Re: simple pattern match question

*To*: mathgroup at smc.vnet.net*Subject*: [mg91165] Re: simple pattern match question*From*: "David Park" <djmpark at comcast.net>*Date*: Fri, 8 Aug 2008 07:13:33 -0400 (EDT)*References*: <g7ed78$2po$1@smc.vnet.net>

Just a small error in syntax. What you want is: f[x_?NumberQ] := x^2 f[3] 9 f[3.3] 10.89 -- David Park djmpark at comcast.net http://home.comcast.net/~djmpark/ <congruentialuminaire at yahoo.com> wrote in message news:g7ed78$2po$1 at smc.vnet.net... > Hello UG: > > I am trying to understand simple pattern rule evaulation. The > following trivial examples baffles me: > > --------------------------------------------------- > In[1]:= f[x_Number] := x ^ 2 > In[2]:= f[3] > Out[2]= f[3] > > In[3]:= f[3.3] > Out[3]= f[3.3] > > In[4]:= NumberQ[3.3] > Out[4]= True > -------------------------------------------------- > Why is it that f[3.3] does not evaluate?? > > TIA. > > Regards..RogerW >