Help massaging big arrays
On Fri, 2 Aug 2002, Philip Rhoades wrote:
Hi all, I hope someone can give me some quick pointers - it would take me ages to work this out from scratch - I want to: - From an array - 32 cols x 1000 rows of small floats
Call it X
- Produce a second array from the first where the all numbers have an abs fn applied to them (to get rid of the neg numbers)
X <- abs(X)
- Produce a third array from the second where all numbers less than 0.0005 are converted to 0.0005
X[X<0.005] <- 0.005
- Produce a fourth array (5x1000) from the third where the first number in the row is the mean of the first two numbers of array #3, the second number is the mean of the first 4 numbers, 3rd mean of 8, 4th mean of 16, 5th mean of 32
Y<-matrix(ncol=5,nrow=1000)
for(i in 1:5)
Y[,i] <- rowMeans(X[ ,1:(2^i)])
- Produce a fifth (5x1000) array by dividing array #4 into another 5x1000 array
Y <- Z/Y
- Produce 5 means of the 5 columns of array #5
colMeans(Y) -thomas -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._