Re: averaging sublists of different lengths
- To: mathgroup at smc.vnet.net
- Subject: [mg75512] Re: averaging sublists of different lengths
- From: dimitris <dimmechan at yahoo.com>
- Date: Thu, 3 May 2007 03:52:30 -0400 (EDT)
- References: <f19fql$4q7$1@smc.vnet.net>
In[151]:= lst = {{70, 66, 64, 68, 64, 56, 68, 78, 62, 68, 84}, {70, 64, 64, 56, 66, 56, 62, 64, 66, 88, 54, 72}, {58, 54, 54, 60, 72, 70, 62, 68, 74, 76, 70}, {66, 56, 60, 64, 56, 62, 68, 58, 58, 58, 68, 76, 62, 76, 66, 64, 88, 56}, {56, 64, 72, 72, 70, 62, 76, 76, 76, 76, 86, 80, 100}, {60, 60, 70, 68, 60, 60, 50, 56, 60, 70, 62, 68, 88, 84, 82}, {54, 66, 72, 62, 70, 66, 70, 56}, {60, 60, 60, 62, 74, 80, 70}, {54, 62, 64, 72, 76, 74}, {66, 74, 70, 80, 54, 54, 64}, {72, 66, 60, 52, 52, 66, 66, 58, 60, 66}, {3}, {0, 0}}; In[142]:= Mean /@ lst Out[142]= {68, 391/6, 718/11, 581/9, 966/13, 998/15, 129/2, 466/7, 67, 66, 309/5, 3, 0} In[144]:= (Tr[#1]/Length[#1] & ) /@ lst Out[144]= {68, 391/6, 718/11, 581/9, 966/13, 998/15, 129/2, 466/7, 67, 66, 309/5, 3, 0} In[145]:= (Total[#1]/Length[#1] & ) /@ lst Out[145]= {68, 391/6, 718/11, 581/9, 966/13, 998/15, 129/2, 466/7, 67, 66, 309/5, 3, 0} In[146]:= (Plus @@ #1/Length[#1] & ) /@ lst Out[146]= {68, 391/6, 718/11, 581/9, 966/13, 998/15, 129/2, 466/7, 67, 66, 309/5, 3, 0} In[148]:= ((#1 /. {x_, y___} -> x + y)/Length[#1] & ) /@ lst Out[148]= {68, 391/6, 718/11, 581/9, 966/13, 998/15, 129/2, 466/7, 67, 66, 309/5, 3, 0} ??? Dimitris =CF/=C7 dantimatter =DD=E3=F1=E1=F8=E5: > Hello all, > > I have a list of lists like this: > > {{70, 66, 64, 68, 64, 56, 68, 78, 62, 68, 84}, {70, 64, 64, 56, 66, > 56, 62, > 64, 66, 88, 54, 72}, {58, 54, 54, 60, 72, 70, 62, 68, 74, 76, 70}, > {66, > 56, 60, 64, 56, 62, 68, 58, 58, 58, 68, 76, 62, 76, 66, 64, 88, > 56}, {56, > 64, 72, 72, 70, 62, 76, 76, 76, 76, 86, 80, 100}, {60, 60, 70, 68, > 60, 60, > 50, 56, 60, 70, 62, 68, 88, 84, 82}, {54, 66, 72, 62, 70, 66, > 70, > 56}, {60, 60, 60, 62, 74, 80, 70}, {54, 62, 64, 72, 76, 74}, {66, > 74, 70, > 80, 54, 54, 64}, {72, 66, 60, 52, 52, 66, 66, 58, 60, 66}} > > What I'd really like is the average all the 1st values, 2nd values, > etc, but I'm having trouble figuring out how to deal with the fact > that the lists are not all the same length. Is there a way to drop > the sublists as they run out of points to add to the average, i.e. if > I want the average of all the nth values, but Length[shortSublist] < > n, can I somehow drop shortSublist and then calculate the average from > the other sublists? > > Also, the Mean[] function requires more than one data point, but I'd > still like to extract out the values for which there is only one data > point. Is there a way to do this? > > Thanks! > dan