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