MaplePrimes - answers and comments on Question, How to get a list of power of differential function expression

By degree

Markiyan Hirnyk — Thu, 10 Nov 2011 11:20:42 Z

How about this?
> restart; a := 6*F*u[0, x]*g[x, x]*g^2+24*F*u[0]*g[x]^3-18*F*u[0]*g[x]*g[x, x]*g+2*F*u[0]*g[x, x, x]*g^2:

>map(c ->degree(c, g), [op(a)]);

[2, 0, 1, 2]

Edit. PS and PPS were removed. The code was simplified.

Misoperation

Fei Wang — Sat, 12 Nov 2011 06:27:47 Z

I use MaplePrimes firstly. After uploading a file, I found the uploaded file maybe not work. So I deleted it and uploaded again.

Thanks for your direct and eager help to sovle my problem!!!

It is unfortunately that it does not work

Fei Wang — Thu, 10 Nov 2011 16:26:24 Z

It is unfortunately that it does not work and returned results is '[FAIL,FAIL,FAIL,FAIL,FAIL]'.

Proof

Markiyan Hirnyk — Thu, 10 Nov 2011 21:19:44 Z

@Fei Wang Goldy, can you present your worksheet in MaplePrimes?

Regard, MH

My results

Fei Wang — Fri, 11 Nov 2011 15:27:56 Z

Download file.mw

I has uploaded the file which shows the results what i said. Thank you for your patient answers!

Another situation

Markiyan Hirnyk — Fri, 11 Nov 2011 16:33:31 Z

@Fei Wang

First of all, my answer to your question is right. You try to apply this approach in another situation and obtain the output with FAIL. As far as I understand it, your syntax is not correct. The ?degree command is applicable only to variables in polynomials so the commands map(c-> degree(c, G[]), [op(S1)]) and map(c->degree(c, g(x, t)), [op(S1)]) are wrong.
Next, taking into account "g(x, t) will now be displayed as g", the command
> map(c-> degree(c, g), [op(S1)]);
[FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL, FAIL,
FAIL, FAIL, FAIL, FAIL, FAIL]
fails because S1 includes symbolic exponents in powers of g.
As yet the degree command operates only with integer exponents, but not with symbolic exponents:
> degree(g^3, g);

3
>degree(g^i,g)assuming i::posint;

FAIL