RE: how to pull real numbers out of a linear funktion ?
- To: mathgroup@smc.vnet.net
- Subject: [mg11147] RE: [mg11092] how to pull real numbers out of a linear funktion ?
- From: "Barthelet, Luc" <lucb@ea.com>
- Date: Mon, 23 Feb 1998 21:41:05 -0500
you might want to try something like this. f[c_Real, x_] := c f[x] ; f[c_Integer, x_] := c f[x] ; f[c_ /;(Im[c]!=0),x_] := -c f[x]; I then got: f[3,4] 3 f[4] f[3+5I,5] (-3-5 I) f[5] Good Luck! Luc Barthelet >-----Original Message----- >From: Roland Bollmann [SMTP:roland@arnold.fkp.physik.th-darmstadt.de] To: mathgroup@smc.vnet.net >Sent: Sunday, February 22, 1998 11:55 AM >To: mathgroup@smc.vnet.net >Subject: [mg11092] how to pull real numbers out of a linear funktion ? > >I want to define a function f[x_] with the property, that > >f[c_ x_] := c f[x] whenever c is a real number > >and > >f[c_ x_] := -c f[x] whenever c is a komplex number. > >It semms to me, that mathematica can not give a variable the attribute >"real number" or "complex number". > >But it should be easy ... somehow ;-) > >Roland Bollmann (student of physics) >