How do I make functional substitutions?

daniel.e2718
111 ●5 ●9 ●17

I want to substitute one function for another. Consider this:

v = function('x')
u(x) = (v(x)+v(-x))/2
delta = 10^(-90)
u(delta).subs(v=gamma(x))

The very last line is what I'm trying to accomplish. I know it's the wrong command, but I'm wanting to make the substitution $v(x)\to\Gamma(x)$.

Is there a way along these lines to do such a functional substitution?

1 Answer

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Eviatar Bach
748 ●15 ●37 ●52

I think you want v = function('v') for the first line; the first argument is the name of the function.

Here's the full code:

v = function('v')
u(x) = (v(x) + v(-x))/2
delta = 10^(-90)
u(delta).substitute_function(v, gamma)

I'm puzzled as to why it doesn't work if v is defined as v = function('v', x). Anyone know?

*Exactly* what I was looking for! Thanks! EDIT: Good question though. Why doesn't it work if you specify the variable of the function?

daniel.e2718 ( 2012-10-22 17:26:34 +0200 )edit

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Asked: 2012-10-22 16:16:35 +0200

Seen: 356 times

Last updated: Oct 22 '12