r - How to filter out matrix rows with entries less than specific value

Question

I'm dealing with very big matrix. I want just keep the rows of the matrix which 90% of it's entries are bigger than 10. Since I'm not familiar much with R, would someone help me to implement this ?

Answer 1

I would just use rowSums and common comparison operators.

Here's a minimal example:

set.seed(1); m <- matrix(sample(50, 100, TRUE), ncol = 10)
rowSums(m > 10) == ncol(m)
#  [1]  TRUE FALSE  TRUE FALSE FALSE FALSE FALSE FALSE FALSE FALSE
m[rowSums(m > 10) == ncol(m), ]
#      [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
# [1,]   14   11   47   25   42   24   46   17   22    12
# [2,]   29   35   33   25   40   22   23   18   20    33

To accommodate a fractional approach, try something like:

m[rowSums(m > 10) >= (.9 * ncol(m)), ]