MaplePrimes Questions

Hello experts,

I am trying to use solve to find a solution to a system of two equations. The two equations involved are quite complicated, and so sometimes Maple has difficulty with this. In particular, the solve command tries evaluating but never comes up with a solution (I've waited at least an hour, before giving up). 

I recently learned about fsolve, which gives approximate numeric solutions (which would be fine for my purposes), but fsolve too struggles with a solution and simply returns my input to me. I tried plotting the system of equations using plots:-implictplot to see if a solution existed, and as expected it does. I was hoping to get some tips on trying to solve a difficult system like this, perhaps given the knowledge that a solution definitely exists. Unfortunately, I need a solution for many variations of the same system, so simply reading off the approximate solution isn't really an option.

In my attatched code, the system with W = 49 is the first one where Maple really begins to struggle, and I believe that solutions for W>49 are also difficult.

06042020_Predicting_w_AB_Ratio_Maple_Primes.mw

Thanks!

Hello

I need to count and separate the nonlinear terms in a list.  Example:

w:=[[z, y, x, 1], [x*z, x*y, y, 1], [x*z, z, x*y]];

there are 4 nonlinear terms, x*z, x*y, x*z, and x*y.  

The terms can be any combination of the given variables, that is, x, y, and z.  

My solution to the problem of counting the nonlinear terms is 

aux1:=[seq([seq(nops(w[j,i]),i=1..nops(w[j]))],j=1..nops(w))];

aux2:=[seq(selectremove(x->x>1,aux1[i])[1],i=1..nops(aux1))]

res:=convert([seq(convert(nops(aux2[i]),`+`),i=1..nops(aux2))],`+`);

It works but I wonder whether there is a better solution that includes showing the nonlinear terms themselves.

Many thanks

Ed

Cannot find integration proplem_in_maple.mw

restart

with(LinearAlgebra)

with(orthopoly)

``

with(student)

Digits := 32

32

(1)

interface(rtablesize = 100)

10

(2)

a := 0; b := 1; N := 5; h := (b-a)/N; B[0] := 1; B[1] := x; n := 2; B[2] := x^2+2; alpha := 1/2

0

 

1

 

5

 

1/5

 

1

 

x

 

2

 

x^2+2

 

1/2

(3)

NULL

for j from 3 to N do B[j] := expand(x*B[j-1]-B[j-2]) end do

x^3+x

 

x^4-2

 

x^5-3*x-x^3

(4)

for i from 0 to N do x[i] := h*i+a end do

0

 

1/5

 

2/5

 

3/5

 

4/5

 

1

(5)

y := sum(c[s]*B[s], s = 0 .. N)

c[0]+c[1]*x+c[2]*(x^2+2)+c[3]*(x^3+x)+c[4]*(x^4-2)+c[5]*(x^5-3*x-x^3)

(6)

yt := subs(x = t, y)

c[0]+c[1]*t+c[2]*(t^2+2)+c[3]*(t^3+t)+c[4]*(t^4-2)+c[5]*(t^5-3*t-t^3)

(7)

k := expand(int(yt*sin(t)*x, t = 0 .. x))

x*c[0]+22*x*c[4]-c[1]*cos(x)*x^2-c[2]*cos(x)*x^3+2*c[2]*sin(x)*x^2-c[3]*cos(x)*x^4+3*c[3]*sin(x)*x^3+5*c[3]*cos(x)*x^2-c[4]*cos(x)*x^5+4*c[4]*sin(x)*x^4+12*c[4]*cos(x)*x^3-24*c[4]*sin(x)*x^2-c[5]*cos(x)*x^6+5*c[5]*sin(x)*x^5+21*c[5]*cos(x)*x^4-63*c[5]*sin(x)*x^3-123*c[5]*cos(x)*x^2-x*cos(x)*c[0]-22*x*cos(x)*c[4]+x*c[1]*sin(x)-5*x*c[3]*sin(x)+123*x*c[5]*sin(x)

(8)

k4 := k*y

(x*c[0]+22*x*c[4]-c[1]*cos(x)*x^2-c[2]*cos(x)*x^3+2*c[2]*sin(x)*x^2-c[3]*cos(x)*x^4+3*c[3]*sin(x)*x^3+5*c[3]*cos(x)*x^2-c[4]*cos(x)*x^5+4*c[4]*sin(x)*x^4+12*c[4]*cos(x)*x^3-24*c[4]*sin(x)*x^2-c[5]*cos(x)*x^6+5*c[5]*sin(x)*x^5+21*c[5]*cos(x)*x^4-63*c[5]*sin(x)*x^3-123*c[5]*cos(x)*x^2-x*cos(x)*c[0]-22*x*cos(x)*c[4]+x*c[1]*sin(x)-5*x*c[3]*sin(x)+123*x*c[5]*sin(x))*(c[0]+c[1]*x+c[2]*(x^2+2)+c[3]*(x^3+x)+c[4]*(x^4-2)+c[5]*(x^5-3*x-x^3))

(9)

f := (8*x^3*(1/3)-2*x^(1/2))*y/GAMMA(1/2)+(1/1260)*x+k4

((8/3)*x^3-2*x^(1/2))*(c[0]+c[1]*x+c[2]*(x^2+2)+c[3]*(x^3+x)+c[4]*(x^4-2)+c[5]*(x^5-3*x-x^3))/Pi^(1/2)+(1/1260)*x+(x*c[0]+22*x*c[4]-c[1]*cos(x)*x^2-c[2]*cos(x)*x^3+2*c[2]*sin(x)*x^2-c[3]*cos(x)*x^4+3*c[3]*sin(x)*x^3+5*c[3]*cos(x)*x^2-c[4]*cos(x)*x^5+4*c[4]*sin(x)*x^4+12*c[4]*cos(x)*x^3-24*c[4]*sin(x)*x^2-c[5]*cos(x)*x^6+5*c[5]*sin(x)*x^5+21*c[5]*cos(x)*x^4-63*c[5]*sin(x)*x^3-123*c[5]*cos(x)*x^2-x*cos(x)*c[0]-22*x*cos(x)*c[4]+x*c[1]*sin(x)-5*x*c[3]*sin(x)+123*x*c[5]*sin(x))*(c[0]+c[1]*x+c[2]*(x^2+2)+c[3]*(x^3+x)+c[4]*(x^4-2)+c[5]*(x^5-3*x-x^3))

(10)

"f(x):=((8/3 x^3-2 sqrt(x)) (c[0]+c[1] x+c[2] (x^2+2)+c[3] (x^3+x)+c[4] (x^4-2)+c[5] (x^5-3 x-x^3)))/(sqrt(Pi))+1/1260 x+(x c[0]+22 x c[4]+x c[1] sin(x)-5 x c[3] sin(x)+123 x c[5] sin(x)-x cos(x) c[0]-22 x cos(x) c[4]-c[1] cos(x) x^2-c[2] cos(x) x^3+2 c[2] sin(x) x^2-c[3] cos(x) x^4+3 c[3] sin(x) x^3+5 c[3] cos(x) x^2-c[4] cos(x) x^5+4 c[4] sin(x) x^4+12 c[4] cos(x) x^3-24 c[4] sin(x) x^2-c[5] cos(x) x^6+5 c[5] sin(x) x^5+21 c[5] cos(x) x^4-63 c[5] sin(x) x^3-123 c[5] cos(x) x^2) (c[0]+c[1] x+c[2] (x^2+2)+c[3] (x^3+x)+c[4] (x^4-2)+c[5] (x^5-3 x-x^3))"

proc (x) options operator, arrow; ((8/3)*x^3-2*sqrt(x))*(c[0]+Typesetting:-delayDotProduct(c[1], x, true)+c[2]*(x^2+2)+c[3]*(x^3+x)+c[4]*(x^4-2)+c[5]*(x^5-3*x-x^3))/sqrt(Pi)+Typesetting:-delayDotProduct(1/1260, x, true)+(Typesetting:-delayDotProduct(x, c[0], true)+22*x*c[4]+Typesetting:-delayDotProduct(x, c[1], true)*sin(x)-5*x*c[3]*sin(x)+123*x*c[5]*sin(x)-Typesetting:-delayDotProduct(x, cos(x), true)*c[0]-22*x*cos(x)*c[4]-c[1]*cos(x)*x^2-c[2]*cos(x)*x^3+2*c[2]*sin(x)*x^2-c[3]*cos(x)*x^4+3*c[3]*sin(x)*x^3+5*c[3]*cos(x)*x^2-c[4]*cos(x)*x^5+4*c[4]*sin(x)*x^4+12*c[4]*cos(x)*x^3-24*c[4]*sin(x)*x^2-c[5]*cos(x)*x^6+5*c[5]*sin(x)*x^5+21*c[5]*cos(x)*x^4-63*c[5]*sin(x)*x^3-123*c[5]*cos(x)*x^2)*(c[0]+Typesetting:-delayDotProduct(c[1], x, true)+c[2]*(x^2+2)+c[3]*(x^3+x)+c[4]*(x^4-2)+c[5]*(x^5-3*x-x^3)) end proc

(11)

NULL

"H(f,alpha,x):=Int((x-s)^(alpha-1)*f(s)/GAMMA(alpha), s = 0 .. x)"

proc (f, alpha, x) options operator, arrow; Int((x-s)^(alpha-1)*f(s)/GAMMA(alpha), s = 0 .. x) end proc

(12)

`assuming`([value(%)], [x > 0])

proc (f, alpha, x) options operator, arrow; Int((x-s)^(alpha-1)*f(s)/GAMMA(alpha), s = 0 .. x) end proc

(13)

H(f, alpha, x)

Int((((8/3)*s^3-2*s^(1/2))*(c[0]+c[1]*s+c[2]*(s^2+2)+c[3]*(s^3+s)+c[4]*(s^4-2)+c[5]*(s^5-3*s-s^3))/Pi^(1/2)+(1/1260)*s+(s*c[0]+22*s*c[4]+c[1]*s*sin(s)-5*s*c[3]*sin(s)+123*s*c[5]*sin(s)-s*cos(s)*c[0]-22*s*cos(s)*c[4]-c[1]*cos(s)*s^2-c[2]*cos(s)*s^3+2*c[2]*sin(s)*s^2-c[3]*cos(s)*s^4+3*c[3]*sin(s)*s^3+5*c[3]*cos(s)*s^2-c[4]*cos(s)*s^5+4*c[4]*sin(s)*s^4+12*c[4]*cos(s)*s^3-24*c[4]*sin(s)*s^2-c[5]*cos(s)*s^6+5*c[5]*sin(s)*s^5+21*c[5]*cos(s)*s^4-63*c[5]*sin(s)*s^3-123*c[5]*cos(s)*s^2)*(c[0]+c[1]*s+c[2]*(s^2+2)+c[3]*(s^3+s)+c[4]*(s^4-2)+c[5]*(s^5-3*s-s^3)))/((x-s)^(1/2)*Pi^(1/2)), s = 0 .. x)

(14)

z := value(%)

int((((8/3)*s^3-2*s^(1/2))*(c[0]+c[1]*s+c[2]*(s^2+2)+c[3]*(s^3+s)+c[4]*(s^4-2)+c[5]*(s^5-3*s-s^3))/Pi^(1/2)+(1/1260)*s+(s*c[0]+22*s*c[4]+c[1]*s*sin(s)-5*s*c[3]*sin(s)+123*s*c[5]*sin(s)-s*cos(s)*c[0]-22*s*cos(s)*c[4]-c[1]*cos(s)*s^2-c[2]*cos(s)*s^3+2*c[2]*sin(s)*s^2-c[3]*cos(s)*s^4+3*c[3]*sin(s)*s^3+5*c[3]*cos(s)*s^2-c[4]*cos(s)*s^5+4*c[4]*sin(s)*s^4+12*c[4]*cos(s)*s^3-24*c[4]*sin(s)*s^2-c[5]*cos(s)*s^6+5*c[5]*sin(s)*s^5+21*c[5]*cos(s)*s^4-63*c[5]*sin(s)*s^3-123*c[5]*cos(s)*s^2)*(c[0]+c[1]*s+c[2]*(s^2+2)+c[3]*(s^3+s)+c[4]*(s^4-2)+c[5]*(s^5-3*s-s^3)))/((x-s)^(1/2)*Pi^(1/2)), s = 0 .. x)

(15)

`assuming`([value(%)], [x > 0])

int((((8/3)*s^3-2*s^(1/2))*(c[0]+c[1]*s+c[2]*(s^2+2)+c[3]*(s^3+s)+c[4]*(s^4-2)+c[5]*(s^5-3*s-s^3))/Pi^(1/2)+(1/1260)*s+(s*c[0]+22*s*c[4]+c[1]*s*sin(s)-5*s*c[3]*sin(s)+123*s*c[5]*sin(s)-s*cos(s)*c[0]-22*s*cos(s)*c[4]-c[1]*cos(s)*s^2-c[2]*cos(s)*s^3+2*c[2]*sin(s)*s^2-c[3]*cos(s)*s^4+3*c[3]*sin(s)*s^3+5*c[3]*cos(s)*s^2-c[4]*cos(s)*s^5+4*c[4]*sin(s)*s^4+12*c[4]*cos(s)*s^3-24*c[4]*sin(s)*s^2-c[5]*cos(s)*s^6+5*c[5]*sin(s)*s^5+21*c[5]*cos(s)*s^4-63*c[5]*sin(s)*s^3-123*c[5]*cos(s)*s^2)*(c[0]+c[1]*s+c[2]*(s^2+2)+c[3]*(s^3+s)+c[4]*(s^4-2)+c[5]*(s^5-3*s-s^3)))/((x-s)^(1/2)*Pi^(1/2)), s = 0 .. x)

(16)

``


Download proplem_in_maple.mw
 

hi

i have n  initial condition like x(0)=a0   ,x'(0)=a1       .....x(n-1)(0)=an-1  and also n equations like S[i]. i d like to write following code in maple

S[i]- ai-1  =0 for i=1,2,..,n

would you please help me how   should i  do it

thanks a lot

Hello again, it's my first time using maple, so I have more problems :(

I need solve three equations, but maple shows an error:

Error, (in solve) a constant is invalid as a variable, gamma

gamma.mw

I have used g instead of gamma and solve works, but I don't understand what happen.

 

The second problem is when I use g instead of gamma. In some tau values solve() doesn't show the solution. In each solve() always there are one unnecessary equation. Maybe could be that. But I don't know.

g.mw

 

Thank you in advance!!!

 

P.S. Sorry for my bad English

 Hello! I'm trying to solve the following: 

pde1 := (y+z)*(diff(u(x, y, z), x))+(z+x)*(diff(u(x, y, z), y))+(x+y)*(diff(u(x, y, z), z)) = 0;
{pdsolve(pde1,u(x,y,z))}

Unfortunately, after calling pdsolve , I get an empty result set . Can you help me figure out what's going on?  Does it  really have no solution? 

 

 

 

 

 

I try to give the plot, but it shows nothing. why? How can l find the range where 2+r*(b-2)*sqrt(b-1) can be positive, and the range where 2+r*(b-2)*sqrt(b-1) can be negative?


 

restart; with(plots, implicitplot); implicitplot(2+r*(b-2)*sqrt(b-1), b = 1 .. 100, r = 1 .. 100, scaling = constrained)

 

``

``


 

Download mm.mw

Hello Guys and Girls,

I have a problem with animate command with background option..

I attached my maple worksheet for your review.

Could you help me out?  Thanks.

I love Maple,

Sincerely

Ali Guzel

HI, 

I am using the series function on KummerU (Kummer function of the second kind). 

I found that series(KummerU(p,1/2,t),t) works as below, but series(KummerU(p,1/2,t),p) gives me the following error "Error in (series/fracpower) unable to compute series". 

Any idea what that is the case 

Thanks

series(KummerU(p, 1/2, t), t)

Could anyone give an example how to use the hint option in polynomial solutions in PDEtools in maple?

Hello, I have this:

maple.mw

I need save the three solutions in three different variables.

Thanks a lot!!!

I'm trying show the all roots of equations using Bairstow's methodt, but only shows the roots of Quadratic Factor and don't show the others roots of the other equation. Thanks

This the code:


 

restart; Bairstow := proc (n, a, u0, v0, itmax, TOL) local u, v, b, c, j, k, DetJ, du, dv, s1, s2; u := u0; v := v0; b := Array(0 .. n); c := Array(0 .. n); b[n] := a[n]; c[n] := 0; c[n-1] := a[n]; for j to itmax do b[n-1] := a[n-1]+u*b[n]; for k from n-2 by -1 to 0 do b[k] := a[k]+u*b[k+1]+v*b[k+2]; c[k] := b[k+1]+u*c[k+1]+v*c[k+2] end do; DetJ := c[0]*c[2]+(-1)*c[1]*c[1]; du := (-b[0]*c[2]+b[1]*c[1])/DetJ; dv := (b[0]*c[1]-b[1]*c[0])/DetJ; u := u+du; v := v+dv; printf("%3d %12.7f %12.7f %12.4g %12.4g\n", j, u, v, du, dv); if max(abs(du), abs(dv)) < TOL then break end if end do; printf("\nQ(x)=(%g)x^%d", b[n], n-2); for k from n-3 by -1 to 1 do printf(" + (%g)x^%d", b[k+2], k) end do; printf(" + (%g)\n", b[2]); printf("Remainder: %g(x-(%g))+(%g)\n", b[1], u, b[0]); printf("Quadratic Factor: x^2-(%g)x-(%g)\n", u, v); s1 := evalf((1/2)*u+(1/2)*sqrt(u*u+4*v)); if u^2+4*v < 0 then printf("Zeros: %.13g +-(%.13g)i\n", Re(s1), abs(Im(s1))) else s2 := evalf((1/2)*u-(1/2)*sqrt(u*u+4*v)); printf("Zeros: %.13g, %.13g\n", s1, s2) end if end proc; P := proc (x) options operator, arrow; x^5+(-1)*3.5*x^4+2.75*x^3+2.125*x^2+(-1)*3.875*x+1.25 end proc; n := degree(P(x)); a := Array(0 .. n); a[0] := P(0); for i to n do a[i] := coeff(P(x), x^i) end do; itmax := 10; TOL := 10^(-10); r := -1; s := -1; Bairstow(n, a, r, s, itmax, TOL)

  1   -0.6441699    0.1381090       0.3558        1.138
  2   -0.5111131    0.4697336       0.1331       0.3316
  3   -0.4996865    0.5002023      0.01143      0.03047
  4   -0.5000001    0.5000000   -0.0003136   -0.0002023
  5   -0.5000000    0.5000000    6.413e-08    9.268e-09
  6   -0.5000000    0.5000000            0            0

Q(x)=(1)x^3 + (-4)x^2 + (5.25)x^1 + (-2.5)
Remainder: 0(x-(-0.5))+(0)
Quadratic Factor: x^2-(-0.5)x-(0.5)
Zeros: 0.4999999993, -0.9999999997

 

 

Only show two roots: 0.4999999993, -0.9999999997, but the other roots are missing: 2, -1, 1+0.5i, 1-0.5i approximately, any solution?

I think it's in this part, but I can't think of how to implement it to get the missing roots.

 

Download Bairstow.mw

 

I'm using the 15 day trial as a Computer Science student. For my first project, Maple worked very well. I've been using the ApproximateInt() command. This command worked in the first assignment, and so I created a new document to start on my second assignment, and suddenly:

Entering the same ApproximateInt() command in a prompt line will not execute the command. Where it should display a plot of Riemann sums, it only displays the text I had entered. If I open the first document in which it was working properly, it also breaks upon re-iterating the command lines.

Image of expected behaviour:

Image taken right after pressing enter:

Is anyone familiar with this Maple behaviour? Thank you for any help. Meanwhile, I will attempt a reinstallation. The maple file is attached, as well.

P.S: Interestingly, the plot() command does work, as well as simple commands such as 1+2 (Displays "3")

my code is 
for i from 1 to 20 do:

print("new variable" + i)

end do;

It gives the result new vaiable + 1,

how can I print out new variable 1 instead of new variable + 1

The dsolve numeric events syntax requires the use of If(a,b,c) rather than the usual if then else syntax. Also, the possible action parts of an event are truly mysterious as are discrete variables. Has anyone plaed around with this much? For example, can the If's be nested? I know I can test that in a toy situation but there are many such questions that arise and I don't want to reinvent the wheel.

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