Re: Variant of inner Product ...

*To*: mathgroup at smc.vnet.net*Subject*: [mg56738] Re: [mg56683] Variant of inner Product ...*From*: Bob Hanlon <hanlonr at cox.net>*Date*: Thu, 5 May 2005 06:01:21 -0400 (EDT)*Reply-to*: hanlonr at cox.net*Sender*: owner-wri-mathgroup at wolfram.com

A sum of equal length Lists is the List of sums. Hence your requested output is {f[1,a],f[1,b]}+{f[2,c],f[2,d]}+{f[3,r],f[3,s]} {f(1,a)+f(2,c)+f(3,r),f(1,b)+f(2,d)+f(3,s)} which is to say A={1,2,3};B={{a,b},{c,d},{r,s}}; {f[1,a],f[1,b]}+{f[2,c],f[2,d]}+{f[3,r],f[3,s]} == Inner[f,A,B] True Bob Hanlon > > From: Detlef Müller at smc.vnet.net To: mathgroup at smc.vnet.net > Date: 2005/05/04 Wed AM 12:32:49 EDT > Subject: [mg56738] [mg56683] Variant of inner Product ... > > Hello, > > I have the following to do: > > Given > > In[1]:= A={1,2,3}; B={{a,b},{c,d},{r,s}}; > > And a Function f, I like to have > > Out[2] = {f[1,a],f[1,b]}+{f[2,c],f[2,d]}+{f[3,r],f[3,s]} > > The trial > > In[8]:=A={1,2,3}; B={{a,b},{c,d,e},{r,s}}; > In[9]:= Inner[f,A,B] > Out[9]= f[1,{a,b}]+f[2,{c,d,e}]+f[3,{r,s}] > > looks promising, > but if the Lists in B have the same length, "Inner" > makes something different: > > In[15]:= > A={1,2,3}; B={{a,b},{c,d},{r,s}}; Inner[f,A,B] > > Out[16]= {f[1,a]+f[2,c]+f[3,r],f[1,b]+f[2,d]+f[3,s]} > > So for now I have an ugly Table-Construction doing the job, > but I can't imagine there is no elegant and clear solution > for this ... any suggestions? > > Greetings, > Detlef > >