On Jan 24, 9:29 am, Mike Witt <[email protected]> wrote: > To give the 'partial' notation rather than 'D' notation. > I hope that makes sense. The idea is that I'd like something on > the order of "\frac{\partial}{\partial y} foo" ... > > Anyway, I can't find the information about this now, and I wonder > if someone could point me to the relevant documentation or thread.
This was discussed before in: http://groups.google.ca/group/sage-support/browse_thread/thread/d7520e53b492f878/0dfb76b4d21dbb47 The problem arises when you want to print: D[0](f)(g(x,y),h(x,y)) In this situation, the "first variable" for f does not have a natural name, so it is hard to come up with a sensible "partial derivative" print form. Earlier threads already pointed out that even cases like D[0](f)(x,h(x,y)) do not equal the simplistic guess (df/dx)(x,h(x,y)). The chain rule really is the culprit here. The form (df/du1)(u1,u2)|_{\{u1=x,u2=h(x,y)\}} would be a possibility and could be done with some default choice for the variable name (here u). The code could then develop further by adding heuristics for choosing more sensible variable names and situations where the "evaluated at" clause can be collapsed. -- 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/sage-support URL: http://www.sagemath.org
