vectorizing

[Ita Cirovic <zag_cirovic@yahoo.com>]

Hi,

I have the following code and I am trying to use apply functions to get rid of the for loops, so far I have the following. Any suggestions about the remaining for loop as this takes a bit long given that x has around 15000 observations. Thanks.

# original
for (i in 1:length(x)){      # x is a matrix
    for (j in 1:length(x[,1]){
       wx[j] <- max(min(x[j,],up[i]),lb[i])
       wr[j,i] <- wx[j]
    }
}


# replaced one for loop with apply

wr <- apply(x,2,function(x){
                           for (i in 1:length(x)) 
                               max(min(x,up[i]),lb[i])
                       })

where up and lb are vectors of length the same as x matrix.

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