1, 2, 3], [2, 3, 4]]

 

[[[1, 1], [2, 2], [3, 3]], [[1, 2], [2, 3], [3, 4]]]

(1)

pLL  := plot(map(ListTools:-Enumerate, LL)):
pLLL := plot(map(ListTools:-Enumerate, LLL)):
DocumentTools:-Tabulate([ pLL, pLLL ]);

pLL  := display(map(plots:-listplot,LL)):
pLLL := display(map(plots:-listplot,LLL)):
DocumentTools:-Tabulate([ pLL, pLLL ]);

 


 

Download DataList.mw

Your model is a  linear model under a proper reparameterization.

Note that, even if it  is a quite common way to linearize a model, the method can lead to numerical instabilities if the auxiliary variables of the reparameterization are of very different magnitudes.

More of this, even in its original rational form the model depends only on 4 parameters (you can divide both its numerator and its denominator without changing the results).
 

restart;
with(Statistics):
X:=Vector([0,0.001,0.002,0.003,0.004,0.005,0.006,0.007,0.008,0.009,0.01,0.012]):
Y:=Vector([1.103,1.057,1.016,0.978,0.94,0.91,0.88,0.85,0.826,0.8,0.778,0.735]):
# Transform the original Model into an Alternate one named AltModel

Model := y-(-a*t+b)/(-d+e*t+f*t^3)=0;
normal(Model);
AltModel := numer(lhs(Model)); # everywhere denom(lhs(Model)) <> 0
                 
# Rename z__p each product (t^p)*y
# Then the model is a linear model of the form y=A + B*t + C*z__1 + D*z__3
# It can be found using LinearFit once the vectors corresponding to z__1 and z__3 have been constructed

ZModel := [1, t, z__1, z__3]:
res := Statistics:-LinearFit([1, t, z__1, z__3], <X | X*~Y | (X^~3)*~Y | Y >, [t, z__1, z__3])

# Express this resultl in native variables t and y

RES := y = eval(res, [z__1=y*t, z__3=y*t^3])

# Rebuild the model under rational form

isolate(RES, y);
Fn := rhs(%):

plots:-display(plot(X,Y,style=point,color=red,symbolsize=12), plot(Fn,t=X[1]..X[-1],color=blue), labels=["X","Y"]);

Download LinearFit.mw

@acer 

Excellent!

Just a question, why does 
solve(convert~(Or(x::A,x::C, x::B),relation)); 
return x while
solve(x<+infinity)
returns 
RealRange(-infinity, Open(infinity)) ?

@Ivi 

The ides is the following :

  • Set u(t)=0.007-f(t)
     
  • Then the equation writes diff(u(t),t) = beta*C1*u(t)^2 + C2*u(t)^3 where C1 and C2 are constants and beta is a short for A(t) = (1.75*exp(0.06*t)-0.75*exp(-200*t)) and, at this point, beta is considered as a constant.
     
  • Set v(t)=1/u(t)
     
  • Derive the EDO in v(t)
     
  • Set the initial condition under the form v(T)=K, where T >=0 and K an appropriate constant.
    For instance, if T=0, then K=1 / 0.007 given the two transformations f(t) --> u(t) --> v(t).
     
  • Solve it exactly (not numerically) : this is possible because (with beta constant) the ode is of a classical form.
     
  • Let "sol" this exact solution (it depends on t, beta, T, K)
     
  • Now proceed this way to construct the global solution over [0, tau] where tau > 0:
    • vsol := [ [0, 1/0.007]]
    • for theta from 0 to tau by delta_theta do
          beta := A(theta);
          T      := theta;
          K      := vsol[-1][2]; # value of v at the last generated point
          compute sol(beta, T, K, t=theta+step)  ; # means "advance" the solution from theta to theta+step
         add the point [theta, sol(beta, T, K, t=theta+step)] to vsol
      end do
       
  • look vsol : the values of v are complex but the first ones have a very small imaginary part one can think is due to numerical precision.
    Keep only the points [t, v(t)] for wich Im(v(t)) is small.
     
  • Plot the result. It appears to be very close to the result obtained with rkf45 for instance.
    This prooves the singularity diagnosed by dsolve[numeric] is not some numeric artefact, but a consequence of the LambertW function that the exact "local" (meaning "with constant beta") solution contains.

 


 

restart:

with(plots):

Digits := 15:

Q := 0.00002:
A := t -> ( (1.75*exp(0.06*t)-0.75*exp(-200*t))*(0.007-f(t))^3 / 0.007 - (0.007-f(t))^2 ) / Q;
q:= diff(f(t),t) + A(t)=0;
ic1 := f(0)=0;

proc (t) options operator, arrow; ((1.75*exp(0.6e-1*t)-.75*exp(-200*t))*(0.7e-2-f(t))^3/0.7e-2-(0.7e-2-f(t))^2)/Q end proc

 

diff(f(t), t)+7142857.14285715*(1.75*exp(0.6e-1*t)-.75*exp(-200*t))*(0.7e-2-f(t))^3-50000.0000000000*(0.7e-2-f(t))^2 = 0

 

f(0) = 0

(1)

# the term 1.75*exp(0.6e-1*t)-.75*exp(-200*t) is replaced by beta
# the initial contitions will be of the form function(T)=K (T >= 0)

q1  := diff(f(t),t) + '( beta*(0.007-f(t))^3 / 0.007 - (0.007-f(t))^2 ) / Q' = 0;
q2  := isolate( eval(q1, f(t)=0.007-u(t)), diff(u(t), t) );
q3 := algsubs(u(t)=1/v(t), q2):
q3 := isolate(q3, diff(v(t),t));

infolevel[dsolve] := 4:

dsol1 := dsolve({q3, v(T)=K}) assuming beta > 1, K > 0, T >= 0

diff(f(t), t)+(142.857142857143*beta*(0.7e-2-f(t))^3-(0.7e-2-f(t))^2)/Q = 0

 

diff(u(t), t) = 7142857.14285715*beta*u(t)^3-50000.0000000000*u(t)^2

 

diff(v(t), t) = (-7142857.14285715*beta+50000.0000000000*v(t))/v(t)

 

Methods for first order ODEs:
--- Trying classification methods ---
trying a quadrature
trying 1st order linear
trying Bernoulli

trying separable
<- separable successful

 

v(t) = (142857142857143/1000000000000)*beta*(LambertW((1/142857142857143)*exp((50000000000000000/142857142857143)*(-T+(1/50000)*K+(142857142857143/50000000000000000)*beta*ln(-142857142857143*beta+1000000000000*K))/beta)*exp(-1)*exp((50000000000000000/142857142857143)*t/beta)/beta)+1)

(2)

sol := evalf(eval(v(t), dsol1));

142.857142857143*beta*(LambertW(0.257515608820009e-14*exp(350.000000000000*(-1.*T+0.200000000000000e-4*K+0.285714285714286e-2*beta*ln(-142857142857143.*beta+1000000000000.*K))/beta)*exp(350.000000000000*t/beta)/beta)+1.)

(3)

# Stepwise construction of the solution.
# The "piece n" is defined over an interval ]n*step, (n+1)*step] with initial
# condition v[n](n*step) = v[n-1](n*step)

vsol := [[0, 1/0.007]]:
fsol := [[0, 0]]:
step := 0.0001:
for theta from 0 to 0.01 by step do
  b    := 1.75*exp(0.6e-1*theta)-.75*exp(-200*theta);
  k    := vsol[-1][2]:
  vsol := [ vsol[], [theta, eval(sol, [T=theta, K=k, beta=b, t=theta+step])] ];
  fsol := [ fsol[], [theta, 0.007-1/vsol[-1][2]] ];
end do:

fsol: # uncomment and observe ending points are of the form [t, a+I*b]

# for b in [t, a+I*b] close to 0 : take the real part a
#                                  else stop
#

map(s -> if abs(Im(s[2])) < 10^(-10) then Re~(s) end if, fsol);

plot(%);

[[0, 0], [0, 0.1e-16], [0.1e-3, -0.370849130031e-5], [0.2e-3, -0.1120226877261e-4], [0.3e-3, -0.2258113074144e-4], [0.4e-3, -0.3796983759807e-4], [0.5e-3, -0.5752056126953e-4], [0.6e-3, -0.8141591576507e-4], [0.7e-3, -0.10987268495655e-3], [0.8e-3, -0.14314639725918e-3], [0.9e-3, -0.18153694072471e-3], [0.10e-2, -0.22539547009471e-3], [0.11e-2, -0.27513293508619e-3], [0.12e-2, -0.33123066451667e-3], [0.13e-2, -0.39425358535368e-3], [0.14e-2, -0.46486685655670e-3], [0.15e-2, -0.54385698041070e-3], [0.16e-2, -0.63215885845426e-3], [0.17e-2, -0.73089084662796e-3], [0.18e-2, -0.84140073285687e-3], [0.19e-2, -0.96532686932517e-3], [0.20e-2, -0.110468070661100e-2], [0.21e-2, -0.126196015191373e-2], [0.22e-2, -0.144030830972355e-2], [0.23e-2, -0.164374072032465e-2], [0.24e-2, -0.187747895258251e-2], [0.25e-2, -0.214845479253160e-2], [0.26e-2, -0.246609863272737e-2], [0.27e-2, -0.284362293588760e-2], [0.28e-2, -0.33002155003400e-2], [0.29e-2, -0.38650176427321e-2], [0.30e-2, -0.45849032410184e-2], [0.31e-2, -0.55412583949793e-2], [0.32e-2, -0.68913812514323e-2], [0.33e-2, -0.89929801407614e-2], [0.34e-2, -0.129256044844755e-1], [0.35e-2, -0.251750392360810e-1]]

 

 

 


 

Download modest_contribution_2.mw

 

@Ivi 
I agree with Preben, 
This is what I used to do when Preben was working on his side. I had "identified" the coefficient befor diff(f(t),t) as the "critical" one.

 

restart:

with(plots):

Digits := 20:

Q := 0.00002:
A := t -> ( (1.75*exp(0.06*t)-0.75*exp(-200*t))*(0.007-f(t))^3 / 0.007 - (0.007-f(t))^2 ) / Q;
q:= diff(f(t),t) + A(t)=0;
ic1 := f(0)=0;
dsol1 := dsolve({q, ic1}, numeric);

proc (t) options operator, arrow; ((1.75*exp(0.6e-1*t)-.75*exp(-200*t))*(0.7e-2-f(t))^3/0.7e-2-(0.7e-2-f(t))^2)/Q end proc

 

diff(f(t), t)+7142857.1428571428570*(1.75*exp(0.6e-1*t)-.75*exp(-200*t))*(0.7e-2-f(t))^3-50000.000000000000000*(0.7e-2-f(t))^2 = 0

 

f(0) = 0

 

proc (x_rkf45) local _res, _dat, _vars, _solnproc, _xout, _ndsol, _pars, _n, _i; option `Copyright (c) 2000 by Waterloo Maple Inc. All rights reserved.`; if 1 < nargs then error "invalid input: too many arguments" end if; _EnvDSNumericSaveDigits := Digits; Digits := 20; if _EnvInFsolve = true then _xout := evalf[_EnvDSNumericSaveDigits](x_rkf45) else _xout := evalf(x_rkf45) end if; _dat := Array(1..4, {(1) = proc (_xin) local _xout, _dtbl, _dat, _vmap, _x0, _y0, _val, _dig, _n, _ne, _nd, _nv, _pars, _ini, _par, _i, _j, _k, _src; option `Copyright (c) 2002 by Waterloo Maple Inc. All rights reserved.`; table( [( "complex" ) = false ] ) _xout := _xin; _pars := []; _dtbl := array( 1 .. 4, [( 1 ) = (array( 1 .. 24, [( 1 ) = (datatype = sfloat, order = C_order, storage = rectangular), ( 2 ) = (datatype = sfloat, order = C_order, storage = rectangular), ( 3 ) = ([0, 0, 0, Array(1..0, 1..2, {}, order = C_order)]), ( 4 ) = (Array(1..54, {(1) = 1, (2) = 1, (3) = 0, (4) = 0, (5) = 0, (6) = 0, (7) = 1, (8) = 0, (9) = 0, (10) = 0, (11) = 0, (12) = 0, (13) = 0, (14) = 0, (15) = 0, (16) = 0, (17) = 0, (18) = 21, (19) = 30000, (20) = 0, (21) = 1, (22) = 1, (23) = 4, (24) = 0, (25) = 2, (26) = 20, (27) = 1, (28) = 0, (29) = 1, (30) = 3, (31) = 3, (32) = 0, (33) = 1, (34) = 0, (35) = 0, (36) = 0, (37) = 0, (38) = 0, (39) = 0, (40) = 0, (41) = 0, (42) = 0, (43) = 1, (44) = 0, (45) = 0, (46) = 0, (47) = 0, (48) = 0, (49) = 0, (50) = 50, (51) = 1, (52) = 0, (53) = 0, (54) = 0}, datatype = integer[8])), ( 5 ) = (Array(1..28, {(1) = 0., (2) = 0.1e-5, (3) = 0., (4) = 0.500001e-19, (5) = 0., (6) = 0.22891402602795194723e-2, (7) = 0., (8) = 0.1e-5, (9) = 0., (10) = 0., (11) = 0., (12) = 0., (13) = 1., (14) = 0., (15) = .49999999999999, (16) = 0., (17) = 1., (18) = 1., (19) = 0., (20) = 0., (21) = 1., (22) = 1., (23) = 0., (24) = 0., (25) = 0.1e-14, (26) = 0., (27) = 0., (28) = 0.}, order = C_order)), ( 6 ) = (Array(1..1, {(1) = 0.}, order = C_order)), ( 7 ) = ([Array(1..4, 1..7, {(1, 1) = 0., (1, 2) = 26., (1, 3) = 39., (1, 4) = 96., (1, 5) = 104., (1, 6) = 52., (1, 7) = 104., (2, 1) = 33440., (2, 2) = 0., (2, 3) = 146432., (2, 4) = 142805., (2, 5) = -50787., (2, 6) = 10260., (2, 7) = 282150., (3, 1) = 1045., (3, 2) = 0., (3, 3) = -11264., (3, 4) = -10985., (3, 5) = 7524., (3, 6) = 13680., (3, 7) = 376200., (4, 1) = 1629155., (4, 2) = 0., (4, 3) = 6769664., (4, 4) = 340535., (4, 5) = -101574., (4, 6) = -800280., (4, 7) = 13062500.}, order = C_order), Array(1..6, 1..6, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (1, 6) = 1., (2, 1) = 1., (2, 2) = 0., (2, 3) = 0., (2, 4) = 0., (2, 5) = 0., (2, 6) = 4., (3, 1) = 3., (3, 2) = 9., (3, 3) = 0., (3, 4) = 0., (3, 5) = 0., (3, 6) = 32., (4, 1) = 1932., (4, 2) = -7200., (4, 3) = 7296., (4, 4) = 0., (4, 5) = 0., (4, 6) = 2197., (5, 1) = 8341., (5, 2) = -32832., (5, 3) = 29440., (5, 4) = -845., (5, 5) = 0., (5, 6) = 4104., (6, 1) = -6080., (6, 2) = 41040., (6, 3) = -28352., (6, 4) = 9295., (6, 5) = -5643., (6, 6) = 20520.}, order = C_order), Array(1..6, {(1) = 0., (2) = .386, (3) = .210, (4) = .630, (5) = 1., (6) = 1.}, order = C_order), Array(1..6, {(1) = .25, (2) = -.1043, (3) = .1035, (4) = -0.362e-1, (5) = 0., (6) = 0.}, order = C_order), Array(1..6, 1..5, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (2, 1) = 1.5440000000000000000, (2, 2) = 0., (2, 3) = 0., (2, 4) = 0., (2, 5) = 0., (3, 1) = .94667852808155328615, (3, 2) = .25570116989825811637, (3, 3) = 0., (3, 4) = 0., (3, 5) = 0., (4, 1) = 3.3148251870684885588, (4, 2) = 2.8961240159721231525, (4, 3) = .99864191399778072571, (4, 4) = 0., (4, 5) = 0., (5, 1) = 1.2212245092262748236, (5, 2) = 6.0191344812877529055, (5, 3) = 12.537083329320874572, (5, 4) = -.68788603610589513565, (5, 5) = 0., (6, 1) = 1.2212245092262748236, (6, 2) = 6.0191344812877529055, (6, 3) = 12.537083329320874572, (6, 4) = -.68788603610589513565, (6, 5) = 1.}, order = C_order), Array(1..6, 1..5, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (2, 1) = -5.6688000000000000000, (2, 2) = 0., (2, 3) = 0., (2, 4) = 0., (2, 5) = 0., (3, 1) = -2.4300933568337581851, (3, 2) = -.20635991570891223664, (3, 3) = 0., (3, 4) = 0., (3, 5) = 0., (4, 1) = -.10735290581452621845, (4, 2) = -9.5945622510218943195, (4, 3) = -20.470286148096154811, (4, 4) = 0., (4, 5) = 0., (5, 1) = 7.4964433139686150258, (5, 2) = -10.246804314641218318, (5, 3) = -33.999903528199063499, (5, 4) = 11.708908932061595438, (5, 5) = 0., (6, 1) = 8.0832467959224109291, (6, 2) = -7.9811329880627854783, (6, 3) = -31.521594328743729054, (6, 4) = 16.319305431231361893, (6, 5) = -6.0588182388340537633}, order = C_order), Array(1..3, 1..5, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (2, 1) = 10.126235083446912057, (2, 2) = -7.4879958776076331333, (2, 3) = -34.800918615557411398, (2, 4) = -7.9927717075687273372, (2, 5) = 1.0251377232956206444, (3, 1) = -.67628033928068977703, (3, 2) = 6.0877146516786064462, (3, 3) = 16.430843208924630647, (3, 4) = 24.767225114183651253, (3, 5) = -6.5943891257167816112}, order = C_order)]), ( 9 ) = ([Array(1..1, {(1) = .10000000000000000000}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, 1..1, {(1, 1) = 0.}, order = C_order), Array(1..1, 1..1, {(1, 1) = 0.}, order = C_order), Array(1..1, 1..6, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (1, 6) = 0.}, order = C_order), Array(1..1, {(1) = 0}, datatype = integer[8]), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order)]), ( 8 ) = ([Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), 0, 0]), ( 11 ) = (Array(1..6, 0..1, {(1, 1) = 0., (2, 0) = 0., (2, 1) = 0., (3, 0) = 0., (3, 1) = 0., (4, 0) = 0., (4, 1) = 0., (5, 0) = 0., (5, 1) = 0., (6, 0) = 0., (6, 1) = 0.}, order = C_order)), ( 10 ) = ([proc (N, X, Y, YP) option `[Y[1] = f(t)]`; YP[1] := -7142857.1428571428570*(1.75*exp(0.6e-1*X)-.75*exp(-200*X))*(0.7e-2-Y[1])^3+50000.000000000000000*(0.7e-2-Y[1])^2; 0 end proc, -1, 0, 0, 0, 0, 0, 0]), ( 13 ) = (), ( 12 ) = (), ( 15 ) = ("rkf45"), ( 14 ) = ([0, 0]), ( 18 ) = ([]), ( 19 ) = (0), ( 16 ) = ([0, 0, 0, []]), ( 17 ) = ([proc (N, X, Y, YP) option `[Y[1] = f(t)]`; YP[1] := -7142857.1428571428570*(1.75*exp(0.6e-1*X)-.75*exp(-200*X))*(0.7e-2-Y[1])^3+50000.000000000000000*(0.7e-2-Y[1])^2; 0 end proc, -1, 0, 0, 0, 0, 0, 0]), ( 22 ) = (0), ( 23 ) = (0), ( 20 ) = ([]), ( 21 ) = (0), ( 24 ) = (0)  ] ))  ] ); _y0 := Array(0..1, {(1) = 0.}); _vmap := array( 1 .. 1, [( 1 ) = (1)  ] ); _x0 := _dtbl[1][5][5]; _n := _dtbl[1][4][1]; _ne := _dtbl[1][4][3]; _nd := _dtbl[1][4][4]; _nv := _dtbl[1][4][16]; if not type(_xout, 'numeric') then if member(_xout, ["start", "left", "right"]) then if _Env_smart_dsolve_numeric = true or _dtbl[1][4][10] = 1 then if _xout = "left" then if type(_dtbl[2], 'table') then return _dtbl[2][5][1] end if elif _xout = "right" then if type(_dtbl[3], 'table') then return _dtbl[3][5][1] end if end if end if; return _dtbl[1][5][5] elif _xout = "method" then return _dtbl[1][15] elif _xout = "storage" then return evalb(_dtbl[1][4][10] = 1) elif _xout = "leftdata" then if not type(_dtbl[2], 'array') then return NULL else return eval(_dtbl[2]) end if elif _xout = "rightdata" then if not type(_dtbl[3], 'array') then return NULL else return eval(_dtbl[3]) end if elif _xout = "enginedata" then return eval(_dtbl[1]) elif _xout = "enginereset" then _dtbl[2] := evaln(_dtbl[2]); _dtbl[3] := evaln(_dtbl[3]); return NULL elif _xout = "initial" then return procname(_y0[0]) elif _xout = "laxtol" then return _dtbl[`if`(member(_dtbl[4], {2, 3}), _dtbl[4], 1)][5][18] elif _xout = "numfun" then return `if`(member(_dtbl[4], {2, 3}), _dtbl[_dtbl[4]][4][18], 0) elif _xout = "parameters" then return [seq(_y0[_n+_i], _i = 1 .. nops(_pars))] elif _xout = "initial_and_parameters" then return procname(_y0[0]), [seq(_y0[_n+_i], _i = 1 .. nops(_pars))] elif _xout = "last" then if _dtbl[4] <> 2 and _dtbl[4] <> 3 or _x0-_dtbl[_dtbl[4]][5][1] = 0. then error "no information is available on last computed point" else _xout := _dtbl[_dtbl[4]][5][1] end if elif _xout = "function" then if _dtbl[1][4][33]-2. = 0 then return eval(_dtbl[1][10], 1) else return eval(_dtbl[1][10][1], 1) end if elif _xout = "map" then return copy(_vmap) elif type(_xin, `=`) and type(rhs(_xin), 'list') and member(lhs(_xin), {"initial", "parameters", "initial_and_parameters"}) then _ini, _par := [], []; if lhs(_xin) = "initial" then _ini := rhs(_xin) elif lhs(_xin) = "parameters" then _par := rhs(_xin) elif select(type, rhs(_xin), `=`) <> [] then _par, _ini := selectremove(type, rhs(_xin), `=`) elif nops(rhs(_xin)) < nops(_pars)+1 then error "insufficient data for specification of initial and parameters" else _par := rhs(_xin)[-nops(_pars) .. -1]; _ini := rhs(_xin)[1 .. -nops(_pars)-1] end if; _xout := lhs(_xout); if _par <> [] then `dsolve/numeric/process_parameters`(_n, _pars, _par, _y0) end if; if _ini <> [] then `dsolve/numeric/process_initial`(_n-_ne, _ini, _y0, _pars, _vmap) end if; `dsolve/numeric/SC/reinitialize`(_dtbl, _y0, _n, procname, _pars); if _Env_smart_dsolve_numeric = true and type(_y0[0], 'numeric') and _dtbl[1][4][10] <> 1 then procname("right") := _y0[0]; procname("left") := _y0[0] end if; if _xout = "initial" then return [_y0[0], seq(_y0[_vmap[_i]], _i = 1 .. _n-_ne)] elif _xout = "parameters" then return [seq(_y0[_n+_i], _i = 1 .. nops(_pars))] else return [_y0[0], seq(_y0[_vmap[_i]], _i = 1 .. _n-_ne)], [seq(_y0[_n+_i], _i = 1 .. nops(_pars))] end if elif _xin = "eventstop" then if _nv = 0 then error "this solution has no events" end if; _i := _dtbl[4]; if _i <> 2 and _i <> 3 then return 0 end if; if _dtbl[_i][4][10] = 1 and assigned(_dtbl[5-_i]) and _dtbl[_i][4][9] < 100 and 100 <= _dtbl[5-_i][4][9] then _i := 5-_i; _dtbl[4] := _i; _j := round(_dtbl[_i][4][17]); return round(_dtbl[_i][3][1][_j, 1]) elif 100 <= _dtbl[_i][4][9] then _j := round(_dtbl[_i][4][17]); return round(_dtbl[_i][3][1][_j, 1]) else return 0 end if elif _xin = "eventstatus" then if _nv = 0 then error "this solution has no events" end if; _i := [selectremove(proc (a) options operator, arrow; _dtbl[1][3][1][a, 7] = 1 end proc, {seq(_j, _j = 1 .. round(_dtbl[1][3][1][_nv+1, 1]))})]; return ':-enabled' = _i[1], ':-disabled' = _i[2] elif _xin = "eventclear" then if _nv = 0 then error "this solution has no events" end if; _i := _dtbl[4]; if _i <> 2 and _i <> 3 then error "no events to clear" end if; if _dtbl[_i][4][10] = 1 and assigned(_dtbl[5-_i]) and _dtbl[_i][4][9] < 100 and 100 < _dtbl[5-_i][4][9] then _dtbl[4] := 5-_i; _i := 5-_i end if; if _dtbl[_i][4][9] < 100 then error "no events to clear" elif _nv < _dtbl[_i][4][9]-100 then error "event error condition cannot be cleared" else _j := _dtbl[_i][4][9]-100; if irem(round(_dtbl[_i][3][1][_j, 4]), 2) = 1 then error "retriggerable events cannot be cleared" end if; _j := round(_dtbl[_i][3][1][_j, 1]); for _k to _nv do if _dtbl[_i][3][1][_k, 1] = _j then if _dtbl[_i][3][1][_k, 2] = 3 then error "range events cannot be cleared" end if; _dtbl[_i][3][1][_k, 8] := _dtbl[_i][3][1][_nv+1, 8] end if end do; _dtbl[_i][4][17] := 0; _dtbl[_i][4][9] := 0; if _dtbl[1][4][10] = 1 then if _i = 2 then try procname(procname("left")) catch:  end try else try procname(procname("right")) catch:  end try end if end if end if; return  elif type(_xin, `=`) and member(lhs(_xin), {"eventdisable", "eventenable"}) then if _nv = 0 then error "this solution has no events" end if; if type(rhs(_xin), {('list')('posint'), ('set')('posint')}) then _i := {op(rhs(_xin))} elif type(rhs(_xin), 'posint') then _i := {rhs(_xin)} else error "event identifiers must be integers in the range 1..%1", round(_dtbl[1][3][1][_nv+1, 1]) end if; if select(proc (a) options operator, arrow; _nv < a end proc, _i) <> {} then error "event identifiers must be integers in the range 1..%1", round(_dtbl[1][3][1][_nv+1, 1]) end if; _k := {}; for _j to _nv do if member(round(_dtbl[1][3][1][_j, 1]), _i) then _k := `union`(_k, {_j}) end if end do; _i := _k; if lhs(_xin) = "eventdisable" then _dtbl[4] := 0; _j := [evalb(assigned(_dtbl[2]) and member(_dtbl[2][4][17], _i)), evalb(assigned(_dtbl[3]) and member(_dtbl[3][4][17], _i))]; for _k in _i do _dtbl[1][3][1][_k, 7] := 0; if assigned(_dtbl[2]) then _dtbl[2][3][1][_k, 7] := 0 end if; if assigned(_dtbl[3]) then _dtbl[3][3][1][_k, 7] := 0 end if end do; if _j[1] then for _k to _nv+1 do if _k <= _nv and not type(_dtbl[2][3][4][_k, 1], 'undefined') then userinfo(3, {'events', 'eventreset'}, `reinit #2, event code `, _k, ` to defined init `, _dtbl[2][3][4][_k, 1]); _dtbl[2][3][1][_k, 8] := _dtbl[2][3][4][_k, 1] elif _dtbl[2][3][1][_k, 2] = 0 and irem(iquo(round(_dtbl[2][3][1][_k, 4]), 32), 2) = 1 then userinfo(3, {'events', 'eventreset'}, `reinit #2, event code `, _k, ` to rate hysteresis init `, _dtbl[2][5][24]); _dtbl[2][3][1][_k, 8] := _dtbl[2][5][24] elif _dtbl[2][3][1][_k, 2] = 0 and irem(iquo(round(_dtbl[2][3][1][_k, 4]), 2), 2) = 0 then userinfo(3, {'events', 'eventreset'}, `reinit #2, event code `, _k, ` to initial init `, _x0); _dtbl[2][3][1][_k, 8] := _x0 else userinfo(3, {'events', 'eventreset'}, `reinit #2, event code `, _k, ` to fireinitial init `, _x0-1); _dtbl[2][3][1][_k, 8] := _x0-1 end if end do; _dtbl[2][4][17] := 0; _dtbl[2][4][9] := 0; if _dtbl[1][4][10] = 1 then procname(procname("left")) end if end if; if _j[2] then for _k to _nv+1 do if _k <= _nv and not type(_dtbl[3][3][4][_k, 2], 'undefined') then userinfo(3, {'events', 'eventreset'}, `reinit #3, event code `, _k, ` to defined init `, _dtbl[3][3][4][_k, 2]); _dtbl[3][3][1][_k, 8] := _dtbl[3][3][4][_k, 2] elif _dtbl[3][3][1][_k, 2] = 0 and irem(iquo(round(_dtbl[3][3][1][_k, 4]), 32), 2) = 1 then userinfo(3, {'events', 'eventreset'}, `reinit #3, event code `, _k, ` to rate hysteresis init `, _dtbl[3][5][24]); _dtbl[3][3][1][_k, 8] := _dtbl[3][5][24] elif _dtbl[3][3][1][_k, 2] = 0 and irem(iquo(round(_dtbl[3][3][1][_k, 4]), 2), 2) = 0 then userinfo(3, {'events', 'eventreset'}, `reinit #3, event code `, _k, ` to initial init `, _x0); _dtbl[3][3][1][_k, 8] := _x0 else userinfo(3, {'events', 'eventreset'}, `reinit #3, event code `, _k, ` to fireinitial init `, _x0+1); _dtbl[3][3][1][_k, 8] := _x0+1 end if end do; _dtbl[3][4][17] := 0; _dtbl[3][4][9] := 0; if _dtbl[1][4][10] = 1 then procname(procname("right")) end if end if else for _k in _i do _dtbl[1][3][1][_k, 7] := 1 end do; _dtbl[2] := evaln(_dtbl[2]); _dtbl[3] := evaln(_dtbl[3]); _dtbl[4] := 0; if _dtbl[1][4][10] = 1 then if _x0 <= procname("right") then try procname(procname("right")) catch:  end try end if; if procname("left") <= _x0 then try procname(procname("left")) catch:  end try end if end if end if; return  elif type(_xin, `=`) and lhs(_xin) = "eventfired" then if not type(rhs(_xin), 'list') then error "'eventfired' must be specified as a list" end if; if _nv = 0 then error "this solution has no events" end if; if _dtbl[4] <> 2 and _dtbl[4] <> 3 then error "'direction' must be set prior to calling/setting 'eventfired'" end if; _i := _dtbl[4]; _val := NULL; if not assigned(_EnvEventRetriggerWarned) then _EnvEventRetriggerWarned := false end if; for _k in rhs(_xin) do if type(_k, 'integer') then _src := _k elif type(_k, 'integer' = 'anything') and type(evalf(rhs(_k)), 'numeric') then _k := lhs(_k) = evalf[max(Digits, 18)](rhs(_k)); _src := lhs(_k) else error "'eventfired' entry is not valid: %1", _k end if; if _src < 1 or round(_dtbl[1][3][1][_nv+1, 1]) < _src then error "event identifiers must be integers in the range 1..%1", round(_dtbl[1][3][1][_nv+1, 1]) end if; _src := {seq(`if`(_dtbl[1][3][1][_j, 1]-_src = 0., _j, NULL), _j = 1 .. _nv)}; if nops(_src) <> 1 then error "'eventfired' can only be set/queried for root-finding events and time/interval events" end if; _src := _src[1]; if _dtbl[1][3][1][_src, 2] <> 0. and _dtbl[1][3][1][_src, 2]-2. <> 0. then error "'eventfired' can only be set/queried for root-finding events and time/interval events" elif irem(round(_dtbl[1][3][1][_src, 4]), 2) = 1 then if _EnvEventRetriggerWarned = false then WARNING(`'eventfired' has no effect on events that retrigger`) end if; _EnvEventRetriggerWarned := true end if; if _dtbl[_i][3][1][_src, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_src, 4]), 32), 2) = 1 then _val := _val, undefined elif type(_dtbl[_i][3][4][_src, _i-1], 'undefined') or _i = 2 and _dtbl[2][3][1][_src, 8] < _dtbl[2][3][4][_src, 1] or _i = 3 and _dtbl[3][3][4][_src, 2] < _dtbl[3][3][1][_src, 8] then _val := _val, _dtbl[_i][3][1][_src, 8] else _val := _val, _dtbl[_i][3][4][_src, _i-1] end if; if type(_k, `=`) then if _dtbl[_i][3][1][_src, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_src, 4]), 32), 2) = 1 then error "cannot set event code for a rate hysteresis event" end if; userinfo(3, {'events', 'eventreset'}, `manual set event code `, _src, ` to value `, rhs(_k)); _dtbl[_i][3][1][_src, 8] := rhs(_k); _dtbl[_i][3][4][_src, _i-1] := rhs(_k) end if end do; return [_val] elif type(_xin, `=`) and lhs(_xin) = "direction" then if not member(rhs(_xin), {-1, 1, ':-left', ':-right'}) then error "'direction' must be specified as either '1' or 'right' (positive) or '-1' or 'left' (negative)" end if; _src := `if`(_dtbl[4] = 2, -1, `if`(_dtbl[4] = 3, 1, undefined)); _i := `if`(member(rhs(_xin), {1, ':-right'}), 3, 2); _dtbl[4] := _i; _dtbl[_i] := `dsolve/numeric/SC/IVPdcopy`(_dtbl[1], `if`(assigned(_dtbl[_i]), _dtbl[_i], NULL)); if 0 < _nv then for _j to _nv+1 do if _j <= _nv and not type(_dtbl[_i][3][4][_j, _i-1], 'undefined') then userinfo(3, {'events', 'eventreset'}, `reinit #4, event code `, _j, ` to defined init `, _dtbl[_i][3][4][_j, _i-1]); _dtbl[_i][3][1][_j, 8] := _dtbl[_i][3][4][_j, _i-1] elif _dtbl[_i][3][1][_j, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_j, 4]), 32), 2) = 1 then userinfo(3, {'events', 'eventreset'}, `reinit #4, event code `, _j, ` to rate hysteresis init `, _dtbl[_i][5][24]); _dtbl[_i][3][1][_j, 8] := _dtbl[_i][5][24] elif _dtbl[_i][3][1][_j, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_j, 4]), 2), 2) = 0 then userinfo(3, {'events', 'eventreset'}, `reinit #4, event code `, _j, ` to initial init `, _x0); _dtbl[_i][3][1][_j, 8] := _x0 else userinfo(3, {'events', 'eventreset'}, `reinit #4, event code `, _j, ` to fireinitial init `, _x0-2*_i+5.0); _dtbl[_i][3][1][_j, 8] := _x0-2*_i+5.0 end if end do end if; return _src elif _xin = "eventcount" then if _dtbl[1][3][1] = 0 or _dtbl[4] <> 2 and _dtbl[4] <> 3 then return 0 else return round(_dtbl[_dtbl[4]][3][1][_nv+1, 12]) end if else return "procname" end if end if; if _xout = _x0 then return [_x0, seq(evalf(_dtbl[1][6][_vmap[_i]]), _i = 1 .. _n-_ne)] end if; _i := `if`(_x0 <= _xout, 3, 2); if _xin = "last" and 0 < _dtbl[_i][4][9] and _dtbl[_i][4][9] < 100 then _dat := eval(_dtbl[_i], 2); _j := _dat[4][20]; return [_dat[11][_j, 0], seq(_dat[11][_j, _vmap[_i]], _i = 1 .. _n-_ne-_nd), seq(_dat[8][1][_vmap[_i]], _i = _n-_ne-_nd+1 .. _n-_ne)] end if; if not type(_dtbl[_i], 'array') then _dtbl[_i] := `dsolve/numeric/SC/IVPdcopy`(_dtbl[1], `if`(assigned(_dtbl[_i]), _dtbl[_i], NULL)); if 0 < _nv then for _j to _nv+1 do if _j <= _nv and not type(_dtbl[_i][3][4][_j, _i-1], 'undefined') then userinfo(3, {'events', 'eventreset'}, `reinit #5, event code `, _j, ` to defined init `, _dtbl[_i][3][4][_j, _i-1]); _dtbl[_i][3][1][_j, 8] := _dtbl[_i][3][4][_j, _i-1] elif _dtbl[_i][3][1][_j, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_j, 4]), 32), 2) = 1 then userinfo(3, {'events', 'eventreset'}, `reinit #5, event code `, _j, ` to rate hysteresis init `, _dtbl[_i][5][24]); _dtbl[_i][3][1][_j, 8] := _dtbl[_i][5][24] elif _dtbl[_i][3][1][_j, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_j, 4]), 2), 2) = 0 then userinfo(3, {'events', 'eventreset'}, `reinit #5, event code `, _j, ` to initial init `, _x0); _dtbl[_i][3][1][_j, 8] := _x0 else userinfo(3, {'events', 'eventreset'}, `reinit #5, event code `, _j, ` to fireinitial init `, _x0-2*_i+5.0); _dtbl[_i][3][1][_j, 8] := _x0-2*_i+5.0 end if end do end if end if; if _xin <> "last" then if 0 < 0 then if `dsolve/numeric/checkglobals`(op(_dtbl[1][14]), _pars, _n, _y0) then `dsolve/numeric/SC/reinitialize`(_dtbl, _y0, _n, procname, _pars, _i) end if end if; if _dtbl[1][4][7] = 0 then error "parameters must be initialized before solution can be computed" end if end if; _dat := eval(_dtbl[_i], 2); _dtbl[4] := _i; try _src := `dsolve/numeric/SC/IVPrun`(_dat, _xout) catch: userinfo(2, `dsolve/debug`, print(`Exception in solnproc:`, [lastexception][2 .. -1])); error  end try; if _src = 0 and 100 < _dat[4][9] then _val := _dat[3][1][_nv+1, 8] else _val := _dat[11][_dat[4][20], 0] end if; if _src <> 0 or _dat[4][9] <= 0 then _dtbl[1][5][1] := _xout else _dtbl[1][5][1] := _val end if; if _i = 3 and _val < _xout then Rounding := -infinity; if _dat[4][9] = 1 then error "cannot evaluate the solution further right of %1, probably a singularity", evalf[8](_val) elif _dat[4][9] = 2 then error "cannot evaluate the solution further right of %1, maxfun limit exceeded (see ?dsolve,maxfun for details)", evalf[8](_val) elif _dat[4][9] = 3 then if _dat[4][25] = 3 then error "cannot evaluate the solution past the initial point, problem may be initially singular or improperly set up" else error "cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up" end if elif _dat[4][9] = 4 then error "cannot evaluate the solution further right of %1, accuracy goal cannot be achieved with specified 'minstep'", evalf[8](_val) elif _dat[4][9] = 5 then error "cannot evaluate the solution further right of %1, too many step failures, tolerances may be too loose for problem", evalf[8](_val) elif _dat[4][9] = 6 then error "cannot evaluate the solution further right of %1, cannot downgrade delay storage for problems with delay derivative order > 1, try increasing delaypts", evalf[8](_val) elif _dat[4][9] = 10 then error "cannot evaluate the solution further right of %1, interrupt requested", evalf[8](_val) elif 100 < _dat[4][9] then if _dat[4][9]-100 = _nv+1 then error "constraint projection failure on event at t=%1", evalf[8](_val) elif _dat[4][9]-100 = _nv+2 then error "index-1 and derivative evaluation failure on event at t=%1", evalf[8](_val) elif _dat[4][9]-100 = _nv+3 then error "maximum number of event iterations reached (%1) at t=%2", round(_dat[3][1][_nv+1, 3]), evalf[8](_val) else if _Env_dsolve_nowarnstop <> true then `dsolve/numeric/warning`(StringTools:-FormatMessage("cannot evaluate the solution further right of %1, event #%2 triggered a halt", evalf[8](_val), round(_dat[3][1][_dat[4][9]-100, 1]))) end if; Rounding := 'nearest'; _xout := _val end if else error "cannot evaluate the solution further right of %1", evalf[8](_val) end if elif _i = 2 and _xout < _val then Rounding := infinity; if _dat[4][9] = 1 then error "cannot evaluate the solution further left of %1, probably a singularity", evalf[8](_val) elif _dat[4][9] = 2 then error "cannot evaluate the solution further left of %1, maxfun limit exceeded (see ?dsolve,maxfun for details)", evalf[8](_val) elif _dat[4][9] = 3 then if _dat[4][25] = 3 then error "cannot evaluate the solution past the initial point, problem may be initially singular or improperly set up" else error "cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up" end if elif _dat[4][9] = 4 then error "cannot evaluate the solution further left of %1, accuracy goal cannot be achieved with specified 'minstep'", evalf[8](_val) elif _dat[4][9] = 5 then error "cannot evaluate the solution further left of %1, too many step failures, tolerances may be too loose for problem", evalf[8](_val) elif _dat[4][9] = 6 then error "cannot evaluate the solution further left of %1, cannot downgrade delay storage for problems with delay derivative order > 1, try increasing delaypts", evalf[8](_val) elif _dat[4][9] = 10 then error "cannot evaluate the solution further right of %1, interrupt requested", evalf[8](_val) elif 100 < _dat[4][9] then if _dat[4][9]-100 = _nv+1 then error "constraint projection failure on event at t=%1", evalf[8](_val) elif _dat[4][9]-100 = _nv+2 then error "index-1 and derivative evaluation failure on event at t=%1", evalf[8](_val) elif _dat[4][9]-100 = _nv+3 then error "maximum number of event iterations reached (%1) at t=%2", round(_dat[3][1][_nv+1, 3]), evalf[8](_val) else if _Env_dsolve_nowarnstop <> true then `dsolve/numeric/warning`(StringTools:-FormatMessage("cannot evaluate the solution further left of %1, event #%2 triggered a halt", evalf[8](_val), round(_dat[3][1][_dat[4][9]-100, 1]))) end if; Rounding := 'nearest'; _xout := _val end if else error "cannot evaluate the solution further left of %1", evalf[8](_val) end if end if; if _EnvInFsolve = true then _dig := _dat[4][26]; _dat[4][26] := _EnvDSNumericSaveDigits; _Env_dsolve_SC_native := true; if _dat[4][25] = 1 then _i := 1; _dat[4][25] := 2 else _i := _dat[4][25] end if; _val := `dsolve/numeric/SC/IVPval`(_dat, _xout, _src); _dat[4][25] := _i; _dat[4][26] := _dig; [_xout, seq(_val[_vmap[_i]], _i = 1 .. _n-_ne)] else Digits := _dat[4][26]; _val := `dsolve/numeric/SC/IVPval`(eval(_dat, 2), _xout, _src); [_xout, seq(_val[_vmap[_i]], _i = 1 .. _n-_ne)] end if end proc, (2) = Array(0..0, {}), (3) = [t, f(t)], (4) = []}); _vars := _dat[3]; _pars := map(rhs, _dat[4]); _n := nops(_vars)-1; _solnproc := _dat[1]; if not type(_xout, 'numeric') then if member(x_rkf45, ["start", 'start', "method", 'method', "left", 'left', "right", 'right', "leftdata", "rightdata", "enginedata", "eventstop", 'eventstop', "eventclear", 'eventclear', "eventstatus", 'eventstatus', "eventcount", 'eventcount', "laxtol", 'laxtol', "numfun", 'numfun', NULL]) then _res := _solnproc(convert(x_rkf45, 'string')); if 1 < nops([_res]) then return _res elif type(_res, 'array') then return eval(_res, 1) elif _res <> "procname" then return _res end if elif member(x_rkf45, ["last", 'last', "initial", 'initial', "parameters", 'parameters', "initial_and_parameters", 'initial_and_parameters', NULL]) then _xout := convert(x_rkf45, 'string'); _res := _solnproc(_xout); if _xout = "parameters" then return [seq(_pars[_i] = _res[_i], _i = 1 .. nops(_pars))] elif _xout = "initial_and_parameters" then return [seq(_vars[_i+1] = [_res][1][_i+1], _i = 0 .. _n), seq(_pars[_i] = [_res][2][_i], _i = 1 .. nops(_pars))] else return [seq(_vars[_i+1] = _res[_i+1], _i = 0 .. _n)] end if elif type(_xout, `=`) and member(lhs(_xout), ["initial", 'initial', "parameters", 'parameters', "initial_and_parameters", 'initial_and_parameters', NULL]) then _xout := convert(lhs(x_rkf45), 'string') = rhs(x_rkf45); if type(rhs(_xout), 'list') then _res := _solnproc(_xout) else error "initial and/or parameter values must be specified in a list" end if; if lhs(_xout) = "initial" then return [seq(_vars[_i+1] = _res[_i+1], _i = 0 .. _n)] elif lhs(_xout) = "parameters" then return [seq(_pars[_i] = _res[_i], _i = 1 .. nops(_pars))] else return [seq(_vars[_i+1] = [_res][1][_i+1], _i = 0 .. _n), seq(_pars[_i] = [_res][2][_i], _i = 1 .. nops(_pars))] end if elif type(_xout, `=`) and member(lhs(_xout), ["eventdisable", 'eventdisable', "eventenable", 'eventenable', "eventfired", 'eventfired', "direction", 'direction', NULL]) then return _solnproc(convert(lhs(x_rkf45), 'string') = rhs(x_rkf45)) elif _xout = "solnprocedure" then return eval(_solnproc) elif _xout = "sysvars" then return _vars end if; if procname <> unknown then return ('procname')(x_rkf45) else _ndsol; _ndsol := pointto(_dat[2][0]); return ('_ndsol')(x_rkf45) end if end if; try _res := _solnproc(_xout); [seq(_vars[_i+1] = _res[_i+1], _i = 0 .. _n)] catch: error  end try end proc

(1)

eval(A(t), dsol1(0.0036042680));
eval(A(t), dsol1(0.0036042690));
eval(A(t), dsol1(0.00360426902));
eval(A(t), dsol1(0.00360426903));

3399221997.0435994167

 

680668752355.22175825

 

3503338519945.9771532

 

3786976381295498.9088

(2)

dsol1(0.00360426903)

[t = 0.360426903e-2, f(t) = -725.97506467670869699]

(3)

# estimation of f(0.00360426903+dt)
next_f := eval(f(t), dsol1(0.00360426903)) - eval(A(t), dsol1(0.00360426903)) *dt

-725.97506467670869699-3786976381295498.9088*dt

(4)

Q := 0.00002 * 100:
A := t -> ( (1.75*exp(0.06*t)-0.75*exp(-200*t))*(0.007-f(t))^3 / 0.007 - (0.007-f(t))^2 ) / Q;
q:= diff(f(t),t) + A(t)=0;
ic1 := f(0)=0;
dsol1 := dsolve({q, ic1}, numeric);
odeplot(dsol1, [t, f(t)], t=0..0.15);

proc (t) options operator, arrow; ((1.75*exp(0.6e-1*t)-.75*exp(-200*t))*(0.7e-2-f(t))^3/0.7e-2-(0.7e-2-f(t))^2)/Q end proc

 

diff(f(t), t)+71428.571428571428570*(1.75*exp(0.6e-1*t)-.75*exp(-200*t))*(0.7e-2-f(t))^3-500.00000000000000000*(0.7e-2-f(t))^2 = 0

 

f(0) = 0

 

proc (x_rkf45) local _res, _dat, _vars, _solnproc, _xout, _ndsol, _pars, _n, _i; option `Copyright (c) 2000 by Waterloo Maple Inc. All rights reserved.`; if 1 < nargs then error "invalid input: too many arguments" end if; _EnvDSNumericSaveDigits := Digits; Digits := 20; if _EnvInFsolve = true then _xout := evalf[_EnvDSNumericSaveDigits](x_rkf45) else _xout := evalf(x_rkf45) end if; _dat := Array(1..4, {(1) = proc (_xin) local _xout, _dtbl, _dat, _vmap, _x0, _y0, _val, _dig, _n, _ne, _nd, _nv, _pars, _ini, _par, _i, _j, _k, _src; option `Copyright (c) 2002 by Waterloo Maple Inc. All rights reserved.`; table( [( "complex" ) = false ] ) _xout := _xin; _pars := []; _dtbl := array( 1 .. 4, [( 1 ) = (array( 1 .. 24, [( 1 ) = (datatype = sfloat, order = C_order, storage = rectangular), ( 2 ) = (datatype = sfloat, order = C_order, storage = rectangular), ( 3 ) = ([0, 0, 0, Array(1..0, 1..2, {}, order = C_order)]), ( 4 ) = (Array(1..54, {(1) = 1, (2) = 1, (3) = 0, (4) = 0, (5) = 0, (6) = 0, (7) = 1, (8) = 0, (9) = 0, (10) = 0, (11) = 0, (12) = 0, (13) = 0, (14) = 0, (15) = 0, (16) = 0, (17) = 0, (18) = 47, (19) = 30000, (20) = 0, (21) = 1, (22) = 1, (23) = 4, (24) = 0, (25) = 2, (26) = 20, (27) = 1, (28) = 0, (29) = 1, (30) = 3, (31) = 3, (32) = 0, (33) = 1, (34) = 0, (35) = 0, (36) = 0, (37) = 0, (38) = 0, (39) = 0, (40) = 0, (41) = 0, (42) = 0, (43) = 1, (44) = 0, (45) = 0, (46) = 0, (47) = 0, (48) = 0, (49) = 0, (50) = 50, (51) = 1, (52) = 0, (53) = 0, (54) = 0}, datatype = integer[8])), ( 5 ) = (Array(1..28, {(1) = 0., (2) = 0.1e-5, (3) = 0., (4) = 0.500001e-19, (5) = 0., (6) = 0.12027917720921017610e-1, (7) = 0., (8) = 0.1e-5, (9) = 0., (10) = 0., (11) = 0., (12) = 0., (13) = 1., (14) = 0., (15) = .49999999999999, (16) = 0., (17) = 1., (18) = 1., (19) = 0., (20) = 0., (21) = 1., (22) = 1., (23) = 0., (24) = 0., (25) = 0.1e-14, (26) = 0., (27) = 0., (28) = 0.}, order = C_order)), ( 6 ) = (Array(1..1, {(1) = 0.}, order = C_order)), ( 7 ) = ([Array(1..4, 1..7, {(1, 1) = 0., (1, 2) = 26., (1, 3) = 39., (1, 4) = 96., (1, 5) = 104., (1, 6) = 52., (1, 7) = 104., (2, 1) = 33440., (2, 2) = 0., (2, 3) = 146432., (2, 4) = 142805., (2, 5) = -50787., (2, 6) = 10260., (2, 7) = 282150., (3, 1) = 1045., (3, 2) = 0., (3, 3) = -11264., (3, 4) = -10985., (3, 5) = 7524., (3, 6) = 13680., (3, 7) = 376200., (4, 1) = 1629155., (4, 2) = 0., (4, 3) = 6769664., (4, 4) = 340535., (4, 5) = -101574., (4, 6) = -800280., (4, 7) = 13062500.}, order = C_order), Array(1..6, 1..6, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (1, 6) = 1., (2, 1) = 1., (2, 2) = 0., (2, 3) = 0., (2, 4) = 0., (2, 5) = 0., (2, 6) = 4., (3, 1) = 3., (3, 2) = 9., (3, 3) = 0., (3, 4) = 0., (3, 5) = 0., (3, 6) = 32., (4, 1) = 1932., (4, 2) = -7200., (4, 3) = 7296., (4, 4) = 0., (4, 5) = 0., (4, 6) = 2197., (5, 1) = 8341., (5, 2) = -32832., (5, 3) = 29440., (5, 4) = -845., (5, 5) = 0., (5, 6) = 4104., (6, 1) = -6080., (6, 2) = 41040., (6, 3) = -28352., (6, 4) = 9295., (6, 5) = -5643., (6, 6) = 20520.}, order = C_order), Array(1..6, {(1) = 0., (2) = .386, (3) = .210, (4) = .630, (5) = 1., (6) = 1.}, order = C_order), Array(1..6, {(1) = .25, (2) = -.1043, (3) = .1035, (4) = -0.362e-1, (5) = 0., (6) = 0.}, order = C_order), Array(1..6, 1..5, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (2, 1) = 1.5440000000000000000, (2, 2) = 0., (2, 3) = 0., (2, 4) = 0., (2, 5) = 0., (3, 1) = .94667852808155328615, (3, 2) = .25570116989825811637, (3, 3) = 0., (3, 4) = 0., (3, 5) = 0., (4, 1) = 3.3148251870684885588, (4, 2) = 2.8961240159721231525, (4, 3) = .99864191399778072571, (4, 4) = 0., (4, 5) = 0., (5, 1) = 1.2212245092262748236, (5, 2) = 6.0191344812877529055, (5, 3) = 12.537083329320874572, (5, 4) = -.68788603610589513565, (5, 5) = 0., (6, 1) = 1.2212245092262748236, (6, 2) = 6.0191344812877529055, (6, 3) = 12.537083329320874572, (6, 4) = -.68788603610589513565, (6, 5) = 1.}, order = C_order), Array(1..6, 1..5, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (2, 1) = -5.6688000000000000000, (2, 2) = 0., (2, 3) = 0., (2, 4) = 0., (2, 5) = 0., (3, 1) = -2.4300933568337581851, (3, 2) = -.20635991570891223664, (3, 3) = 0., (3, 4) = 0., (3, 5) = 0., (4, 1) = -.10735290581452621845, (4, 2) = -9.5945622510218943195, (4, 3) = -20.470286148096154811, (4, 4) = 0., (4, 5) = 0., (5, 1) = 7.4964433139686150258, (5, 2) = -10.246804314641218318, (5, 3) = -33.999903528199063499, (5, 4) = 11.708908932061595438, (5, 5) = 0., (6, 1) = 8.0832467959224109291, (6, 2) = -7.9811329880627854783, (6, 3) = -31.521594328743729054, (6, 4) = 16.319305431231361893, (6, 5) = -6.0588182388340537633}, order = C_order), Array(1..3, 1..5, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (2, 1) = 10.126235083446912057, (2, 2) = -7.4879958776076331333, (2, 3) = -34.800918615557411398, (2, 4) = -7.9927717075687273372, (2, 5) = 1.0251377232956206444, (3, 1) = -.67628033928068977703, (3, 2) = 6.0877146516786064462, (3, 3) = 16.430843208924630647, (3, 4) = 24.767225114183651253, (3, 5) = -6.5943891257167816112}, order = C_order)]), ( 9 ) = ([Array(1..1, {(1) = .10000000000000000000}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, 1..1, {(1, 1) = 0.}, order = C_order), Array(1..1, 1..1, {(1, 1) = 0.}, order = C_order), Array(1..1, 1..6, {(1, 1) = 0., (1, 2) = 0., (1, 3) = 0., (1, 4) = 0., (1, 5) = 0., (1, 6) = 0.}, order = C_order), Array(1..1, {(1) = 0}, datatype = integer[8]), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order)]), ( 8 ) = ([Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), Array(1..1, {(1) = 0.}, order = C_order), 0, 0]), ( 11 ) = (Array(1..6, 0..1, {(1, 1) = 0., (2, 0) = 0., (2, 1) = 0., (3, 0) = 0., (3, 1) = 0., (4, 0) = 0., (4, 1) = 0., (5, 0) = 0., (5, 1) = 0., (6, 0) = 0., (6, 1) = 0.}, order = C_order)), ( 10 ) = ([proc (N, X, Y, YP) option `[Y[1] = f(t)]`; YP[1] := -71428.571428571428570*(1.75*exp(0.6e-1*X)-.75*exp(-200*X))*(0.7e-2-Y[1])^3+500.00000000000000000*(0.7e-2-Y[1])^2; 0 end proc, -1, 0, 0, 0, 0, 0, 0]), ( 13 ) = (), ( 12 ) = (), ( 15 ) = ("rkf45"), ( 14 ) = ([0, 0]), ( 18 ) = ([]), ( 19 ) = (0), ( 16 ) = ([0, 0, 0, []]), ( 17 ) = ([proc (N, X, Y, YP) option `[Y[1] = f(t)]`; YP[1] := -71428.571428571428570*(1.75*exp(0.6e-1*X)-.75*exp(-200*X))*(0.7e-2-Y[1])^3+500.00000000000000000*(0.7e-2-Y[1])^2; 0 end proc, -1, 0, 0, 0, 0, 0, 0]), ( 22 ) = (0), ( 23 ) = (0), ( 20 ) = ([]), ( 21 ) = (0), ( 24 ) = (0)  ] ))  ] ); _y0 := Array(0..1, {(1) = 0.}); _vmap := array( 1 .. 1, [( 1 ) = (1)  ] ); _x0 := _dtbl[1][5][5]; _n := _dtbl[1][4][1]; _ne := _dtbl[1][4][3]; _nd := _dtbl[1][4][4]; _nv := _dtbl[1][4][16]; if not type(_xout, 'numeric') then if member(_xout, ["start", "left", "right"]) then if _Env_smart_dsolve_numeric = true or _dtbl[1][4][10] = 1 then if _xout = "left" then if type(_dtbl[2], 'table') then return _dtbl[2][5][1] end if elif _xout = "right" then if type(_dtbl[3], 'table') then return _dtbl[3][5][1] end if end if end if; return _dtbl[1][5][5] elif _xout = "method" then return _dtbl[1][15] elif _xout = "storage" then return evalb(_dtbl[1][4][10] = 1) elif _xout = "leftdata" then if not type(_dtbl[2], 'array') then return NULL else return eval(_dtbl[2]) end if elif _xout = "rightdata" then if not type(_dtbl[3], 'array') then return NULL else return eval(_dtbl[3]) end if elif _xout = "enginedata" then return eval(_dtbl[1]) elif _xout = "enginereset" then _dtbl[2] := evaln(_dtbl[2]); _dtbl[3] := evaln(_dtbl[3]); return NULL elif _xout = "initial" then return procname(_y0[0]) elif _xout = "laxtol" then return _dtbl[`if`(member(_dtbl[4], {2, 3}), _dtbl[4], 1)][5][18] elif _xout = "numfun" then return `if`(member(_dtbl[4], {2, 3}), _dtbl[_dtbl[4]][4][18], 0) elif _xout = "parameters" then return [seq(_y0[_n+_i], _i = 1 .. nops(_pars))] elif _xout = "initial_and_parameters" then return procname(_y0[0]), [seq(_y0[_n+_i], _i = 1 .. nops(_pars))] elif _xout = "last" then if _dtbl[4] <> 2 and _dtbl[4] <> 3 or _x0-_dtbl[_dtbl[4]][5][1] = 0. then error "no information is available on last computed point" else _xout := _dtbl[_dtbl[4]][5][1] end if elif _xout = "function" then if _dtbl[1][4][33]-2. = 0 then return eval(_dtbl[1][10], 1) else return eval(_dtbl[1][10][1], 1) end if elif _xout = "map" then return copy(_vmap) elif type(_xin, `=`) and type(rhs(_xin), 'list') and member(lhs(_xin), {"initial", "parameters", "initial_and_parameters"}) then _ini, _par := [], []; if lhs(_xin) = "initial" then _ini := rhs(_xin) elif lhs(_xin) = "parameters" then _par := rhs(_xin) elif select(type, rhs(_xin), `=`) <> [] then _par, _ini := selectremove(type, rhs(_xin), `=`) elif nops(rhs(_xin)) < nops(_pars)+1 then error "insufficient data for specification of initial and parameters" else _par := rhs(_xin)[-nops(_pars) .. -1]; _ini := rhs(_xin)[1 .. -nops(_pars)-1] end if; _xout := lhs(_xout); if _par <> [] then `dsolve/numeric/process_parameters`(_n, _pars, _par, _y0) end if; if _ini <> [] then `dsolve/numeric/process_initial`(_n-_ne, _ini, _y0, _pars, _vmap) end if; `dsolve/numeric/SC/reinitialize`(_dtbl, _y0, _n, procname, _pars); if _Env_smart_dsolve_numeric = true and type(_y0[0], 'numeric') and _dtbl[1][4][10] <> 1 then procname("right") := _y0[0]; procname("left") := _y0[0] end if; if _xout = "initial" then return [_y0[0], seq(_y0[_vmap[_i]], _i = 1 .. _n-_ne)] elif _xout = "parameters" then return [seq(_y0[_n+_i], _i = 1 .. nops(_pars))] else return [_y0[0], seq(_y0[_vmap[_i]], _i = 1 .. _n-_ne)], [seq(_y0[_n+_i], _i = 1 .. nops(_pars))] end if elif _xin = "eventstop" then if _nv = 0 then error "this solution has no events" end if; _i := _dtbl[4]; if _i <> 2 and _i <> 3 then return 0 end if; if _dtbl[_i][4][10] = 1 and assigned(_dtbl[5-_i]) and _dtbl[_i][4][9] < 100 and 100 <= _dtbl[5-_i][4][9] then _i := 5-_i; _dtbl[4] := _i; _j := round(_dtbl[_i][4][17]); return round(_dtbl[_i][3][1][_j, 1]) elif 100 <= _dtbl[_i][4][9] then _j := round(_dtbl[_i][4][17]); return round(_dtbl[_i][3][1][_j, 1]) else return 0 end if elif _xin = "eventstatus" then if _nv = 0 then error "this solution has no events" end if; _i := [selectremove(proc (a) options operator, arrow; _dtbl[1][3][1][a, 7] = 1 end proc, {seq(_j, _j = 1 .. round(_dtbl[1][3][1][_nv+1, 1]))})]; return ':-enabled' = _i[1], ':-disabled' = _i[2] elif _xin = "eventclear" then if _nv = 0 then error "this solution has no events" end if; _i := _dtbl[4]; if _i <> 2 and _i <> 3 then error "no events to clear" end if; if _dtbl[_i][4][10] = 1 and assigned(_dtbl[5-_i]) and _dtbl[_i][4][9] < 100 and 100 < _dtbl[5-_i][4][9] then _dtbl[4] := 5-_i; _i := 5-_i end if; if _dtbl[_i][4][9] < 100 then error "no events to clear" elif _nv < _dtbl[_i][4][9]-100 then error "event error condition cannot be cleared" else _j := _dtbl[_i][4][9]-100; if irem(round(_dtbl[_i][3][1][_j, 4]), 2) = 1 then error "retriggerable events cannot be cleared" end if; _j := round(_dtbl[_i][3][1][_j, 1]); for _k to _nv do if _dtbl[_i][3][1][_k, 1] = _j then if _dtbl[_i][3][1][_k, 2] = 3 then error "range events cannot be cleared" end if; _dtbl[_i][3][1][_k, 8] := _dtbl[_i][3][1][_nv+1, 8] end if end do; _dtbl[_i][4][17] := 0; _dtbl[_i][4][9] := 0; if _dtbl[1][4][10] = 1 then if _i = 2 then try procname(procname("left")) catch:  end try else try procname(procname("right")) catch:  end try end if end if end if; return  elif type(_xin, `=`) and member(lhs(_xin), {"eventdisable", "eventenable"}) then if _nv = 0 then error "this solution has no events" end if; if type(rhs(_xin), {('list')('posint'), ('set')('posint')}) then _i := {op(rhs(_xin))} elif type(rhs(_xin), 'posint') then _i := {rhs(_xin)} else error "event identifiers must be integers in the range 1..%1", round(_dtbl[1][3][1][_nv+1, 1]) end if; if select(proc (a) options operator, arrow; _nv < a end proc, _i) <> {} then error "event identifiers must be integers in the range 1..%1", round(_dtbl[1][3][1][_nv+1, 1]) end if; _k := {}; for _j to _nv do if member(round(_dtbl[1][3][1][_j, 1]), _i) then _k := `union`(_k, {_j}) end if end do; _i := _k; if lhs(_xin) = "eventdisable" then _dtbl[4] := 0; _j := [evalb(assigned(_dtbl[2]) and member(_dtbl[2][4][17], _i)), evalb(assigned(_dtbl[3]) and member(_dtbl[3][4][17], _i))]; for _k in _i do _dtbl[1][3][1][_k, 7] := 0; if assigned(_dtbl[2]) then _dtbl[2][3][1][_k, 7] := 0 end if; if assigned(_dtbl[3]) then _dtbl[3][3][1][_k, 7] := 0 end if end do; if _j[1] then for _k to _nv+1 do if _k <= _nv and not type(_dtbl[2][3][4][_k, 1], 'undefined') then userinfo(3, {'events', 'eventreset'}, `reinit #2, event code `, _k, ` to defined init `, _dtbl[2][3][4][_k, 1]); _dtbl[2][3][1][_k, 8] := _dtbl[2][3][4][_k, 1] elif _dtbl[2][3][1][_k, 2] = 0 and irem(iquo(round(_dtbl[2][3][1][_k, 4]), 32), 2) = 1 then userinfo(3, {'events', 'eventreset'}, `reinit #2, event code `, _k, ` to rate hysteresis init `, _dtbl[2][5][24]); _dtbl[2][3][1][_k, 8] := _dtbl[2][5][24] elif _dtbl[2][3][1][_k, 2] = 0 and irem(iquo(round(_dtbl[2][3][1][_k, 4]), 2), 2) = 0 then userinfo(3, {'events', 'eventreset'}, `reinit #2, event code `, _k, ` to initial init `, _x0); _dtbl[2][3][1][_k, 8] := _x0 else userinfo(3, {'events', 'eventreset'}, `reinit #2, event code `, _k, ` to fireinitial init `, _x0-1); _dtbl[2][3][1][_k, 8] := _x0-1 end if end do; _dtbl[2][4][17] := 0; _dtbl[2][4][9] := 0; if _dtbl[1][4][10] = 1 then procname(procname("left")) end if end if; if _j[2] then for _k to _nv+1 do if _k <= _nv and not type(_dtbl[3][3][4][_k, 2], 'undefined') then userinfo(3, {'events', 'eventreset'}, `reinit #3, event code `, _k, ` to defined init `, _dtbl[3][3][4][_k, 2]); _dtbl[3][3][1][_k, 8] := _dtbl[3][3][4][_k, 2] elif _dtbl[3][3][1][_k, 2] = 0 and irem(iquo(round(_dtbl[3][3][1][_k, 4]), 32), 2) = 1 then userinfo(3, {'events', 'eventreset'}, `reinit #3, event code `, _k, ` to rate hysteresis init `, _dtbl[3][5][24]); _dtbl[3][3][1][_k, 8] := _dtbl[3][5][24] elif _dtbl[3][3][1][_k, 2] = 0 and irem(iquo(round(_dtbl[3][3][1][_k, 4]), 2), 2) = 0 then userinfo(3, {'events', 'eventreset'}, `reinit #3, event code `, _k, ` to initial init `, _x0); _dtbl[3][3][1][_k, 8] := _x0 else userinfo(3, {'events', 'eventreset'}, `reinit #3, event code `, _k, ` to fireinitial init `, _x0+1); _dtbl[3][3][1][_k, 8] := _x0+1 end if end do; _dtbl[3][4][17] := 0; _dtbl[3][4][9] := 0; if _dtbl[1][4][10] = 1 then procname(procname("right")) end if end if else for _k in _i do _dtbl[1][3][1][_k, 7] := 1 end do; _dtbl[2] := evaln(_dtbl[2]); _dtbl[3] := evaln(_dtbl[3]); _dtbl[4] := 0; if _dtbl[1][4][10] = 1 then if _x0 <= procname("right") then try procname(procname("right")) catch:  end try end if; if procname("left") <= _x0 then try procname(procname("left")) catch:  end try end if end if end if; return  elif type(_xin, `=`) and lhs(_xin) = "eventfired" then if not type(rhs(_xin), 'list') then error "'eventfired' must be specified as a list" end if; if _nv = 0 then error "this solution has no events" end if; if _dtbl[4] <> 2 and _dtbl[4] <> 3 then error "'direction' must be set prior to calling/setting 'eventfired'" end if; _i := _dtbl[4]; _val := NULL; if not assigned(_EnvEventRetriggerWarned) then _EnvEventRetriggerWarned := false end if; for _k in rhs(_xin) do if type(_k, 'integer') then _src := _k elif type(_k, 'integer' = 'anything') and type(evalf(rhs(_k)), 'numeric') then _k := lhs(_k) = evalf[max(Digits, 18)](rhs(_k)); _src := lhs(_k) else error "'eventfired' entry is not valid: %1", _k end if; if _src < 1 or round(_dtbl[1][3][1][_nv+1, 1]) < _src then error "event identifiers must be integers in the range 1..%1", round(_dtbl[1][3][1][_nv+1, 1]) end if; _src := {seq(`if`(_dtbl[1][3][1][_j, 1]-_src = 0., _j, NULL), _j = 1 .. _nv)}; if nops(_src) <> 1 then error "'eventfired' can only be set/queried for root-finding events and time/interval events" end if; _src := _src[1]; if _dtbl[1][3][1][_src, 2] <> 0. and _dtbl[1][3][1][_src, 2]-2. <> 0. then error "'eventfired' can only be set/queried for root-finding events and time/interval events" elif irem(round(_dtbl[1][3][1][_src, 4]), 2) = 1 then if _EnvEventRetriggerWarned = false then WARNING(`'eventfired' has no effect on events that retrigger`) end if; _EnvEventRetriggerWarned := true end if; if _dtbl[_i][3][1][_src, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_src, 4]), 32), 2) = 1 then _val := _val, undefined elif type(_dtbl[_i][3][4][_src, _i-1], 'undefined') or _i = 2 and _dtbl[2][3][1][_src, 8] < _dtbl[2][3][4][_src, 1] or _i = 3 and _dtbl[3][3][4][_src, 2] < _dtbl[3][3][1][_src, 8] then _val := _val, _dtbl[_i][3][1][_src, 8] else _val := _val, _dtbl[_i][3][4][_src, _i-1] end if; if type(_k, `=`) then if _dtbl[_i][3][1][_src, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_src, 4]), 32), 2) = 1 then error "cannot set event code for a rate hysteresis event" end if; userinfo(3, {'events', 'eventreset'}, `manual set event code `, _src, ` to value `, rhs(_k)); _dtbl[_i][3][1][_src, 8] := rhs(_k); _dtbl[_i][3][4][_src, _i-1] := rhs(_k) end if end do; return [_val] elif type(_xin, `=`) and lhs(_xin) = "direction" then if not member(rhs(_xin), {-1, 1, ':-left', ':-right'}) then error "'direction' must be specified as either '1' or 'right' (positive) or '-1' or 'left' (negative)" end if; _src := `if`(_dtbl[4] = 2, -1, `if`(_dtbl[4] = 3, 1, undefined)); _i := `if`(member(rhs(_xin), {1, ':-right'}), 3, 2); _dtbl[4] := _i; _dtbl[_i] := `dsolve/numeric/SC/IVPdcopy`(_dtbl[1], `if`(assigned(_dtbl[_i]), _dtbl[_i], NULL)); if 0 < _nv then for _j to _nv+1 do if _j <= _nv and not type(_dtbl[_i][3][4][_j, _i-1], 'undefined') then userinfo(3, {'events', 'eventreset'}, `reinit #4, event code `, _j, ` to defined init `, _dtbl[_i][3][4][_j, _i-1]); _dtbl[_i][3][1][_j, 8] := _dtbl[_i][3][4][_j, _i-1] elif _dtbl[_i][3][1][_j, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_j, 4]), 32), 2) = 1 then userinfo(3, {'events', 'eventreset'}, `reinit #4, event code `, _j, ` to rate hysteresis init `, _dtbl[_i][5][24]); _dtbl[_i][3][1][_j, 8] := _dtbl[_i][5][24] elif _dtbl[_i][3][1][_j, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_j, 4]), 2), 2) = 0 then userinfo(3, {'events', 'eventreset'}, `reinit #4, event code `, _j, ` to initial init `, _x0); _dtbl[_i][3][1][_j, 8] := _x0 else userinfo(3, {'events', 'eventreset'}, `reinit #4, event code `, _j, ` to fireinitial init `, _x0-2*_i+5.0); _dtbl[_i][3][1][_j, 8] := _x0-2*_i+5.0 end if end do end if; return _src elif _xin = "eventcount" then if _dtbl[1][3][1] = 0 or _dtbl[4] <> 2 and _dtbl[4] <> 3 then return 0 else return round(_dtbl[_dtbl[4]][3][1][_nv+1, 12]) end if else return "procname" end if end if; if _xout = _x0 then return [_x0, seq(evalf(_dtbl[1][6][_vmap[_i]]), _i = 1 .. _n-_ne)] end if; _i := `if`(_x0 <= _xout, 3, 2); if _xin = "last" and 0 < _dtbl[_i][4][9] and _dtbl[_i][4][9] < 100 then _dat := eval(_dtbl[_i], 2); _j := _dat[4][20]; return [_dat[11][_j, 0], seq(_dat[11][_j, _vmap[_i]], _i = 1 .. _n-_ne-_nd), seq(_dat[8][1][_vmap[_i]], _i = _n-_ne-_nd+1 .. _n-_ne)] end if; if not type(_dtbl[_i], 'array') then _dtbl[_i] := `dsolve/numeric/SC/IVPdcopy`(_dtbl[1], `if`(assigned(_dtbl[_i]), _dtbl[_i], NULL)); if 0 < _nv then for _j to _nv+1 do if _j <= _nv and not type(_dtbl[_i][3][4][_j, _i-1], 'undefined') then userinfo(3, {'events', 'eventreset'}, `reinit #5, event code `, _j, ` to defined init `, _dtbl[_i][3][4][_j, _i-1]); _dtbl[_i][3][1][_j, 8] := _dtbl[_i][3][4][_j, _i-1] elif _dtbl[_i][3][1][_j, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_j, 4]), 32), 2) = 1 then userinfo(3, {'events', 'eventreset'}, `reinit #5, event code `, _j, ` to rate hysteresis init `, _dtbl[_i][5][24]); _dtbl[_i][3][1][_j, 8] := _dtbl[_i][5][24] elif _dtbl[_i][3][1][_j, 2] = 0 and irem(iquo(round(_dtbl[_i][3][1][_j, 4]), 2), 2) = 0 then userinfo(3, {'events', 'eventreset'}, `reinit #5, event code `, _j, ` to initial init `, _x0); _dtbl[_i][3][1][_j, 8] := _x0 else userinfo(3, {'events', 'eventreset'}, `reinit #5, event code `, _j, ` to fireinitial init `, _x0-2*_i+5.0); _dtbl[_i][3][1][_j, 8] := _x0-2*_i+5.0 end if end do end if end if; if _xin <> "last" then if 0 < 0 then if `dsolve/numeric/checkglobals`(op(_dtbl[1][14]), _pars, _n, _y0) then `dsolve/numeric/SC/reinitialize`(_dtbl, _y0, _n, procname, _pars, _i) end if end if; if _dtbl[1][4][7] = 0 then error "parameters must be initialized before solution can be computed" end if end if; _dat := eval(_dtbl[_i], 2); _dtbl[4] := _i; try _src := `dsolve/numeric/SC/IVPrun`(_dat, _xout) catch: userinfo(2, `dsolve/debug`, print(`Exception in solnproc:`, [lastexception][2 .. -1])); error  end try; if _src = 0 and 100 < _dat[4][9] then _val := _dat[3][1][_nv+1, 8] else _val := _dat[11][_dat[4][20], 0] end if; if _src <> 0 or _dat[4][9] <= 0 then _dtbl[1][5][1] := _xout else _dtbl[1][5][1] := _val end if; if _i = 3 and _val < _xout then Rounding := -infinity; if _dat[4][9] = 1 then error "cannot evaluate the solution further right of %1, probably a singularity", evalf[8](_val) elif _dat[4][9] = 2 then error "cannot evaluate the solution further right of %1, maxfun limit exceeded (see ?dsolve,maxfun for details)", evalf[8](_val) elif _dat[4][9] = 3 then if _dat[4][25] = 3 then error "cannot evaluate the solution past the initial point, problem may be initially singular or improperly set up" else error "cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up" end if elif _dat[4][9] = 4 then error "cannot evaluate the solution further right of %1, accuracy goal cannot be achieved with specified 'minstep'", evalf[8](_val) elif _dat[4][9] = 5 then error "cannot evaluate the solution further right of %1, too many step failures, tolerances may be too loose for problem", evalf[8](_val) elif _dat[4][9] = 6 then error "cannot evaluate the solution further right of %1, cannot downgrade delay storage for problems with delay derivative order > 1, try increasing delaypts", evalf[8](_val) elif _dat[4][9] = 10 then error "cannot evaluate the solution further right of %1, interrupt requested", evalf[8](_val) elif 100 < _dat[4][9] then if _dat[4][9]-100 = _nv+1 then error "constraint projection failure on event at t=%1", evalf[8](_val) elif _dat[4][9]-100 = _nv+2 then error "index-1 and derivative evaluation failure on event at t=%1", evalf[8](_val) elif _dat[4][9]-100 = _nv+3 then error "maximum number of event iterations reached (%1) at t=%2", round(_dat[3][1][_nv+1, 3]), evalf[8](_val) else if _Env_dsolve_nowarnstop <> true then `dsolve/numeric/warning`(StringTools:-FormatMessage("cannot evaluate the solution further right of %1, event #%2 triggered a halt", evalf[8](_val), round(_dat[3][1][_dat[4][9]-100, 1]))) end if; Rounding := 'nearest'; _xout := _val end if else error "cannot evaluate the solution further right of %1", evalf[8](_val) end if elif _i = 2 and _xout < _val then Rounding := infinity; if _dat[4][9] = 1 then error "cannot evaluate the solution further left of %1, probably a singularity", evalf[8](_val) elif _dat[4][9] = 2 then error "cannot evaluate the solution further left of %1, maxfun limit exceeded (see ?dsolve,maxfun for details)", evalf[8](_val) elif _dat[4][9] = 3 then if _dat[4][25] = 3 then error "cannot evaluate the solution past the initial point, problem may be initially singular or improperly set up" else error "cannot evaluate the solution past the initial point, problem may be complex, initially singular or improperly set up" end if elif _dat[4][9] = 4 then error "cannot evaluate the solution further left of %1, accuracy goal cannot be achieved with specified 'minstep'", evalf[8](_val) elif _dat[4][9] = 5 then error "cannot evaluate the solution further left of %1, too many step failures, tolerances may be too loose for problem", evalf[8](_val) elif _dat[4][9] = 6 then error "cannot evaluate the solution further left of %1, cannot downgrade delay storage for problems with delay derivative order > 1, try increasing delaypts", evalf[8](_val) elif _dat[4][9] = 10 then error "cannot evaluate the solution further right of %1, interrupt requested", evalf[8](_val) elif 100 < _dat[4][9] then if _dat[4][9]-100 = _nv+1 then error "constraint projection failure on event at t=%1", evalf[8](_val) elif _dat[4][9]-100 = _nv+2 then error "index-1 and derivative evaluation failure on event at t=%1", evalf[8](_val) elif _dat[4][9]-100 = _nv+3 then error "maximum number of event iterations reached (%1) at t=%2", round(_dat[3][1][_nv+1, 3]), evalf[8](_val) else if _Env_dsolve_nowarnstop <> true then `dsolve/numeric/warning`(StringTools:-FormatMessage("cannot evaluate the solution further left of %1, event #%2 triggered a halt", evalf[8](_val), round(_dat[3][1][_dat[4][9]-100, 1]))) end if; Rounding := 'nearest'; _xout := _val end if else error "cannot evaluate the solution further left of %1", evalf[8](_val) end if end if; if _EnvInFsolve = true then _dig := _dat[4][26]; _dat[4][26] := _EnvDSNumericSaveDigits; _Env_dsolve_SC_native := true; if _dat[4][25] = 1 then _i := 1; _dat[4][25] := 2 else _i := _dat[4][25] end if; _val := `dsolve/numeric/SC/IVPval`(_dat, _xout, _src); _dat[4][25] := _i; _dat[4][26] := _dig; [_xout, seq(_val[_vmap[_i]], _i = 1 .. _n-_ne)] else Digits := _dat[4][26]; _val := `dsolve/numeric/SC/IVPval`(eval(_dat, 2), _xout, _src); [_xout, seq(_val[_vmap[_i]], _i = 1 .. _n-_ne)] end if end proc, (2) = Array(0..0, {}), (3) = [t, f(t)], (4) = []}); _vars := _dat[3]; _pars := map(rhs, _dat[4]); _n := nops(_vars)-1; _solnproc := _dat[1]; if not type(_xout, 'numeric') then if member(x_rkf45, ["start", 'start', "method", 'method', "left", 'left', "right", 'right', "leftdata", "rightdata", "enginedata", "eventstop", 'eventstop', "eventclear", 'eventclear', "eventstatus", 'eventstatus', "eventcount", 'eventcount', "laxtol", 'laxtol', "numfun", 'numfun', NULL]) then _res := _solnproc(convert(x_rkf45, 'string')); if 1 < nops([_res]) then return _res elif type(_res, 'array') then return eval(_res, 1) elif _res <> "procname" then return _res end if elif member(x_rkf45, ["last", 'last', "initial", 'initial', "parameters", 'parameters', "initial_and_parameters", 'initial_and_parameters', NULL]) then _xout := convert(x_rkf45, 'string'); _res := _solnproc(_xout); if _xout = "parameters" then return [seq(_pars[_i] = _res[_i], _i = 1 .. nops(_pars))] elif _xout = "initial_and_parameters" then return [seq(_vars[_i+1] = [_res][1][_i+1], _i = 0 .. _n), seq(_pars[_i] = [_res][2][_i], _i = 1 .. nops(_pars))] else return [seq(_vars[_i+1] = _res[_i+1], _i = 0 .. _n)] end if elif type(_xout, `=`) and member(lhs(_xout), ["initial", 'initial', "parameters", 'parameters', "initial_and_parameters", 'initial_and_parameters', NULL]) then _xout := convert(lhs(x_rkf45), 'string') = rhs(x_rkf45); if type(rhs(_xout), 'list') then _res := _solnproc(_xout) else error "initial and/or parameter values must be specified in a list" end if; if lhs(_xout) = "initial" then return [seq(_vars[_i+1] = _res[_i+1], _i = 0 .. _n)] elif lhs(_xout) = "parameters" then return [seq(_pars[_i] = _res[_i], _i = 1 .. nops(_pars))] else return [seq(_vars[_i+1] = [_res][1][_i+1], _i = 0 .. _n), seq(_pars[_i] = [_res][2][_i], _i = 1 .. nops(_pars))] end if elif type(_xout, `=`) and member(lhs(_xout), ["eventdisable", 'eventdisable', "eventenable", 'eventenable', "eventfired", 'eventfired', "direction", 'direction', NULL]) then return _solnproc(convert(lhs(x_rkf45), 'string') = rhs(x_rkf45)) elif _xout = "solnprocedure" then return eval(_solnproc) elif _xout = "sysvars" then return _vars end if; if procname <> unknown then return ('procname')(x_rkf45) else _ndsol; _ndsol := pointto(_dat[2][0]); return ('_ndsol')(x_rkf45) end if end if; try _res := _solnproc(_xout); [seq(_vars[_i+1] = _res[_i+1], _i = 0 .. _n)] catch: error  end try end proc

 

Warning, cannot evaluate the solution further right of .14193434, probably a singularity

 

 

 


 

Download modest_contribution.mw

@dharr 

I guess you refer to the sentence "I have reason to expect that this pattern will repeat for successive points (i.e. points 13, 14, ..., 30)"?
I wasn't sure to understand it correctly, in particular that [13, y[13]] was equal to [1, y[1]].

This is why I said that the OP would have specified either   [ [0, p[-1][2]], p[ ] ]   or  [ p[ ], [13, p[1][2]] ]
 

@erik10

Time and memory comparisons
 

restart
f1 := proc(Bins, Probs, N)
  local X, S;
  uses Statistics:
  UseHardwareFloats := false:
  X := RandomVariable(ProbabilityTable(Probs));
  S := round~(Sample(X, Vector(N, datatype=float))):
  Bins[convert(S, list)]
end proc:

f2 := proc(Bins, Probs, N)
  local X, S;
  uses Statistics:
  UseHardwareFloats := false:
  X := RandomVariable(EmpiricalDistribution(Bins, 'probabilities'=Probs)):
  S := Sample(X, N);
  round~(S)
end proc:

Probs := [0.10, 0.30, 0.20, 0.25, 0.15]:
Bins  := <50, 60, 70, 80, 90>:

S1 := CodeTools:-Usage(f1(Bins, Probs, 10^4)):
S2 := CodeTools:-Usage(f2(Bins, Probs, 10^4)):
memory used=13.89MiB, alloc change=32.00MiB, cpu time=120.00ms, real time=120.00ms, gc time=13.84ms
memory used=18.76MiB, alloc change=0 bytes, cpu time=96.00ms, real time=96.00ms, gc time=0ns
Statistics:-Tally(S1);
Statistics:-Tally(S2)
    [50 = 1005, 60 = 2989, 70 = 2035, 90 = 1428, 80 = 2543]
    [50 = 1012, 60 = 3033, 70 = 2076, 90 = 1442, 80 = 2437]

Download Comparison.mw

@Carl Love @vv  @Axel Vogt



Maybe not as simple as that for the original paper seems to contain a lot of typos (a lot of them come probably from digitalization of the original paper).
For instance, in procedure "av" the line 
for i: = i— 1while co eps2 < p A i > 0 do
co x eps must probably be intended as co * eps  and   as /\ (for "and").
But what about for i: = i— 1whose syntax is not correct (even if "—" one must likely read as "-")

Given the problem (multimodal optimization) I understand "search of the global minimum (minima?) of a function with several local minima". For Axel: I'm not familiar with the "DirectSearch" package, does-it handles this kind of problem?
Ideally, but this is non free toolbox, GlobalOptimization seems more suited.

The fact the function is noisy was an anusual point by the time the original article has been published (1980). 
But it is today a subject widely investigated, and this  for at least 20 years, and a lot of efficient methods do exist to address this problem (see for instance scholar by the same author antanas žilinskas).
So I think it's probably better and simpler to implement in Maple a "modern" algorithm (or to use and adapt something already existing in Maple) instead of this old algorithm that we are not even sure it doesn't contain more ambiguous typos.

@dohashi  @Carl Love


Parallel programming being recurrently mentioned here, don't you think that all the courses, tips, advices, answers that both of you, and a few others, have done on the subject of parallel programming would be worth compiling?
Mapleprime's advanced search can help find useful information, but, with the exception of Dohashi's courses, it remains (IMO) too scattered to be really effective.

Pretty work!

When I was studying mechanics, years ago, I discovered Timoshenko's books and I still have the one I bought for a research project.
It was entitled "Théorie des vibrations" (in french, translates as "Vibration Theory"), and your work prompted me to reopen it. There's a whole chapter on "Lateral Vibration of Prismatic Beams". At that time (1954), the term "Krylov-Duncan" did not seem to be used (at least Timoshenko did not use it in this book).
Your work takes me back years and I read it with great pleasure.

 

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