MaplePrimes Questions

I have a set of points. I want to make a linear spline of that points and plot the resulting function:

function:=CurveFitting[Spline](points_x,points_y,x,degree=1):

However I need the function to define constant y endpoint values where x is out of points_x range (i.e. first-derivation is zero where x is out of points_x range). Endpoint options does not work for me.

             constant1   x < xmin
function :=  ..
             constant2   otherwise

How can I define spline function like this?

Having difficulties solving pde. Below is the problem and its not plotting. Anyone with useful informations. Please

restart;
with(PDEtools, casesplit, declare);
with(DEtools, gensys);
with(Physics);

PDE := diff(theta(x, t), x, x)+beta*theta(x, t)*(diff(theta(x, t), x, x))+beta*((diff(theta(x, t), x))^2)-M^2*theta(x, t)-S[h]*(theta(x, t)^2)+M^2*G*(1+E*theta(x, t))-P[e]*(diff(theta(x, t), x)) = diff(theta(x, t), t);
/ d  / d             \\
|--- |--- theta(x, t)||
\ dx \ dx            //

                      / d  / d             \\
   + beta theta(x, t) |--- |--- theta(x, t)||
                      \ dx \ dx            //

                           2                                     
          / d             \     2                               2
   + beta |--- theta(x, t)|  - M  theta(x, t) - S[h] theta(x, t) 
          \ dx            /                                      

      2                              / d             \    d  
   + M  G (1 + E theta(x, t)) - P[e] |--- theta(x, t)| = --- 
                                     \ dx            /    dt 

  theta(x, t)
BC := theta(x, 0) = 0, Dt(theta(0, t)) = 0, theta(1, t) = 1;
     theta(x, 0) = 0, Dt(theta(0, t)) = 0, theta(1, t) = 1
Codes := [beta = .1, M = .1, S[h] = .1, G = .1, P[e] = .1, E = .1];
S1 := pdsolve({BC, subs(Codes, PDE)});
PDEplot(S1, [[t, theta(x, t)], [x, theta(x, t)]], t = 0 .. 1, x = 0 .. 1, iterations = 2, numchar = [10, 10], stepsize = 0.5e-1, numsteps = [-5, 5]);
   PDEplot([[t, theta(x, t)], [x, theta(x, t)]], t = 0 .. 1, 

     x = 0 .. 1, iterations = 2, numchar = [10, 10], 

     stepsize = 0.05, numsteps = [-5, 5])

 

I've got Maple 2017 linked to MATLAB R2017a but I can't get MATLAB R2017a linked to Maple 2017.

I've got MATLAB R2016b linked to Maple 2017.

Any ideas? (Or do I just need to wait for an update?)

Hello guys!

Could you tell me what are the state-of-the-art algorithms to compute Hermite and Smith normal forms (well or just Hermite since the later can be computed by applying Hermite twice)? I am interested in these algorihtms which outputs also the respective unimodular matrices.

 

hello...i have a problem with this program.

I want to save the result(y,u(y)) in a text or another format file, but I encounter with this error message:

Error, (in fprintf) number expected for floating point formatBVP.mw
 

restart:

A1:= 5.5:  n:= 0.59:  A2:= 11818.:  h0:= 0.402e-3:
L:= .1:  dpx := -11823.9:  uc:= 0.44e-2:

ODE:= (A3,y)->
   (h0^(n+1)*L/sqrt(n)*(A1*exp(sqrt(n)*y/L)-A2*exp(-sqrt(n)*y/L))+dpx*y*h0^(n+1)+A3*(h0)^n)^(1/n)
;

proc (A3, y) options operator, arrow; (h0^(n+1)*L*(A1*exp(sqrt(n)*y/L)-A2*exp(-sqrt(n)*y/L))/sqrt(n)+dpx*y*h0^(n+1)+A3*h0^n)^(1/n) end proc

(1)

ODEINT:= proc(A3)
option remember;
local y;
   evalf(Int(ODE(A3,y), y= 0..1, epsilon= 1e-7)) - uc
end proc:

ReINT:= proc(A3x, A3y)
   Digits:= 15:
   Re(ODEINT(A3x + I*A3y))
end proc:

ImINT:= subs(Re= Im, eval(ReINT)):

Digits:= 7:
a3:= fsolve([ReINT, ImINT]);

[6.3610757968979, 0.]

(2)

A3:= Complex(a3[]);

6.3610757968979+0.*I

(3)

Solve as IVP:

Digits:= 15:
sol:= dsolve({diff(u(y),y) = ODE(A3,y), u(0)=0}, numeric, range=0..1,  output=listprocedure):

``

``

plots:-odeplot(
   sol, [[y, Re(u(y))], [y, Im(u(y))]], y= 0..1,
   legend= [real, imag], labels= [y, u(y)]
);

 

 

F53 := proc (y) options operator, arrow; U end proc; G53 := proc (y) options operator, arrow; Re(evalf[20](F53(y))) end proc; Temp3 := cat("u(y)-y.dat"); fd53 := fopen(Temp3, WRITE, TEXT); for i from 0 by 0.5e-1 to 1 do tt := i; u := eval(G53(y), y = tt); fprintf(fd53, "%10.5e %10.5e  \n", tt, u) end do; fclose(fd53)

Error, (in fprintf) number expected for floating point format

 

NULL


 

Download BVP.mw

 

please help me

thanks

According to the help page:
interface(displayprecision=n)
sets the number of decimal places to be displayed to n.
But this is true only if interface(typesetting=extended).
For interface(typesetting=standard),  n represents the number of decimal places after the decimal point.
Is there any reason for this decision?

restart;
x:=123.456789012345:
interface(displayprecision=4):
interface(typesetting=standard): x;

                        123.4568
interface(typesetting=extended): x;
                        123.5

 

 

I'm trying to calculate forces between particles. I defined all my variables and the equation for force, but when I plug it all in, it gives me 0 when I know for a fact it's not 0. I should be getting something like f12=-0.4, f13=-0.24, and f23=-0.5.

 

failforce.mw

 

Basically I defined variables like x1,y1, m1 , etc. and made my force equation fij with all variables having appropriate i and j subscripts.

hello. i want to write this function with  "for"loop. but i don't know
1.mw

Hello!
Used PolyhedralSets for plotting.
At the moment there are a number of questions in the construction of graphs:
How to adjust the rotation of this figure around the z axis?
How to make, what color of a figure received in a cut would be much darker or Darker color?

with(PolyhedralSets);
P1 := PolyhedralSet({-x-20 <= 0, -x-20 <= 20-y, -x-20 <= -(1/2)*y, -x-20 <= -z, -x-20 <= -(x+y)*(1/2), -x-20 <= -(y+z)*(1/2)});
Plot(P1, axe
s = normal, view = [-40 .. 40, -40 .. 40, -40 .. 40], orientation = [30, -30, -60], color = blue, thickness = 2);
Plot(P1, axes = normal, view = [-40 .. 40, -40 .. 40, -40 .. -40], orientation = [0, 0, 0], color = blue, thickness = 2)





I'm trying to obtain integral of Planck radiation law in Maple:

with this command:

f := (2*h*(c)^(2))/((x)^(5))*(1)/(exp((h*c)/(x*k*T))-1);
int(f,x=0..infinity);

but I get some terrible limit that cannot be solved instead of the correct result:

How to obtain correct integral?

planck.mw

I followed the basic example RLS circuit first. It worked out well for R = 24 ohms, L = 160 mHand C = 200 microF. Signal is step input h = 1 and  t0 =  0.1 s. Simulation td = 0.5 s

When I extended it for DC motor, the output for torque (tou) and speed (w) not plotted for h = 1  t0 =  1s and simulation td = 5 s for the same parameters as above the output required (shown in manual) is not coming. Is it because default values shown were different? Then how do i change? I am enclosing the file for view and help.

DCmotort_model1.msim

 

Thanks.

Ramakrishnan V

How to label in inline math mode. I tried labels = ['theta', Typesetting:-Typeset(cos(1/theta)/sqrt(1-theta^2))] which gives a big expression on Y axis spreaded in two lines. But i want to label one line as in latex $\cos(1/\theta)/sqrt(1-\theta^2))$ . Is there a way to do it ?

 

the program shows that the error please verify it sirprogram11.mw

Hello,

I have an industrial robot model and I need to define constraints for the revolute joints. For example, R2 joint is only allowed to move between -165 to 165 degrees. Could you please tell me how I can impose these constraints?

Thank you.

Önder

what's the problem with PDE below? tnx for help


 

restart:

PDE:=diff(u(x,t),t)=k*diff(u(x,t),x$2)-h*u(x,t);

diff(u(x, t), t) = k*(diff(diff(u(x, t), x), x))-h*u(x, t)

(1)

IBC := {u(-Pi,t)=u(Pi,t), (D[1](u))(-Pi, t) = (D[1](u))(Pi, t),u(x,0)=sin(x)};

{u(x, 0) = sin(x), u(-Pi, t) = u(Pi, t), (D[1](u))(-Pi, t) = (D[1](u))(Pi, t)}

(2)

pdsolve(PDE,IBC);

Error, (in pdsolve/sys) too many arguments; some or all of the following are wrong: [{u(x, t)}, {u(x, 0) = sin(x), u(-Pi, t) = u(Pi, t), (D[1](u))(-Pi, t) = (D[1](u))(Pi, t)}]

 

 


 

Download PDE_problem.mw

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