Comment #38 on issue 1816 by brad.froehle: Adding partial derivatives and
taking derivatives with respect to functions
http://code.google.com/p/sympy/issues/detail?id=1816
I'm really uncomfortable with this, for example:
x = symbols('x')
diff(1-cos(x)**2,sin(x))
0
diff(simplify(1-cos(x)**2),sin(x))
sin(x)
The explanation in comment 32 is spot on and matches well with the
mathematical theory behind the Euler-Lagrange equations (and not the sloppy
and and often confusing presentation given in most physics texts).
--
You received this message because you are subscribed to the Google Groups
"sympy-issues" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to
[email protected].
For more options, visit this group at
http://groups.google.com/group/sympy-issues?hl=en.
