## 489 Reputation

10 years, 240 days

## a good idea...

Thank you.

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

## Thank you...

I solved the problem when changing e1 as

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

## Warning...

Thank you for the response.

I will think on the two propositions.

I have many local variables.

## thanks...

I understand the diffivulty.

Thank you

## I want to use MatrixFunction for BesselY...

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

Is it possible or not ?

## BesselY~(A,B) the same as MatrixFunction...

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) ?

## Digits...

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 e...

Maple 18 gives the same error.

Maple 15 gives the solution with no problem.

## You are right...

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

## Yes, it is what I want...

@acer Thank you acer

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

Thank you again

## Polar plot...

@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.

## Axis in polar plot...

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.

## Magnetude of the function...

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

## Thank you...

Yes, this is what I want

Thank you

## Yes, you are right as always...

Yes your first code do the work (sorry). I have not understand the effect of the frequency.

I am very happy, thank you

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