Maple Questions and Posts

These are Posts and Questions associated with the product, Maple

Is there a command or method in Maple to list all initially protected names?

This page list undocumented protected names, and this page  lists initially known names, which I assume are all protected.

But what about a list of all protected names? sin,cos, eval, uneval, etc.. any name that can't be assigned to. In my search so far, I could not find how to find these names. There are 100's of such names. Can one get them all in a list to look at?

Using Maple 2019.1

I want to solve the following system using PDE Solve command but finding an error. Please help me in this regard. Thanks!


restart; d1 := 1; d2 := 1; AA := 0.2e-2; BB := 0.79e-1; L := 1;
with(PDEtools, casesplit, declare);
PDE1 := diff(u(x, t), t) = d1*(diff(u(x, t), x, x))-u(x, t)*v(x, t)^2+AA*(1-u(x, t)); PDE2 := diff(v(x, t), t) = d1*(diff(v(x, t), x, x))+u(x, t)*v(x, t)^2-BB*v(x, t);
                      /  2         \                           
         d            | d          |                  2        
PDE1 := --- u(x, t) = |---- u(x, t)| - u(x, t) v(x, t)  + 0.002
         dt           |   2        |                           
                      \ dx         /                           

   - 0.002 u(x, t)
                          /  2         \                   
             d            | d          |                  2
    PDE2 := --- v(x, t) = |---- v(x, t)| + u(x, t) v(x, t) 
             dt           |   2        |                   
                          \ dx         /                   

       - 0.079 v(x, t)
IBC1 := {u(0, t) = 1, u(1, t) = 1, u(x, 0) = 1-(1/2)*sin(Pi*(x-L)/(2*L))^100}; IBC2 := {v(0, t) = 0, v(1, t) = 0, v(x, 0) = (1/4)*sin(Pi*(x-L)/(2*L))^100}; dys1 := {IBC1, IBC2, PDE1, PDE2};
         /              /  2         \                           
         | d            | d          |                  2        
dys1 := < --- u(x, t) = |---- u(x, t)| - u(x, t) v(x, t)  + 0.002
         | dt           |   2        |                           
         \              \ dx         /                           

   - 0.002 u(x, t), 

                /  2         \                                     
   d            | d          |                  2                  
  --- v(x, t) = |---- v(x, t)| + u(x, t) v(x, t)  - 0.079 v(x, t), 
   dt           |   2        |                                     
                \ dx         /                                     

   /                                                           100
   |                                        1    /1           \   
  < u(0, t) = 1, u(1, t) = 1, u(x, 0) = 1 - - sin|- Pi (x - 1)|   
   |                                        2    \2           /   


   /                                                       100\ 
   |                                    1    /1           \   | 
  < v(0, t) = 0, v(1, t) = 0, v(x, 0) = - sin|- Pi (x - 1)|    >
   |                                    4    \2           /   | 
   \                                                          / 

pds := pdsolve(dys1, numeric, time = t, range = 0 .. 1);
Error, (in pdsolve) invalid input: `pdsolve/numeric` expects its 2nd argument, IBCs, to be of type {list, set}, but received time = t
p1 := pds:-plot(t = 0, numpoints = 50);

p2 := pds:-plot(t = 1/8, numpoints = 50, color = blue);

p3 := pds:-plot(t = 1/4, numpoints = 50, color = green);

plots[display]({p1, p2, p3});
Error, `pds` does not evaluate to a module
Error, `pds` does not evaluate to a module
Error, `pds` does not evaluate to a module
Error, (in plots:-display) expecting plot structures but received: {p1, p2, p3}

Hi, Is there a way in which i can solve the following optimal control problem numerically with Maple ??

where P(t)=N(t)+S(t)+A(t) and N(0)=0.4897, S(0)=0.4018, A(0)=0.1085.

μ=0.000833, d=0.000666, ε1=0.0020, ε2=0.000634, β1=0.002453, β2=0.25*0.02, γ1=0.0048, γ2=0.25*0.02+0.00013, k1=1, k2=0.001, k3=0.99.


p1,p2,p3 are transversality conditions 


Answers and advice are very appreciated. 

Thank you all for reading.


Hi MaplePrimes team,


If I assume a plot-based function or procedure C(s,t) and P1(t) are hidden in a package somewhere I don’t care about the type of geometry (spacecurve or plot3d). Now, I just want to animate P1(t) following the variable t. How do I do?

Example 1: Curve Animation in variable t

1. Equation

C := (s,t)-> Vector([cos(s), sin(s), t*s/2]):     #Helix shape as example


2. Plot

P1 := t-> display(spacecurve(C(s,t), s = 0..3*2*Pi, linestyle = solid)):



Example 2: Surface Animation in variable t

1. Equation

S := (x,y,t)-> Vector([x, y, t/(1 + x^2 + y^2)]):

2. Plot

P2 := t-> display(plot3d(S(x,y,t), x = -2..2, y = -2..2)):


If I assume the function or procedure S(x,y,t) and P2(t) are hidden in a package somewhere I don’t care. Now, I just want to animate P2(t) following the variable t. How do I do?



Example 3: Mixing Curve and Surface Animation in variable t

The ideal/”dream” basic syntax would be:

animate(display, [P1(t), P2(t)], t = t1..t2)

But it does not work.




hi everybody:

I have two Maple files that file file is a package and file is based on the file when running the file I see the error and don't know how to solve it, I attach these files, thank you for helping me.

Could someone confirm if this is a problem in this sample application?

In 2019, in the folder 

    C:\Program Files\Maple 2019\samples\ProgrammingGuide\RandomnessTests

There is sample application. Opening the main module file RandomnessTests.mpl  and scrolling down a little bit to the include statements show

$include ""
$include ""
$include ""
$include ""
$include ""
$include ""

$include ""
$include ""

However, in the same folder, there is no file. There is only Data.mpl file.

So how could this sample application work?  

This sample app have more problems. The file  say

Data := module()
option package;

And the file Data.mpl has

Data := module()

This is all so confusing. Seems someone made some typos and not tested this app? Why put a sample application which makes learning packages in Maple more confusing?

ps. I did not yet try to figure how to locad it and run it myself, I was just browsing it.



I have the following expression

I would like to know if is it possible avoid negative exponent goes to denominator when I use expand().

Thank you!







Hi. I want to take Laplace transform from differential equation with the final condition(tf).   If the differential equations have initial conditions  it appears in Laplace (for example laplace transform of diff(u,t) is U-s*u(0) that u(0) is initial condition)but for final conditions or boundry conditions What to do ?my equation is



[addtable, fourier, fouriercos, fouriersin, hankel, hilbert, invfourier, invhilbert, invlaplace, invmellin, laplace, mellin, savetable]



u is function of x,t and u(x(10),10)=0

u[1] := (1/2)*x^2*t; L1 := laplace(eq1, t, s)





u(x(10),10)=0; desired output u[1]=x^2(t-10)/2

s1 := u[1]; N[1] := (1/2)*(diff(s1, x))^2+x*(diff(s1, x)); ul[2] := laplace(N[1], t, s); u[2] := invlaplace(ul[2]/s, s, t)









I want to apply: u[2](x(10),10)=0





Hello. I am building a graph and specify the axis titles. The 'y' label is to the left of the axis. Is it possible to move it somehow? I want to put it above the axle (in this case it was over 100)

plot(ff(x), x = 0 .. 10, color = black, labelfont = [TIMES, 19], thickness = 1, size = [1200, 600], axes = boxed, linestyle = 5, labels = ['x', 'y'], axis = [gridlines = [20, color = black]])

Maple always starts a new document with a 2D input style and Times New Roman font. How to change the boot style? (default).

whats wrong with the codes while running the codes in maple 13 it will take memory and time as 41.80M, 9.29s while the same code is running in maple 18 it will take 1492.38M , 911.79s

Why the same codes take different time and memory. The codes are here



Gr:=0.2: Nb:=0.1:Nt:=0.3:B:=1:B1:=0.7:m:=1:k:=0.1:
h:=z->piecewise( z<=d1,    1,
                 z<=d1+L1,   1-(gamma1/(2*Ro))*(1 + cos(2*(Pi/L1)*(z - d1 - L1/2))), 
                        z<=B1-L2/2,  1 ,          
                    z<=B1,  1-(gamma2/(2*Ro))*(1 + cos(2*(Pi/L2)*(z - B1))),
                 z<=B1+L2/2,  R1-(gamma2/(2*Ro))*(1 + cos(2*(Pi/L2)*(z - B1))),
                 z<=B,    R1):


     legend = [gamma2 = 0.0,gamma2 = 0.02,gamma2 = 0.04],
     linestyle = [solid,dash,dot],
     color = [black,black,black],
     gridlines=false, axes=boxed);


     legend = [gamma2 = 0.0,gamma2 = 0.02,gamma2 = 0.04],
     linestyle = [solid,dash,dot],
     color = [black,black,black],
     gridlines=false, axes=boxed);


why do solve and fsolve have different results?

I have to solve the equation rH''(r)+H'(r)+(rk^2-r^2*b^2/R^2)=0 where k, b, and R are real constant positive number, with condition H(R)=0 and H(1/R)=R to be solved into series of power. I know from the literature that xy''+y'+xy=0, can't be solved in terms of elementary function(see G.Nagy-ODE-November 29, 2017) that's why I'm interested in an approximate solution based on series, or any results as long as it satisfied the too condition H(R)=0 and H(1/R)=R of the real function H(r). 

Please advice!.

I want to find one option of coodiantes of vertices A, B, C of the triangle ABC, knowing that coordinates centre of circumcircle is O(0,0) and length of sides are 3, 5, 7. 
How can I get the result?

    I have encountered a peculiar behavior in Maple 2019 worksheets. I have attached a worksheet which illustrates a reversal of the coefficient and the blade in the following types of expression.  My Maple installation is set in options to use maple input and output (1D notation).  I am using build ID 1399874.

The procedure I was testing used the add function to expand a multivector over basis blades and coefficients represented by indexed names; for example
    add(a[indx[]]*e[indx[]], indx = indxes); where indxes:={[1],[2],[3],[1,2],[1,3],[1,4],[2,3],[2,4]};

The expected result
a[1]*e[1]+a[2]*e[2]+a[3]*e[3]+a[4]*e[1, 2]+a[5]*e[1, 3]+a[6]*e[1, 4]+a[7]*e[2, 3]+a[8]*e[2, 4] in 1D notation but instead I got

e[1]*xx[1]+e[2]*xx[2]+e[3]*xx[3]+e[1, 2]*xx[4]+e[1, 3]*xx[5]+e[1, 4]*xx[6]+ e[2, 3]*xx[7]+e[2, 4]*xx[8]

(Note and the different coefficient names illustrates the exchange is caused by sorting.)

Initially, I assumed that this resulted from the add command, but after I directly entered an indexed expression into the worksheet and obtained a similar result I realized it must be occurring during the output.  Apparently, before the expression is written, it is first sorted. I know this because, if the coefficient is named a,b,c,d ( less than e), the expression is not exchanged. In addition, if I convert the expression to 2D output, the expression is written in the normal order specified in the add command.

I also confirmed this behavior in Maple 2018.2 as well.  Hopefully, the example worksheet attached will illustrate this behavior.  Am I correct in assuming that when the code I am using in the worksheet with is incorporated into a module in an mpl file and loaded, this will not be an issue.

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