indeterminate and infinity expressions
- To: mathgroup at smc.vnet.net
- Subject: [mg67564] indeterminate and infinity expressions
- From: Søren Merser <merser at image.dk>
- Date: Sat, 1 Jul 2006 05:11:38 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi
I need to evaluate the expression below:
In[1]:= Log[(#/yhat)] + (1-#) Log[(1-#)/(1-yhat)] & /@ {0,1} /. yhat->123
Out[1]= {Indeterminate, -Infinity}
Depending on the value of #, I get Infinity and Inderterminate results.
To get the wanted answer I've to split the expression into two parts
In[2]:= ans1 = # Log[#/yhat] & /@ {0, 1} yhat -> .123
Out[2]= {Indeterminate, 2.09557}
In[3]:= ans2 = (1-#) Log[(1-#)/(1-yhat)] & /@ {0, 1} /. yhat -> .123
Out[3]= {0.131248, Indeterminate}
In[4]:= Max[#] & /@ ({ans1, ans2} /. Indeterminate -> 0)
Out[4]= {2.09557, 0.131248}
Now, is there an easier way to do it?
Regards Soren