Unanswered Questions

This page lists MaplePrimes questions that have not yet received an answer

Hello guys.
I want to solve Laplace's equation for a triangle plate, subject to the following boundary conditions:

For the contour y = x, u(x,y) =20

For the contour y = -x+2, u(x,y) =100




Hi maple users 

I am working with the PDE solver.

i am receiving a following error

"unable to compute solution for t>HFloat(0.0):" 

Kindly do the needful how to rectify this error.


HHow do i correct "error, illegal use of an object as a name"

Dear maple user i am facing difficulty to plot the graph   for different values  of parameter M=2,4  and fixing t=j=0 to 2 and   y=i=0 to 4 on x axis and U on y axis. I am unable to plot 2D . I am enclosing the codes and sample graphs. 

# Parameter values:
 Pr:=0.71:E:=1:A:=0:Sc:=0.02: K:=1:

a := 0: b := 1: N := 9:
h := (b-a)/(N+1): k := (b-a)/(N+1):

 lambda:= 1/h^2:  lambda1:= 1/k^2:
# Initial conditions
for i from 0 to N do 
  U[i, 0] := h*i+1:
end do:

for i from 0 to N do 
  T[i, 0] := h*i+1:
end do:
for i from 0 to N do 
  C[i, 0] := h*i+1:
end do:

# Boundary conditions
for j from 0 to N+1 do 
  U[0, j] := exp(A*j*lambda); 
  U[N+1, j] := 0;
  T[0, j] := j*lambda1; 
  T[N+1, j] := 0;
  C[0, j] := j*lambda1; 
  C[N+1, j] := 0 
end do:

#Discretization Scheme
for i to N do 
  for j from 0 to N do 
    eq1[i, j]:= lambda1*(U[i, j+1]-U[i, j]) = (Gr/2)*(T[i, j+1]+T[i,j])+(Gr/2)*(C[i, j+1]+C[i,j])+(lambda^2/2)*(U[i-1,j+1]-2*U[i,j+1]+U[i+1,j+1]+U[i-1,j]-2*U[i,j]+U[i+1,j])-(M/2)*(U[i,j+1]+U[i,j]) ;
    eq2[i, j]:= lambda1*(T[i, j+1]-T[i, j]) = (1/Pr)*(lambda^2/2)*(T[i,j+1]-2*T[i,j+1]+T[i+1,j+1]+T[i-1,j]-2*T[i,j]+T[i+1,j])+(E*lambda^2)*((U[i+1,j]-U[i,j])^2);
    eq3[i, j]:= lambda1*(C[i, j+1]-C[i, j]) = (1/Sc)*(lambda^2/2)*(C[i,j+1]-2*C[i,j+1]+C[i+1,j+1]+C[i-1,j]-2*C[i,j]+C[i+1,j])+(K/2)*((C[i,j+1]+C[i,j]))  
  end do
end do:

# Determine the unknowns in the system
  `union`(  seq(seq( indets( eq1[i,j], name), i=1..N), j=0..N),
            seq(seq( indets( eq2[i,j], name), i=1..N), j=0..N),
            seq(seq( indets( eq3[i,j], name), i=1..N), j=0..N)
# And how many unknowns
# And the number of equations

# So if one supplies values for 'Gr' and 'M', and
# (assuming the equations are consistent), one ought
# to be able to get values for C[1..9, 1..10],
# T[1..9,1..10], and U[1..9,1..10]
# As an example below, choos Gr=1.0 and M=2, then the
# following obtains a 'solution` afer a minute or so
  fsolve( eval( [ seq(seq(eq1[i,j], i=1..N),j=0..N),
                  seq(seq(eq2[i,j], i=1..N),j=0..N),
                  seq(seq(eq3[i,j], i=1..N),j=0..N)
                [Gr=1.0, M=2]




Hi got this set of error using the Plot package. Anyone here know what they mean? 

Maple offers the dimension “lenght” whereas MapleSim offers two types.

What is the difference between the two types length and distance?

Can they always be used interchangeably?

Hello community. I'm trying to use Maple for some study.
My goal is to get the Wiener-Hopf equation in matrix form like in the book (eq 3.56).
So at first i need the gradient of eq 3.53, the result is eq 3.55 (nabla is not printed) .
Could you please provide an example of this operation, if it is possible, thanks.

During my reaserch on diffusion I am arrived at the integral with argument

exp(-1/sqrt(x^2 + 1)) which Maple is not able to solve.

If some experts in solving integrals is able to solve it please keep me informed.

The file in Maple 2022 is below


Hello everyone!

I use this procedure to open my inbox:

ShellExecute := define_external('ShellExecuteA', hwnd::(integer[4]), lpOperation::string, lpFile::string, lpParameters::string, lpDirectory::string, nShowCmd::integer[4], 'RETURN'::integer[4], LIB = "C:\\WINDOWS\\SYSTEM32\\shell32.dll"):
OpenBrowser := proc(someURL::string := "http://")

ShellExecute(0, " ", someURL, " ", " ", 1); NULL;

end proc:

Case 1:  I entered the correct email address of my friend who sent me the mail


As a result, the content of the message I received was opened with full information.

Case 2:  When I enter an arbitrary email address that is not my friend, the result is that no content is displayed.


On the email there is only the message: The conversation you requested could not be loaded.

May I ask:  Is there any Maple command to return true in case 1 and to return false in case 2 ?

Thank you very much for your help !

When I try to change the number format (decimal places) of a sequence in Maple Flow using the right hand slide out context panel all numbers in the sequence are replaced by only the first number in the sequence.  I'm not sure if it has been fixed in 2022.1

Before the adjustment ...  

Selecting fixed prompts the result to stop after the first number in the series.