I have an expression of the following structure (the real case is much more complicate but this will illustrate):

expr:=(a+q)*A+b*q*B;

I am looking for a way to change only the first occurrence of q. In my specific case, q << a so I can approximate that instance of q with 0. This I cannot do for the second occurrence of q. Note that the trivial subs(a+q=a) does not work for my real case as a is too complicated (meaning that while in principle I can do it, it looks extremely messy and in any case would not be general).

I can probably concoct something using op(#,expr) and has, but I am wondering whether there is an easier and faster way.

TIA,

Mac Dude

An indefinite integral cancels out one differentiation:

int(diff(w(s),s,s),s)=diff(w(s),s);

But for a definite integral Maple does not recognize that:

int(diff(w(s),s,s),s=0..L) = int(diff(w(s),s,s),s=0..L);

What I would have expected is something like:

int(diff(w(s),s,s),s=0..L) = eval(diff(w(s),s),s=L)-eval(diff(w(s),s),s=0);

I cannot get Maple to recognize this even when assuming real or positive.

What I am really after is this: w(s...

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Speed is becoming an issue. I dearly would like to run some of the integrations (which is where the time is spent) in parallel. The contributions from different coils would trivially parallelize,...

Hi,

I am trying to define a system of units so that I get results in the units I want.

Specifically; I want to use energy in MeV (or eV, if I have to) and masses*c^2 in MeV (or eV) as well. Related, I need ScientificConstants like Planck's h in MeVs etc.

So I say

AddSystem('Accelerator','MeV','meter','second');
UseSystem('Accelerator');

which is accepted. I even get energies converted to MeV if I enter one in a different unit and use

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By poking...