Averaging 'blocks' of data
On Sun, Sep 7, 2008 at 12:32 PM, Steve Murray <smurray444 at hotmail.com> wrote:
Dear all, I have a large dataset which I hope to reduce in size, to make it more useable. I hope to do this by taking an average of each 60 x 60 blockof values and forming a new data frame out of the averaged values.
what does the data look like? vector / matrix / list ?
How would I go about taking averages of 60 x 60 'blocks' in R, and cycling through the whole dataset, recording each calculated value in a new table/data frame?
some form of apply(), tapply(), mapply(), or lapply() would probably do what you want
Many thanks for any advice offered. Steve
Here is a start: # step 1. too much data: 10x10 matrix m <- matrix(runif(100), ncol=10) # step 2. reduce down to a 10x1 vector, averaging-by-row: apply(m, 1, mean) # step 3 profit. Dylan