RE: simple problem with Map?!?

*To*: mathgroup at smc.vnet.net*Subject*: [mg49485] RE: [mg49480] simple problem with Map?!?*From*: "Florian Jaccard" <florian.jaccard at eiaj.ch>*Date*: Thu, 22 Jul 2004 02:44:49 -0400 (EDT)*Reply-to*: <florian.jaccard at eiaj.ch>*Sender*: owner-wri-mathgroup at wolfram.com

Plus@@# evalautes the sum of a single element of d0... so #/Plus@@# always gives 1 ! You must write : pppp = N[# / (Plus @@ d0)] & /@ d0 regards F.Jaccard -----Message d'origine----- De : Relishguy [mailto:relishguy at pluggedin.org] Envoyé : mer., 21. juillet 2004 12:41 À : mathgroup at smc.vnet.net Objet : [mg49480] simple problem with Map?!? I do not understand why the last evaluation ends up screwed: In[1]:= d0 = {30,60,180,60,30}; In[2]:= tt = Plus @@ d0 Out[2]= 360 In[3]:= pp = N[d0 / tt] Out[3]= {0.0833333,0.166667,0.5,0.166667,0.0833333} In[4]:= ppp = N[d0 / (Plus @@ d0)] Out[4]= {0.0833333,0.166667,0.5,0.166667,0.0833333} In[5]:= pppp = N[# / (Plus @@ #)]& /@ d0 Out[5]= {1.,1.,1.,1.,1.} Can anyone explain this simply? Do I need Hold[] or Evaluate[] somewhere? TIA. Regards..