R: Convert Matrix to YES, NO dataframe -


i have matrix this

df <- matrix(c(rep(1,3),rep(2,3)),nrow=3,ncol=2)  df:        [,1] [,2] [1,]    1    2 [2,]    1    2 [3,]    1    2

i want convert every cell value yes, if greater 0, else no

i understand can using 

apply(df, 2, function(x) ifelse(x > 0, "yes","no"))

however matrix huge (million * 5000), , hence using apply takes insanely large time

i have tried

df <- ifelse(df > 0, "yes","no")

however takes lot of time

can achieve better performance this?

here's 1 way create matrix:

df[] <- c("no", "yes")[(df > 0) + 1]

the result:

     [,1]  [,2]  [1,] "yes" "yes" [2,] "yes" "yes" [3,] "yes" "yes"

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