Re: vectorizing

[Ita Cirovic <zag_cirovic@yahoo.com>]

if using 'pmin' and 'pmax' shouldn't the args. x and y for the two functions be of the same length where I am trying to use max and mix for the following

x = 11000 x 5
up = 5 x 1
lb = 5 x 1

so I am comparing 11000 rows with only one value of up and lb.

Ita

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I think you are looking for 'pmin' and 'pmax'.

Patrick Burns
patrick@burns-stat.com
+44 (0)20 8525 0696
http://www.burns-stat.com
(home of S Poetry and "A Guide for the Unwilling S User")

Ita Cirovic wrote:

> 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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