I agree with you that the names are fairly expressive. But, sleepy me, I had not thought about comparing them with the content of Tools -> Options. Thanks.

I agree with you that the names are fairly expressive. But, sleepy me, I had not thought about comparing them with the content of Tools -> Options. Thanks.

I have never tinkered with that file, only with my own maple.ini file. Is there some documentation on the various properties of that file?

I have never tinkered with that file, only with my own maple.ini file. Is there some documentation on the various properties of that file?

Thanks, Israel and Acer.

It is certainly not the first time that I have had difficulties with these scoping issues, and, I am afraid, it will probably not be the last time. However, to minimize the risk of the latter I will bookmark your posts.

A beautiful analysis.

I think that you are absolutely right, thanks for your link.

Your cut-down version produces a plot in Maple 9.5.

I am pleasantly surprised by your interest in my plots which, being some time ago now, I had almost completely forgotten.

The code was written in Maple 9.5, where it works: I have just copy-pasted the code and run it in both Maple 9.5 and Maple 11. I have no Maple 8 version so I am not able to verify your problem. Hopefully someone else (maybe Scott at MapleSoft) can help you out.

As in your original code you define M1, M2, and M3 as

M1 := (u,v) -> N[1](u,v);
M2 := (u,v) -> N[2](u,v);
M3 := (u,v) -> N[3](u,v);

which is problematic. I did not comment on it then, though, because I thought it would only obscure things. But inserting values (u,v) = (s,t), say, brings out the problem:

M1(s,t);
M2(s,t);
M3(s,t);
              sin(v)(s, t) - cos(v)(s, t) u(s, t)
              -sin(v)(s, t) u(s, t) - cos(v)(s, t)
                     2                       2        
         cos(v)(s, t)  u(s, t) + sin(v)(s, t)  u(s, t)

One might think (at least, that was what I did yesterday) that the following might work:

M1 := (u,v) -> N[1];
M2 := (u,v) -> N[2];
M3 := (u,v) -> N[3];

But it does not as the following clearly shows (no proper dependence on s and t):

M1(s,t);
M2(s,t);
M3(s,t);
                       sin(v) - cos(v) u
                       -sin(v) u - cos(v)
                           2           2  
                     cos(v)  u + sin(v)  u

This is usually where the unapply business becomes murky to me: these latter definitions of M1, M2, and M3 seem like functional operators (which is what unapply produces), so why do they not work?

Interesting. What could be the reason for the Chinese politics? Censorship, or what?

I agree with you that there is no need to have images stored externally. Thanks for reminding me about the File Manager in the new editor. I think that I have kept on using the old way of doing things, i.e., using My files under Navigation. But, of course, it is much faster to use the now present File Manager. I guess, old habits die slowly.

It is one of those functions that I am not yet completely sure of myself how or when to use. I am quite certain that others here at mapleprimes can give far better explanations.

But after having identified in your code what seemed to be the problem area, I knew from experience that unapply might solve the problem. According to its help page unapply turns an expression into a functional operator. An example, closely related to your code:

N := u + v:
M_old := (u,v) -> N;
M_new := unapply(N,u,v);
M_old(s,t);
M_new(s,t);
                      M_old := (u, v) -> N
                    M_new := (u, v) -> u + v
                             u + v
                             s + t

Note that the parantheses used in my previous post are superfluous.

Thanks for setting the course. Now it is up to me to set sail.

Thanks for setting the course. Now it is up to me to set sail.

It seems to work if you define M1, M2, and M3 as follows:

M1 := unapply(N[1],(u,v));
M2 := unapply(N[2],(u,v));
M3 := unapply(N[3],(u,v));