Re: averaging sublists of different lengths

*To*: mathgroup at smc.vnet.net*Subject*: [mg75509] Re: [mg75466] averaging sublists of different lengths*From*: bsyehuda at gmail.com*Date*: Thu, 3 May 2007 03:50:54 -0400 (EDT)*References*: <200705020747.DAA04729@smc.vnet.net>

call your list l then With[{ml = Max[Length /@ l]}, Table[Mean[Flatten[Map[If[Length[#] >= i, #[[i]], {}] &, l]]], {i, ml}]] so for your data the result is {686/11, 692/11, 710/11, 716/11, 714/11, 706/11, 328/5, 257/4, 456/7, 502/7, 212/3, 74, 250/3, 80, 74, 64, 88, 56} regards yehuda On 5/2/07, dantimatter <dantimatter at gmail.com> wrote: > > > 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 > > >

**References**:**averaging sublists of different lengths***From:*dantimatter <dantimatter@gmail.com>