@Preben Alsholm 

The post is just a simple example.

I want that i is shown (print(i)) at the same time the for command is executing.

This is to know at what iterator the for command is during the calculation.

Assume for example we have a procedure that take 15 minutes and the i must vary from 1 to 20

for i from 1 to 20 do x[i]:=f_proc(i); print(i); end do:

I want to know with print(i) the stage of calculation at same time of calculation

I do'nt know if it's clear

@JohnS 

Thank you.

Yes it is a good idea that Maple define my local variables.

Thank you for the answer.

I solved the problem when changing e1 as

e1:=seq(map(evalf,s1), j=1..Qr):

Thank you for the response.

I will think on the two propositions.

I have many local variables.

@Carl Love 

I understand the diffivulty.

Thank you

@rlopez 

Thank you for the answer

I want to use MatrixFunction for BesselY(A,B) ?

Is it possible or not ?

@Adri van der Meer 

Thank you for the answer

But

MatrixFunction(A, sin(x), x); is not the same as sin~(A) ?

I understand that we can not use MatrixFunction for BesselY(A,B) ?

@acer 

Yes, it is less time and memory consuming to use Eignevectors(V) and apply sqrt to the result than using MatrixPower. Thank you.

I corrected also the repetition in matrix inversion.

But, I should give high Digits for large value for N in this case also to get accurate results.

I will also investigate the position of the command Digits in the code.

When you have time, please give me other ideas to improve the computation.

Best regards

Kamel

@Kitonum 

Maple 18 gives the same error. 

Maple 15 gives the solution with no problem.

@Alejandro Jakubi 

Yes, I think the two environnements are differents (Maple and Matlab).

I use generally Maple for symbolic calculations (I appreciat it) and Matlab for numerical calculations. From the answers, I think it is simple to continue to do that.

I wanted to do all my calculations by Maple.

Thank you

@acer Thank you acer

Yes, it is what I want. It work well.

Thank you again

@Kitonum Thank you

But, I am interesting in the polar plot as given in:

R:=5:

freq:=4:

plots:-display(plot(R,theta=0..2*Pi,color=blue,coords=polar),plot(R+cos(freq*theta),theta=0..2*Pi,color=red,coords=polar),gridlines=false,scaling=constrained);

Now, I do not know if it is possible to correct the axis as explained in my above post.

@acer 

When we plot(cos(theta),theta=0..2*Pi), theta vary from 0 to 2*Pi in the X axis and cos(theta) vary from -1 to 1 in the Y axis.

When we plot the function cos(theta) with polar coordinates as:

R:=5:

freq:=5:
plots:-display(plot(R,theta=0..2*Pi,color=blue,coords=polar),plot(R+cos(freq*theta),theta=0..2*Pi,color=red,coords=polar),gridlines=false,scaling=constrained);

The X axis and Y axis varies from -6 to 6. These axis represent the function R+cos(theta).

Is it possible to remove theses axis which correspond to R+cos(theta) and replace them with new axis X and Y where origines are at the radius R.

From the polar plot, I want to get in the figure, 0 replaced by -3, 2 by -2 and 4 by -1, to get the variation of cos(theta) between -1 and 1.

I hope it is clear now.

@acer 

Is it possible to get on the axis of ordinate only the magnetude of the function cos(theta) and not R+cos(theta) ?

Thank you

@Carl Love 

Yes, this is what I want

Thank you