I want sage to implicitly differentiate a function for me, say
d/dx f(x)^2 = 2f(x)* f'(x).
I can do this by entering:
var('x')
f=function('f', x)
(f^2).diff(x)
This returns
2 f(x) D[0] (f) (x)
which is correct, but hard for me to read. Can I make sage return:
2 f(x) f'(x)
Thanks.
You can try the patch attached to issue #6344. It is more than 3 years old, so some work might be needed to make it apply to a recent Sage version, but it essentially does exactly what you need. See this comment for some examples.
This is easy to read:
sage: maxima('diff(f(x)^2,x)')
2*f(x)*'diff(f(x),x,1)
And
sage: from sympy import *
sage: x=Symbol('x')
sage: f=Function('f')
sage: diff(f(x)^2,x)
2*f(x)*Derivative(f(x), x)
Also:
sage: maxima_console()
(%i1) derivabbrev:true;
(%o1) true
(%i2) diff(f(x)^2,x);
(%o2) 2 f(x) f(x)
x
Asked: 2012-11-26 00:19:07 +0200
Seen: 425 times
Last updated: Nov 26 '12
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