I'm trying to do some manipulation of expressions that contain products of scalars and non-commuting operators (as defined by the physics package). The worksheet below shows this on a particular example. I can imagine a long/tedious way to do this, but perhaps the two key steps outlined below might be easily handled by some pattern-matching maple trickery, that is obvious to the pros here? 

In short, I need to convert expressions of the general form:

to something like:

expr3:=alpha*f([Sx,Sz, Sz]) + beta*f([Sy,Sz]) + gamma*f([Sz, Sy, Sx]) + f([Sx]) + beta^2;

... with the caveat that the 'Sk' are operators (and their products could be of an arbitrary length).

The context here (for those who care) is basically to use the nice handling of non-commutative algebra of the Physics package to write down some Heisenberg equations of motion for a given system, and then approximate those using a cummulant expansion (this is in practice really tedious to do by hand in even simple systems, but arguably the most painful part is trivially done by the physics' package nice handling and sorting of the non commuting oprators). That, in essence requires one to transform larger products of non-commuting operators into smaller products (so say approximating an expectation value of 3-operator product as a sum of 2-operator peoducts and single operators). 

If anyone has ideas how best to approach this in the maple-ish way, please let me know.

thanks!

Download cumulant.mw

Hello, 

Im having trouble fully opening the contents of my maple file. Only half of the doucment is showing up.

I get the following message: "There were problems during the loading process, Your worksheet may be incomplete."

There is also no bak. file available. 

Can anyone please help?

matOpgaver_1.mw.zip

sys_ode.mw 

sys := -diff(g(x), x)*e^(c*x)*c/(3*t) + f(x) = 0, t*(c*e^(2*c*x)*diff(g(x), x) + t*e^(c*x)*(2*c^2 + 3*f(x) - 1))*diff(f(x), x) + 6*c^2*(diff(f(x), x, x)*t*e^(2*c*x) + diff(f(x), x, x, x)*e^(3*c*x)/3) = 0. I have attached worksheet. Please solve this system,of ODE.

I was wondering if anyone had a solution for this issue, everytime I try to export my work as a .pdf file the program freezes up and I have to shut it off using task manager.

I have Maple 2020 installed in addition to Maple-Gym.

So Maple 2019 seems to be unable to evaluate a relatively easy integeral for a positive integer, but when the obvious substitution u=cos(x) is made it is able to evaluate the integral.  Is there some setting I am using that is causing Maple to give up without much effort?  
 

Download walter.mw

Suppose you have some functions like:

S^1 --> S^1: w(x,y) = (x^2 - y^2, 2xy)

Then this is equivalent of

w(exp(i 2Pi t)) = exp(i 4 Pi t)

Or if I have S^1 --> S^1: w(x,y) = (-y,x), we would get:

w(exp(i 2Pi t)) = exp(i 2 Pi (t+1/4))

How can I obtain the second form of the expression in Maple given the first one?

hello,

so i'm trying to compute the determinant of a Matrix(7*7) to obtain a single equation ( dispersion equation ) that i need to use for further investigation.

But unfortunately for a certain value Bi=1(i need this value ) i get 0.it would be nice if some can help me 

Determinant.mw

I want a procedure that has arguments f(function) N (natural number)  and an array of values a0,...an is what is returned 
So far I have this 
restart
Chebyshev_approx:= (f::procedure , N :: numeric);
local F,n,a;
for n from 0 to N do 
if n=0
then a:=1/Pi*evalf(Int(1/sqrt(1-x^2)*f(x),x=-1..1)
else a:=2/Pi*evalf(Int(1/sqrt(1-x^2)*f(x)*ChebyshevT(n , x),x=-1..1)
fi;
F:=F+a*ChebyshevT( n , x)
od;
F
end;


I have plain text files with comma delimited fields. Some fileds are strings and some are numeric.

When importing the file using

data:=Import(file_name,format="CSV",output=Matrix);

Maple changes any field which is string but contains a number inside it, as in "1"  to number 1 

And this causes all sorts of problems for me when processing the matrix data, since the program expects some fields to be strings. 

I looked at all options, but do not see how to tell Maple to keep a string as string, even if what is inside it is a number.

Here is an example file  "t.txt"

1,2,"0",4
1,2,"1",4
1,2,"A",4

I read it as follows

restart;
file_name:="C:/TMP/t.txt";
data:=Import(file_name,format="CSV",output=Matrix);

And Maple returns 

You see it changed "0" to 0 and "1" to 1.

This might be how CSV is supposed to work?. Does Maple have any option to override this default behavior in order to keep strings as strings, even though there is a number inside the string. I'll try to see if there is another format other than CSV to try which might behave better.

Maple 2021 on windows 10.

I've noticed after a creating a few documents that when save such documents as PDFs on my Mac, the drawing elements in my drawings are misalgined. Is this just a bug or is there a way to prevent this?  I've attached screenshots of the correct drawign in a document and what the result is in a pdf.

Dear maple users

A fine day wishes to all 

In my problem, L(z) is a piecewise condition.

L(z):

I have to calculate the f(x,t) value at x=0.71,t=1.12 and z=0.71 for L(z)=0..1.

How to calculate the f(x,t) value.JVB1.mw
 

Download JVB1.mw

I am brand new to Maple, both as a specific program and as an example of symbolic mathematical software (although years ago I spent some time with MathCad).

I am interested in referrals to online resources which can help me progress down the learning curve. I have a substantial background in application computer programming, mostly in C#.

So if there's such a thing as "Maple for Programmers" that might be ideal...particularly since I find Maple's syntax and semantics to be "just similar enough" to coding that it causes me a lot of frustration. As in, simply entering the examples from the online manual Just Doesn't Work :).

Thanx!

- Mark

Is there a reason why maple can't directly integrate over iterable objects (lists, vectors, matrices, etc.)?
From a first glance I would think doing 

int(<sin(x), cos(x)>, x=0..2)

should be equivalent to:

map(int, <sin(x), cos(x)>, x=0..2)

Is there a good reason why this would be a bad idea?  (for whatever it's worth, that's what mathematica does by default).

Dear Maple community,

I'm trying to calculate a Steady State Vector of the attached matrix using this Maple routine, but, unfortunately, don't get any solution even after a 30 min calculation on a 64Gb machine. Am I doing something wrong and, if so, could you please give me a hand how to conduct this calculation? Thanks!

Maple_SteadyStateVector.mw

Hello all,

at the beginning of my document I need to assign a value to my variable, for example 0.4, so I can calculate a number of material pararamters for this exact value. At the end I want to include a plot that demonstrates the material behaviour for the variable ranging from 0 to 1. 

However, I have found that I can not plot a graph if I have assigned a value to that variable before. The "unassign" command sadly does not work. 

I am a beginner in Maple so i am probably missing something obvious, but I would appreciate any help.

Thank you!