Re: simple pattern match question
- To: mathgroup at smc.vnet.net
- Subject: [mg91177] Re: [mg91151] simple pattern match question
- From: "Adriano Pascoletti" <adriano.pascoletti at gmail.com>
- Date: Fri, 8 Aug 2008 07:16:00 -0400 (EDT)
- References: <200808070842.EAA02148@smc.vnet.net>
Roger, the Mathematica help says that "Number represents an exact integer or an approximate real number in Read". Use NumericQ: In[1]:= f[(x_)?NumericQ] := x^2 In[2]:= f[3] Out[2]= 9 In[3]:= f[3.3] Out[3]= 10.889999999999999 If you are tempted to use NumberQ note that In[4]:= NumberQ[Pi] Out[4]= False In[5]:= NumericQ[Pi] Out[5]= True Adriano Pascoletti 2008/8/7 <congruentialuminaire at yahoo.com> > > 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 >
- References:
- simple pattern match question
- From: congruentialuminaire@yahoo.com
- simple pattern match question