Re: Parameter conditions
- To: mathgroup at smc.vnet.net
- Subject: [mg88667] Re: Parameter conditions
- From: David Bailey <dave at Remove_Thisdbailey.co.uk>
- Date: Mon, 12 May 2008 04:45:28 -0400 (EDT)
- References: <g07gt8$8ro$1@smc.vnet.net>
Steven Siew wrote: > I'm just curious why the simple code below is not working. > > Why is happy[4] not returning the number 200 > > > In[1]:= happy[p_?PrimeQ] = 100; > happy[p_?Not[PrimeQ]] = 200; > > In[3]:= Inhappy[4] > Out[3]:= happy[4] > > In[4]:= happy[5] > Out[4]:= 100 > The pattern p_?Not[PrimeQ] is wrong - try using p_/;Not[PrintQ[p]] David Bailey http://www.dbaileyconsultancy.co.uk