Re: list manipulation, mean value

*To*: mathgroup at smc.vnet.net*Subject*: [mg22991] Re: list manipulation, mean value*From*: "Deborah Leddon " <Dleddon at students.cas.unt.edu>*Date*: Sun, 9 Apr 2000 01:45:54 -0400 (EDT)*Organization*: University of North Texas*Sender*: owner-wri-mathgroup at wolfram.com

Hello, I have a rather involved question on how to partition a data list into sliding windowed components and then calculate a mean value followed by a running standard deviation. For example, for the following data list: lis ={ 1,0,2,1,3,4} with a length of n=6, I want to take groups of data points of lengths running from 1 to n= 6 (length of the data list), perform a mean value and then take a running standard deviation (STD) as shown below: For a group of length = 1, take from lis: w(1) = {1,0,2,1,3,4} perform mean value of each number (sublist;group length =1) to get {1,0,2,1,3,4}, perform running standard deviations (STD) to get: {STD[1], STD[{1,0}], STD[{1,0,2}], STD[{1,0,2,1}], STD[{1,0,2,1,3}], STD[{1,0,2,1,3,4}]} then put into a list called lets say "final". For the next group of length = 2, take from lis: w(2) = { {1,0}, {0,2}, {2,1},{1,3}, {3,4} }, *(note this is not just a partition of the list, but a sliding one)* get the mean value of each sublist; {1, 1, 1.5, 2, 3.5}; perform running standard dev.; STD[{1}], STD[{1,1}], STD[{1,1,1.5}], STD[{1,1,1.5,2}], STD[{1,1,1.5,2,3.5}] then append these STD values to the list 'final'. then so on for w(3),.....,w(n=6). Eventually the goal is to get a 'final' list of running standard deviations in order to plot. If anyone can help, I'd really appreciate it. Thanks for your time. Debbie