Re: Defining derivatives
- To: mathgroup at smc.vnet.net
- Subject: [mg87868] Re: [mg87851] Defining derivatives
- From: Carl Woll <carlw at wolfram.com>
- Date: Sat, 19 Apr 2008 03:32:41 -0400 (EDT)
- References: <200804181111.HAA18885@smc.vnet.net>
dh wrote: >Hello All, > >does anybody know how to define symbolic derivatives. E.g.: > >f[x_]:=f1[x]; > >f'[x_]:=f2[x]; > > Use Derivative[1][f] = f2 Carl Woll Wolfram Research >this does not work because f on the lefthand side is evaluated. To > >prevent this (do not forget to remove f before redefining it): > >f[x_]:=f1[x]; > >HoldPattern[f'[x_]]:=f2[x]; > >this gives no message, but f'[x] returns f1[x] instead of f2[x]. > >The same thinhg happens when you change the sequence of definitions: > >f'[x_]:=f2[x]; > >f[x_]:=f1[x]; > >Further, where is the information about derivatives stored? > >thank's a lot, Daniel > > > >
- References:
- Defining derivatives
- From: dh <dh@metrohm.ch>
- Defining derivatives