Hi, 

Versions concerned:  [ Maple 2015 ... Maple 2018 ]

I use DocumentTools:-Tabulate to display a matrix of numbers while coloring them according to some condition.
(line DocumentTools:-Tabulate(M, color=((M,i,j)->`if`(M[i,j]>3,....) below ... please note the output is not loaded for some unknown reason).
The fact is that the matrix appears with black characters meaning 'color' doesn't work.

In a second attempt I convert matrix M into a matrix of strings and use now
DocumentTools:-Tabulate(S, color=((S,i,j)->`if`(parse(S[i,j])>3,...)
I get now the desired result with some blue and red numbers.

So converting to strings could be a workaround.
But think to matrices where elements would be algebraic expressions, for instance 
M := Matrix(2, 2, (i,j)->exp(x^i)+cos(x*j))
and that we use the coloring scheme is color=((M,i,j)->`if`(i+j>3, "Red", "Blue")
Converting M to a string matrix will display the element [2, 2] in red and the others in blue, but what you get then is a no longer a 2D pretty output but, literally, things like exp(x^2)+cos(x*2) 

The "convert to string" workaround is thus far from perfect.
Is the fact that 'color' only acts on strings a "normal and known" behaviour?
Is it possible to change the color of the font for non "string type matrices" ?
 

Download Tabulate_Color.mw

Draw the coordinate grid of the elliptical coordinate system.

Get an animation of the transformation of an ellipse into a hyperbola.

Dear all,

I am totally new to maple and would like to get an understanding for the "language" and how to work with maple. Thats why I tried to get a simple model from Mathematica into Maple, however, unfortunately, I am not able to initialize the plot I want to generate. Hence, I am wondering if someone could please help me here. My code looks as follows:
 

P[t] := a*ED[t - 1] + P[t - 1]

ED[t] := DC[t] + DF[t];

DC[t] := c(P[t] - P[t - 1])

DF[t] := b(F - P[t])

my initial conditions are:

a := 1
c := 0.75
b := 0.2
F := 100
P[0] := F
P[1] := F + 1

Now I would like to see how P[t] develops for t from 0 to 100, but I get the error "Error, (in Plot) Plot([ED[t-1]+P[t-1], t = 0 .. 100]) is not a valid command; see the plot help page" However, I am not able to get a grip on the helppage information. Hence I would be very glad if someone could help me here please.

Thank you in advance!

Best, Alex

what's the easiest way to have maple simplify the expression below from 'expr1' to the form of 'desired_form'? mathematica automatically simplifies to that (subjectively of course!) much nicer looking form.

Download factor_under_sqrt.mw

how can i get an 'implicit=false' form (no RootOf) of my eigenvalues from the Eigenvectors() command? Should one expect the behavior be the same in Eigenvectors() and Eigenvalues()?

thanks

Download evals.mw

The help for the package Differential Geometry suggests one way to create an anholonomic frame, but the method suggested assumes one knows the frame and can write it in the coordinates of the manifold, and use this representation to compute the structure equations. It is useful to turn this problem around: suppose I know the structure equations but I do not know the frame, how do I correctly enter this in Maple so that later computations are correct?

Here is an example:

with(DifferentialGeometry): with(LieAlgebras):
DGsetup([x, y], R2):          
Fr := [A, B]; StructureEquations := [[A, B] = a(x, y)*A];
LD := LieAlgebras:-LieAlgebraData(StructureEquations, Fr, M);
DGsetup(LD, verbose):

that creates the Lie algebra M. I thought it would produce the manifold M whose frame {e1,e2} (or {A,B})) obeys the structure equations. But it does not. Indeed, the simple example

LieBracket(e1, f(x, y)*e2);

returns

f(x,y) a(x,y) e1.

The extra term where e1 differentiates f(x,y) does not appear. Just to be clear, the correct answer is

f(x,y) a(x,y) e1 + e1[f] e2.

How should I correctly setup this manifold?

Should Maple handle this error internally and may be give no solution if it can't solve it instead of this  error?

When setting boundary condition to zero, maple gives error below. Heat PDE in a sphere. No angle dependency. Only the radial part.

unassign('r,u,t');
pde:=diff(u(r,t),t)= 1/r*diff(r*u(r,t),r$2); #Laplacian in spherical
ic:=u(r,0)=1;
bc := u(1,t) =0;
pdsolve([pde,ic,bc],u(r,t),HINT =boundedseries(r=0)) assuming t>0

Error, (in assuming) when calling 'ln'. Received: 'when calling 'ln'. Received: 'numeric exception: division by zero''

Adding assumptions such as 0<r,r<1 did not help.

Physics version 348. Maple 2019 on windows 10. Is there something I am doing wrong? 

The following code yields "false" for the trace being non-negative.  This, however, is incorrect.

A look at the final expression for the trace shows it is a sum of products of positive values.

Does anyone know what the problem is?

restart;

with(LinearAlgebra);

n := 3;

p := 2;

Y := Matrix(n, p, symbol = y);

W := Matrix(n, n, symbol = w, shape = symmetric);

for i from 1 to n do

for j from 1 to n do

assume(w[i, j], RealRange(0, 1))

end do:

end do:

d := DiagonalMatrix(W . Matrix(n, 1, 1))

is(simplify(Trace(simplify(Transpose(Y) . (d-W) . Y))) >= 0)

Maple has powerful tools to manager styles of its documents. Similar to word processors, it is possible to set up font and paragraph options. Unfortunately, the styles of Help System, as I understand, are completely unchangeable. Meanwhile, it makes sense to improve the view of Help pages. Say, Help’s hyperlinks are pale and unpleasant  for eyes. Maybe, are there some hidden options for changing Help styles?

Hi!

Maple returns typographic the functions applied in a definition, which hardens the reading. Can anybody hint me on what to do to change this setting? Also symbolic variables are not being calculated:

All the best,

Why does Maple display eval(diff(f(r),r),r=C)=0;  differently when C is a number?

unassign('f,C,r');
eval(diff(f(r),r),r=C)=0;
eval(diff(f(r),r),r=5)=0;

I wanted the first one to display the same as the second one. First one looks confusing. it looks like taking derivative w.r.t to C. Is there a way to make the first one look like:

Hi,

I am having issues with switching from math mode to text mode, when it comes to adding a new line of text under a line of math mode, without evaluating the math. In a previous version of Maple (not sure witch one, probably Maple 2018), I would switch from math mode to text mode by using the shortcut "command + T", followed by hitting the "->" button on the keyboard and then hit enter to start a new line in text mode. But this does not work in the latest version of maple. Does anyone have a solution for this problem?

Also, is there a way to remove the "toolbox" (i.e. "solve for"/"expand"/"simplify"/"isolate"/etc.), so it only appears when right-clicking on the expression you want to edit?

It's no secret that I liked the older versions of Maple, but I'd very much appreciate some assistance with the 2019 version!

Kind regards,

Lisa

Hi Experts

The following code

with(plottools);
P := plot3d(cos(x)*cos(y), x = -Pi .. Pi, y = -Pi .. Pi);
exportplot("./test.eps", P, "eps");

results in a very different exported image, depending on if it is executed from a .mw file or a .mpl. How can I get the .mpl export to look like the .mw export?

Details: I understand that .mpl might require adding axes=boxed, but especially the orientation is very odd. It doesn't even orient it like the ASCII plot.

Hi Maple Expert,

c*(r-1)*exp(x*beta)/((1+varphi*exp(x*beta))*(-varphi*exp(x*beta)*r+varphi*exp(x*beta)+1))

c = exp(exp(x*beta)*(r-1)/(1+varphi*exp(x*beta)))

with

ln(r) = varphi*exp(x*beta)*(r-1)/(1+varphi*exp(x*beta))-1

Please help me, and thank you in advance.

Regards,

Sarni