Maple 2020 Questions and Posts

These are Posts and Questions associated with the product, Maple 2020

My worksheet has suddenly begun producing the following error message when executing legitimate commands:

Error, (in cos) type `SymbolicInfinity` does not exist

Why has this worksheet suddenly begun issuing these mysterious error messages and how can it be restored to working order?

The uploaded worksheet is intended to be an example of the Equal Incircles Theorem, but the incircles displayed are not equal.

What is wrong in the worksheet and how can the error(s) be corrected?

I am particularly interested in a full coordplot3d display for ellipsoidal coords. 


Why maple can not compute integral?



A padel group organises doubles tournaments with the following structure: 16 players participate in four rounds, with each round consisting of four doubles matches. Players switch partners after each round.

So what I require is some code to generate the first round matches, the second round, the third, the nth .....

note the worksheet I bastardised from Tom Leslie's work.

This post is to help anyone who is just as frustrated about typesetting in plots
as I was before I solved my problem. (Note: the technique works with the version

2020 and newer and may work with earlier versions.)


Why? Because there is no obvious help in Maple showing what works. (And if folks

can improve what I have posted,  please do so. At least when someone executes

a search for this type of problem, they might see the best approach.)

Goal: typeset a name of a function in any text of a plot.

Approach: According to help, '?plot, typesetting',  one should use the
option(procedure?) typeset.   For example:

"restart;   plots:-setoptions(size = [400, 200]):    `f__1`(x) :=cos(x)*(e)^(-(x^(2))/(4)) :    p1 := plot(`f__1`(x), x = -5..5,                         legend = typeset("function ", `f__1`(x) )  );"



However, what I want in the legend is the expression "`f__1`(x),"not the evaluated

expression. Entering the name with single quotes around the expression leads to this:


p1 := plot(f__1(x), x = -5 .. 5, legend = typeset("function ", 'f__1(x)'))



which is great, except that when I wish to redisplay the plot




the expression f__1(x)is evaluated.


According to the code completion capability of Maple, the procedure

"Typesetting:-Typeset" exists, and it does not evaluate the function:


p1 := plot(f__1(x), x = -5 .. 5, legend = Typesetting:-Typeset(f__1(x))); plots:-display(p1)



except there is no help regarding this procedure.


It appears that the procedure operates only on one item.


Solution: Hence, the ultimate solution for my problem is to still use the typeset 

option, but Typeset any expression.


p1 := plot(f__1(x), x = -5 .. 5, legend = typeset("function ", Typesetting:-Typeset(f__1(x)))); plots:-display(p1)



Again, if you can contribute to this post, I would appreciate it.




I have plotted psi [1] and psi [2] by using contourplot, but I want to show streamline or Flow nets on curves psi[1] and psi[2].

please help me obtain updated graphs like the attached figure.



How I can show that the value of psi 1 through method #1 is equal to that one in method #2?

is possible to verify by analytic results, not using and placing parameter's numerical values?


why in eq1 some parameters such as beta 1, Q110,... are not placed (They defined before eq1 !!!!)


I'm running Maple 2020 on a Mac with OS 14.3.1.  Maple is not seeing current files in folders, and when it saves files, it does so with an older date.  In Settings, Maple has permission to access the Desktop, Documents, and Downloads folders, the only options that my Mac provides.

It's a bit frustrating.  Any help would be appreciated.


I am working on a 2-dimensional real curve gamma, that is being deformed by a real 2x2 matrix A and translated by some shift vector s. Both the matrix A and the vector s depend on two real parameters alpha and beta, which vary between 0 and 1. My goal is to create an animated plot that shows the curve depending on the parameters alpha and beta (ideally with some sort of slider, so I can play with different values of alpha and beta). I am having a hard time animating this, also because I am unsure if this is actually possible in Maple. The code I am working with is so far:

f := x -> exp(2*I*Pi*x);
CDFT := Matrix(3, 3, [[1, 1, 1], [1, f(1/3), f(2/3)], [1, f(2/3), f(1/3)]]);

al := 10/100;
be := 10/100;
lam1 := f(al);
lam2 := f(be);
lam3 := f(-al - be);
coef := (1/3*HermitianTranspose(CDFT)) . (Vector[column](3, [lam3, lam2, lam1]));
a := coef[1];
b := coef[2];
c := coef[3];

gam := t -> MatrixVectorMultiply(Matrix(2, 2, [[Re(a^2 + b*c), -Im(a^2 - b*c)], [Im(a^2 + b*c), Re(a^2 - b*c)]]), Vector[column](2, [cos(2*t) - 2*cos(t), sin(2*t) + 2*sin(t)])) + 3*Vector[column](2, [Re(b*c), Im(b*c)]);
P1 := plot([cos(2*t) - 2*cos(t), sin(2*t) + 2*sin(t), t = 0 .. 2*Pi], color = [blue]);
P2 := plot([gam(t)[1], gam(t)[2], t = 0 .. 2*Pi], color = [purple]);
plots:-display([P1, P2]);

Note that you can basically ignore everything up to the definition of the curve gam (short for gamma), apart from the definition of the parameters al and be (alpha and beta). The plot P1 corresponds to the "unperturbed curve", i.e. when we multiply the curve by the identity, which happens for alpha=beta=0. The plot P2 is now the deformed curve. The output is then:

My goal is now to animate this plot such that I can play with different values of alpha and beta, without having to manually insert them. How do I do this?

This worksheet animates the motion of an object (say, a cube which slides frictionlessly) on a rotating carousel. The cube is not self-propelled.

How can the worksheet be modified to handle the combination of the carousel motivated motion and the cube's own generated motion, caused by, say, by a few strategically placed thrusters?

The cube's own generated path could be a straight line, or a curve such as an ellipse. The cube's own motion could have a constant velocity or be accelerating.

Maple seems to give me very inaccurate results for this computation, I'm wondering if this is a known issue and if there's a way to fix it? Worksheet:

Exact commands I ran:
B := (n, i, p) -> binomial(n, i)*(p^i)*(1-p)^(n-i)/i;


This outputs 0, when it should output 1/2. See image attached:


Is there a fix for this?

this is my model. Please give me how to find the DFE and basic reproduction number from maple.

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