How to find mean(row)/var(row) for my matrix in R-CodePudding

I have a 100x100 matrix of rgamma realisations. I need to find the x = (mean(row)/var(row)) in order to find the SD(x). How do I loop through my matrix for this? Please kindly help, I am unsure of R syntax

data = matrix(rgamma(100,4.623371,2.757291), nrow=100)

rowMeans(data)

CodePudding user response：

Given a matrix data the following divides the row mean by the variance of that same row, for all rows.

apply(data, 1, \(x) mean(x) / var(x))

CodePudding user response：

First, to get a 100 x 100 matrix, you need an input of 1e4 (100*100). Second, you could look at the sparseMatrixStats package which has the functions rowMeans2 and rowVars as well as rowSds. I'm not sure if you want SDs per row or total.