Re: averaging sublists of different lengths

*To*: mathgroup at smc.vnet.net*Subject*: [mg75497] Re: averaging sublists of different lengths*From*: "Rolf.Mertig at gmail.com" <Rolf.Mertig at gmail.com>*Date*: Thu, 3 May 2007 03:44:33 -0400 (EDT)*References*: <f19fql$4q7$1@smc.vnet.net>

Hi, one possibility is: Mathematica 6.0 for Linux x86 (64-bit) Copyright 1988-2007 Wolfram Research, Inc. In[1]:= FilePrint@"m.m" MyMean[mat:{{__?NumberQ}..}]:=Module[{max,tmat}, max=Max[Length/@mat]; tmat=Transpose[PadRight[#,max,Hold[Sequence[]]]&/@mat]; Mean/@ReleaseHold[tmat]]; InputForm @ MyMean[ {{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}} ] In[2]:= <<m.m Out[2]//InputForm= {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, Rolf Mertig GluonVision GmbH http://www.gluonvision.com On 2 Mai, 09:49, dantimatter <dantimat... 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