Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Hi !

This is my code :

and I don't know why I have this warning : Warning, The use of global variables in numerical ODE problems is deprecated, and will be removed in a future release. Use the 'parameters' argument instead (see ?dsolve,numeric,parameters)

and I can't plot my curve after :) If you guys have any ideas... thank you!


Hello everyone,

I am trying to solve a system of ODE's numerically but the problem is with the condition f(0)+g(0)=1.

Here is the system with the initial conditions,

ode1:=diff(f(x), x,x)+(f(x)+g(x))*diff(f(x),x)=0;
ode2:=diff(g(x), x,x)+(f(x)+g(x))*diff(g(x),x)=0;
ics:=f(0)+g(0)=1,D(f)(0) =0,D(g)(0) =1;

which give an error

Error, (in DEtools/convertsys) invalid specification of initial conditions

The above system is a simplified form of a very complicated one.


Hi Maple expert,

May I ask your time little bit, I am struggling with the 3D plot in maple, for basic 3D plot in maple is no problem for me, but this is a new case for me actually I want to perform a 3D plot based on these 3 different type of plots (or equations), here they are:

1. plot(2*(exp(-0.15*(u)^1.5))*(u)^0.5,u=0..2);

2. plot([0.2*(x-sin(x)),0.5*(1-cos(x)),x=0..10*Pi]);

3. polarplot(4+1*cos(5*x),x=0..2*Pi);

Can someone help me for this, many thanks for your help and time.> restart;
> l := 1; p := 1; A := .5; B := .5; pr := 1; n := [.5, 1, 1.5]; M := 0; b := .5; L := 0; s := .5; K := [blue, green];
                                [0.5, 1, 1.5]
                                [blue, green]

> for j to nops(n) do R1 := 2*n[j]/(n[j]+1); R2 := 2*p/(n[j]+1); R3 := 2/(n[j]+1);

sol1 := dsolve([diff(diff(diff(f(eta), eta), eta), eta)+f(eta)*(diff(diff(f(eta), eta), eta))+R1*(1-(diff(f(eta), eta))^2)-M*(diff(f(eta), eta)) = 0, diff(diff(theta(eta), eta), eta)+pr*f(eta)*(diff(theta(eta), eta))-R2*pr*(diff(f(eta), eta))*theta(eta)+R3*(A*(diff(f(eta), eta))+B*theta(eta)) = 0, f(0) = 1, (D(f))(0) = L+b*((D@@2)(f))(0), (D(f))(7) = 1, theta(0) = 1+s*(D(theta))(0), theta(7) = 0], numeric, method = bvp);

plots[odeplot](sol1, [eta, ((D@@2)(f))(eta)], color = red);

fplt[j] := plots[odeplot](sol1, [eta, diff(diff(f(eta), eta), eta)], color = K[j], axes = boxed); fplt[j] := plots[odeplot](sol1, [eta, f(eta)], color = K[j], axes = boxed);

tplt[j] := plots[odeplot](sol1, [[eta, theta(eta)]], color = K[j], axes = normal) end do;

plots:-display([seq(fplt[j], j = 1 .. nops(n))]);

plots:-display([seq(fplt[j], j = 1 .. nops(n))]);

plots:-display([seq(tplt[j], j = 1 .. nops(n))]);

Dear sir 

I am trying to plot the following link paper graphs for practice but I getting the plots for only one set of values here in this paper they plotted many so if you dont muned can help in this case. For example in this first graph named as Fig.1. please can you do this favour... and the paper link is


If I want to clear the screen what command I must use?

Thank you



I have a maple file (saved as a workbook) which is saved in dropbox and has been saved during progress.  However, when I open the last version in maple, it opens a version which looks like it is some of the first versions. I have tried following things without success:

* Restore previous versions from dropbox and open them in maple.  No matter which version I open, it shows the same two lines of text.  In dropbox I can see all previous versions and their file size which all are different and increasing in size over time as more was added to the file.

* send the file to another computer and open in maple on that computer


Does anybody have the answer to what I can do/what the problem is?




Hello every one,

I'm using Maple to create a compiled program of my model Maplesim. I had a error with "getcompiledProc" command, which is :

Error, (in GetCompiledProc) non-numeric initial condition for `Main.RAB.value`(t): Float(undefined)

the "Main.RAB.value(t)" represent a probe used to visualize an output of my system.

Does anybody had a such error ?
Thank you for your responses.


Hi I was wondering if theres a way to smoothen a signal in maplesim.
I was trying to create a simple moving average but it doesnt seem to be able to create a feed back loop?
Much appreciate any help, or if there are other ways within maplesim to do it.


I am writing a package to define a few Records and collect some quantities and formulae to do some arithmetic with.

At some point I started running into a severe problem: Each time I want to use one of the exports form the module, the Maple kernel dies with a "Stack limit exceeded" message. The issue is: This seems to happen only on Maple 2016. I had some issues in Maple 2015 but that got sorted by rewriting some stuff. I never had any issue like that with Maple 15. I went as far as commenting out most of my .mapleinit code to make sure that did not cause issues. The code works as intended in Maple 15 and in Maple 2015.

I am posting this here and am asking others to see if they can reproduce this. Needless to say I will SCR this. But I actually need to get this to work.

The error can be triggered by simply entering


after loading the package. Needless to say, it should just echo the name "Booster", to get more one would need to enter eval(Booster) (due to the last-name evaluation rules).



I solved two inequalities using

[solve]({f(theta) >0, f(theta) <=Pi}, theta)

for some complicated function f of theta, an solve gives me a list of intervals such as

[{theta <= Pi-arccos(-3/4+(1/4)*sqrt(13+16*sqrt(2))), arccos(3/4) < theta},

{arccos(-3/4+(1/4)*sqrt(13+16*sqrt(2)))+Pi <= theta, theta < 2*Pi-arccos(3/4)},

{theta <= 3*Pi-arccos(-3/4+(1/4)*sqrt(13+16*sqrt(2))), 2*Pi+arccos(3/4) < theta}]

I would like to convert each of the intervals to the range form a..b so I can plot the function over this range.

Is there a comand to convert something like {theta <=b, a < theta} to
a..b (assuming a and b are real numbers in some form)?  I can think of a rather complicated procedure to do it, but there should be something simpler.


I have computed the eigenfunction expansion for f(x)=x on 0<x<1 in terms of the eigenfunctions exp(-x/2)*sin(n*Pi*x).

I wish to calculate the weighted L2 error in this expansion (the weight function is w(x)=exp(x)).

Specifically, I want to determine how many terms in the eigenfunction expansion are necessary for the error to be less than say 0.3.

Here is the code:

f := x -> x
w := x -> exp(x)
assume('n', integer);
y :=  (n, x) -> exp(-x/2) sin(n Pi x)       
c := n-> (int(f(x)*y(n, x)*w(x), x = 0 .. 1))/(int(y(n, x)^2*w(x), x = 0 .. 1))
Fourierf := (n, x) -> sum(c(j)*y(j, x), j = 1 .. n)

fsolve(Lerror(n) = 0.3, n);

This seems to run forever without giving a value of n.  I know this is a large computation, but it seems that Maple should be able to handle it.  Does anyone have any suggestions?




Hello everybody,


I want to solve this pde.the desire solution is V(r,z). three boundar conditions are written that two of them are related to rhe radial and one is related to the longitudinal coordinate.

I attached the solution for you. but this solution is derived by Matlab. Now, I just want to resolve it by Maple, but I couldn't reach it. Please let me know the correct way asap.


Thanks a




Q := diff(V(r, z), r, r)+(diff(V(r, z), r))/r-V(r, z)/r^2+diff(V(r, z), z, z)+C/r = 0

diff(diff(V(r, z), r), r)+(diff(V(r, z), r))/r-V(r, z)/r^2+diff(diff(V(r, z), z), z)+C/r = 0





PDESolStruc(V(r, z) = _F1(r)*_F2(z)-(1/2)*(_C1/r+_C2*r+_C3*r*ln(r))*C/_C3, [{diff(diff(_F1(r), r), r) = _F1(r)*_c[1]+(-(diff(_F1(r), r))*r+_F1(r))/r^2, diff(diff(_F2(z), z), z) = -_F2(z)*_c[1]}])












For remainder of division of a (multivariable) polynomial to several polynomials at a same time one can use NormalForm in Maple. It is easy to write a procedure to also show the division but I wonder if there is any determined command such as NormalForm for this aim?


do anybody know, how I can see how a function is programmed? I want to know more about dsolve function and what is hidden behind.

Thank you all

Hej all,

I have a problem. When i have a 9-1 vector "DD" how can i get maple to solve DD^2 my equation is A=(pi/4)*DD^2 should be simple.


Also when i have two vectors one is 9-1 and the other is 5-1 i want to divide the 5-1 / 9-1 but i want all possible soluitons? not just 5 results but 45 results.(the zip fuction only gives me 5 results)


Pls help 


Kind regards

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