As discussed in http://www.mapleprimes.com/questions/144586-Op-Command-Isnt-Working-As-Expected , the indices change some time at run time so previously working command is not working for me.

I am trying to use 

eq3 := applyop( u->Parts( u, phi[i](y) ), { 1,10,13,20 }, eq2 );

which clearly use the 'op' to get operands from eq2, but since the indices change at every run or on some run, the code is useless. The problem is...

Attached is my sheet. Please have a look.  my_scrach_Sheet.mw

Have a look at the last command of the sheet.

I am trying to extract integrals from the equaions(eq10_1, for example) using 'op', but it isn't working as expected, is it a bug or I am doing something wrong?

Second question: 

I am not been able to do sorting for all these equations, any suggestions?

I have a Matrix 'A' in maple with symbolic entries and I need to use that Matrix in matlab M file. The symbols with in 'A' are already initialized in M file.

How is this possible?

For Matrices 'A' of small dimension, I can use the codegeneration package to convert 'A' to Matlab Matrix and then copy paste.

But for matrices of 1000x1000, lets say, does not seem as a option.

Here is my sheet. non_linear_P2_last_q.mw

In this problem I have achieved every thing what I aimed, thnaks to the wonderful people here!!!

I am looking for a way to do it in a more structured way meaning the calculation of Jacobian in the attached sheet is somewhat manuel, though I wonder does maple has some other way?

I have a situation

restart:
with(IntegrationTools):
with(PDEtools):
declare(w(r));
assume(delta::constant, R::constant, K:: constant, U::constant):

ODE_1:=diff(w(r),r)+R*(diff(w(r), r))^3-K/r;

declare(u(r));
ODE_T_1:=collect(algsubs(w(r)=u(r)+(r-1)*(U-0)/(delta-1), ODE_1),diff(u(r), r)) ;

eq1:=int(phi[i](r)*ODE_T_1,r=1..delta) assuming delta > 1;

eq2:=Expand(eq1);

eq3 := applyop(u->Parts(u,phi[i...