Re: eval differential expressions
- To: mathgroup at yoda.physics.unc.edu
- Subject: Re: eval differential expressions
- From: rubin at msu.edu (Paul A. Rubin)
- Date: Mon, 20 Jun 94 12:39:42 EDT
>Is there an easy way to evaluate differential expressions for various
>functions?
>For example, if I have D[f[x],x]^2+f[x] in Mma, I'd like to evaluate it for
>various functions f[x]. This can be done via naming the expression and
>then letting f[x_]=<desired fn of x> and typing the expressions name
>upon which its evaluated - but this seems awfully clumbsy!
>
>Any suggestions?
>Thanks.
>
>
Two possibilities:
1. Make your expression an operator (on f):
g[ f_ ] := D[f[x], x]^2 + f[x]
g[ <your function here> ] or g /@ { <list of your functions here> }
2. Name your expression and then use the replacement operator to substitute
other functions for f:
g = D[f[x], x]^2 + f[x] (* f as yet unspecified *)
g /. {f -> <your function here>}
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