loop and sapply problem, help need

Dear R experts

Sorry for this question

M1 <- 1:10
lcd1 <- c(11, 22, 33, 44, 11, 22, 33, 33, 22, 11)
lcd2 <- c(22, 11, 44, 11, 33, 11, 22, 22, 11, 22)
lcd3 <- c(12, 12, 34, 14, 13, 12, 23, 23, 12, 12)

#generating variables through sampling
pvec <- c("PR1", "PR2", "PR3", "PR4", "PR5", "PR6", "PR7", "PR8", "PR9",
"PR10")
fun11 <- function(x){
  smpool <- c(1,2,3,3)
 x <-  sample(smpool, 10, replace= TRUE)
 }
newd <- sapply (pvec, fun11)


# function to recode this new generated data
fun3 <- function(x) {
      (if ( x ==1){
     x = lcd1
   }else  if (x ==2){
       x = lcd2
   }  else if ( x ==3 ){
        x = lcd3
       } else x = NA )
               return(x)
             }
Applying the function:
pn <- sapply (newd, fun3)

I am getting 10 x 100 matrix, in contrast to 10 x 10 what I am expecting !

My objective here is to replace data points in all variables in newd
with corresponding value with values vector lcd1 or lcd2 or lcd3 depending
upon whether they are 1 or 2 or 3.
For example;

lcd1 <-   c(11, 22, 33, 44, 11, 22, 33, 33, 22, 11)
lcd2 <-   c(22, 11, 44, 11, 33, 11, 22, 22, 11, 22)
lcd3 <-   c(12, 12, 34, 14, 13, 12, 23, 23, 12, 12)

PR1 <-    c(1,   2,   3,    2,   1,  1,   1,   2, 3,   1)

with the new
PR1n <- c(11,  11,   34,  11,  11, 22, 33, 22, 12, 11)
# as the first element of this vector is determined by PR1[1] indicator
determines whether to pick lcd1[1] or lcd2[1] or lcd3[1] element
similarly for PR1[2] indicator whether to pick lcd1[2] or lcd2[2] or lcd3[2]
element

The same process need to be continued other PR2 to PR10 variables. That's
why I attempted to use sapply.

Thank you for your help


-- 

Ram H

	[[alternative HTML version deleted]]

x <- read.table(textConnection("

closeAllConnections()
x  # before

# extract data to matrix for easier processing
lcd <- as.matrix(x[grepl("^lcd", names(x))])
# now process each 'PR' column
for (i in grep("^PR", names(x), value = TRUE)){

x # after

Hi Phil and R users

Let me clear my problem. The generating sample is not prime issue here. I am
simulating a situation, for which I need to sample. But once I have sampling
done, I need to do a conditional decoding. Let me clear it with more clear
data example:

x <- read.table(textConnection("
mark lcd1 lcd2 lcd3 PR1 PR2 PR3 PR4
1 11 22 ?12 1 2 3 1
2 33 44 ?34 1 2 3 1
3 22 44 ?24 3 1 2 1
4 11 33 ?13 2 2 1 3
5 22 11 12 3 2 2 1 "), header = TRUE)

I want to do a conditional formatting of PR1:PR4 (in real sense I have

20000 such variables) based on corrsponding value in variable column lcd1

or lcd2 or lcd3.

mark lcd1 lcd2 lcd3 PR1 PR2 PR3 PR4
1 ? ? ? 11 ? ? 22 ? 12 ? ? ?1 ? ? 2 ? ? 3 ? ? ?1
2 ? ? ? 33 ? ? ?44 ?34 ? ? ?1 ? ? 2 ? ? 3 ? ? ?1
3 ? ? ? 22 ? ? ?44 ?24 ? ? ?3 ? ?1 ? ? ?2 ? ? ?1
4 ? ? ?11 ? ? ? 33 ?13 ? ? ?2 ? ?2 ? ? ?1 ? ? ?3
5 ? ? ? 22 ? ? ?11 ?12 ? ? ?3 ? ?2 ? ? ?2 ? ? ?1

If PR1 =1, then PR1= lcd1
? PR1=2, then PR1 = lcd2
? PR1=3, then PR1 = lcd3
? ? similarly for PR2...................to end of files PR4

#Expected Output
mark lcd1 lcd2 lcd3 PR1 PR2 PR3 PR4
1 11 22 12 11 22 12 11
2 33 44 34 33 44 34 33
3 22 44 24 24 22 44 22
4 11 33 13 33 33 11 13
5 22 11 12 12 11 11 22

Thank you;

Ram H




On Sat, Apr 9, 2011 at 4:13 PM, Phil Spector <spector at stat.berkeley.edu>wrote:

Ram -
? I think you'll have to explain what you're trying to do.
? First, you're creating a 10x10 matrix newd, which could
be done a bit more efficiently by using

? ?newd = matrix(sample(c(1,2,3,3,),10*length(pvec),replace=TRUE),ncol=10)

? Notice that calling sapply on a matrix applies the function to each
element of the matrix.

? But your fun3 function really doesn't make sense, since you are testing
each scalar element for equality to a scalar, and then setting
it equal to a vector. ?It seems to me that what you're trying to do is


? ? ? smpool = c(1,2,3,3)
? ? ? allvals = rbind(lcd1,lcd2,lcd3)
? ? ? pn = replicate(10,allvals[sample(smpool,1),])

but I can't be sure.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?- Phil Spector
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Statistical Computing Facility
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? Department of Statistics
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? UC Berkeley
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? spector at stat.berkeley.edu



On Sat, 9 Apr 2011, Ram H. Sharma wrote:

?Dear R experts

Sorry for this question

M1 <- 1:10
lcd1 <- c(11, 22, 33, 44, 11, 22, 33, 33, 22, 11)
lcd2 <- c(22, 11, 44, 11, 33, 11, 22, 22, 11, 22)
lcd3 <- c(12, 12, 34, 14, 13, 12, 23, 23, 12, 12)

#generating variables through sampling
pvec <- c("PR1", "PR2", "PR3", "PR4", "PR5", "PR6", "PR7", "PR8", "PR9",
"PR10")
fun11 <- function(x){
?smpool <- c(1,2,3,3)
?x <- ?sample(smpool, 10, replace= TRUE)
?}
newd <- sapply (pvec, fun11)


# function to recode this new generated data
fun3 <- function(x) {
? ? ?(if ( x ==1){
? ? x = lcd1
? }else ?if (x ==2){
? ? ? x = lcd2
? } ?else if ( x ==3 ){
? ? ? ?x = lcd3
? ? ? } else x = NA )
? ? ? ? ? ? ? return(x)
? ? ? ? ? ? }
Applying the function:
pn <- sapply (newd, fun3)

I am getting 10 x 100 matrix, in contrast to 10 x 10 what I am expecting !

My objective here is to replace data points in all variables in newd
with corresponding value with values vector lcd1 or lcd2 or lcd3 depending
upon whether they are 1 or 2 or 3.
For example;

lcd1 <- ? c(11, 22, 33, 44, 11, 22, 33, 33, 22, 11)
lcd2 <- ? c(22, 11, 44, 11, 33, 11, 22, 22, 11, 22)
lcd3 <- ? c(12, 12, 34, 14, 13, 12, 23, 23, 12, 12)

PR1 <- ? ?c(1, ? 2, ? 3, ? ?2, ? 1, ?1, ? 1, ? 2, 3, ? 1)

with the new
PR1n <- c(11, ?11, ? 34, ?11, ?11, 22, 33, 22, 12, 11)
# as the first element of this vector is determined by PR1[1] indicator
determines whether to pick lcd1[1] or lcd2[1] or lcd3[1] element
similarly for PR1[2] indicator whether to pick lcd1[2] or lcd2[2] or
lcd3[2]
element

The same process need to be continued other PR2 to PR10 variables. That's
why I attempted to use sapply.

Thank you for your help


--

Ram H

? ? ? ?[[alternative HTML version deleted]]

--

Ram H

? ? ? ?[[alternative HTML version deleted]]