Well, I didn't try this particular integral in Mathematica. If Mathematica gives the correct answer - that would mean that the theory is OK.

Alec

Well, I didn't try this particular integral in Mathematica. If Mathematica gives the correct answer - that would mean that the theory is OK.

Alec

Originally, using MeijerG for definite integration seemed like a good idea, but then it had appeared that it was implemented in Maple mostly in one direction - converting functions and integrals to MeijerG. The conversion in the opposite direction, from MeijerG to elementary functions and expressions seems to be not working in many cases.

Alec

Originally, using MeijerG for definite integration seemed like a good idea, but then it had appeared that it was implemented in Maple mostly in one direction - converting functions and integrals to MeijerG. The conversion in the opposite direction, from MeijerG to elementary functions and expressions seems to be not working in many cases.

Alec

Well, I am not saying that it looks good - I was just stunned that it worked at all!

Alec

Well, I am not saying that it looks good - I was just stunned that it worked at all!

Alec

Just wait for 3-4 days and somebody will reply. I didn't want to say what I was thinking about that because I wanted to see a reply from one of the developers.

Alec

Just wait for 3-4 days and somebody will reply. I didn't want to say what I was thinking about that because I wanted to see a reply from one of the developers.

Alec

I just tried Paulina's suggestion for using more than one parameter, and it worked,

f := (x::integer, NULL)-> x+1:

f(3);

                                      4

Alec

I just tried Paulina's suggestion for using more than one parameter, and it worked,

f := (x::integer, NULL)-> x+1:

f(3);

                                      4

Alec

Functions are treated differently in collect. In particular, your last example didn't go through `collect/series` (as it was in the first example). If it did, it would also return an error, just a different one,

series(u[t],u);
Error, invalid expression for series

series(u(t),u);
Error, (in series/function) improper op or subscript selector

By the way, the following also works OK,

collect( u()*(u[t]+1), [u(), u[t]], distributed);

                            u() + u[t] u()

The following gives the correct answer in the original example,

alias(u[t]=f());
                                 u[t]

collect( u*(u[t]+1), [u, u[t]], distributed);

                              u + u[t] u

Alias would work OK even without functions though,

alias(u[t]=f);
                                 u[t]

collect( u*(u[t]+1), [u, u[t]], distributed);

                              u + u[t] u

Alec

Functions are treated differently in collect. In particular, your last example didn't go through `collect/series` (as it was in the first example). If it did, it would also return an error, just a different one,

series(u[t],u);
Error, invalid expression for series

series(u(t),u);
Error, (in series/function) improper op or subscript selector

By the way, the following also works OK,

collect( u()*(u[t]+1), [u(), u[t]], distributed);

                            u() + u[t] u()

The following gives the correct answer in the original example,

alias(u[t]=f());
                                 u[t]

collect( u*(u[t]+1), [u, u[t]], distributed);

                              u + u[t] u

Alias would work OK even without functions though,

alias(u[t]=f);
                                 u[t]

collect( u*(u[t]+1), [u, u[t]], distributed);

                              u + u[t] u

Alec

Exactly!

At the beginning (2 weeks ago), I tried to make rst working thinking that it would be much better (because I used to it), but yesterday I upgraded MoinMoin to version 1.7 and Python to version 2.5, installed docutils, so that rst is available, and today both Alejandro Jakubi and me played with it - and I already started to think that wiki format is more convenient :)

Alec

Try to type it (in standard math mode, i.e. after Ctrl+R, for example) instead of copying and pasting. Copying and pasting, by the way, worked OK for me, too (in Maple 12). If that doesn't work, one might try to use `\xB1` (with backticks) instead of \xB1.

Alec

Multiplication sign usually works OK. I did the quadratic formula as an example (above). The example with  y = \xB1 x works only because Maple inserts the multiplication sign itself - select the formula, click on it and look at the formula in the toolbar. That works the same, say, for y = x z.

Alec