Hi All

I am having problem running the 'attributes' command to set a attribute on
each column of a large dataset. Dataset has 80 columns and 312407 rows. Its
taking more than 60 seconds to set simple attributes like split=TRUE,
usermissing=FALSE.

Here is the source code, assuming Dataset1 is the one that is large :-

myfunction <- function()
{
cat("Before for loop:")
print(Sys.time())
for( colIndex in 1 : 80)
{
cat("Before Attr", colIndex)
print(Sys.time())

attributes(Dataset1[1]) <- c(attributes(Dataset1[, colIndex]), list(coldesc
= c(), usermissing = c(FALSE), missingvalues  = NULL, split = c(FALSE),
levelLabels = c("")))

cat("After Attr:")
print(Sys.time())
}
cat("After for loop:")
print(Sys.time())
}

Its my feeling that R is passing all 312407 rows to set 'attributes' on a
cloumn.

Is there a more efficent way to do this?


Thanks,
SG

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