Re: How build a ?TestFuntion that applied to a list gives only the elements that are function of x

*To*: mathgroup at smc.vnet.net*Subject*: [mg33030] Re: [mg32995] How build a ?TestFuntion that applied to a list gives only the elements that are function of x*From*: Omega Consulting <omega_consulting at yahoo.com>*Date*: Tue, 26 Feb 2002 04:35:25 -0500 (EST)*Sender*: owner-wri-mathgroup at wolfram.com

At 01:38 AM 2/23/2002, J. Guillermo Sanchez wrote: >How build a ?TestFuntion that applied to a list give only the elements >that are function of x > >Example: > >In[]:= {Sin[a x], b x, t, c r}/.?TestFuntion > >gives > >Out[] = {Sin[a x], b x} > >Thanks > >Guillermo Sanchez TestFuntion[expr_] := !FreeQ[expr, x] Then Select[{Sin[a x], b x, t, c r}, TestFuntion] or Cases[{Sin[a x], b x, t, c r}, _?TestFuntion] -------------------------------------------------------------- Omega Consulting "The final answer to your Mathematica needs" Spend less time searching and more time finding. http://www.wz.com/internet/Mathematica.html