remove column

*Hi all,*



I'm trying to filter a file through the columns. This file below is a
example of my data frame. My true data frame has seven hundred thousand
columns and 500 hundred lines. I need to identify and to remove all columns
that all elements equal a number 1. In this my case, columns were deleted
are number 1,5 and 10.





file <-read.table(text="

1  0  2  2  1  1  5  1  1  1

1  0  2  2  1  1  5  1  1  1

1  0  2  2  1  2  5  2  2  1

1  0  2  2  1 1  5  1  1  1

1  0 2  2   1  0  5  0  2  1

1  0  2 2   1  1  5  1  0  1

",sep="",header=FALSE)



the result after the filter will be



0  2  2  1  5  1  1

0  2  2  1  5  1  1

0  2  2  2  5  2  2

0  2  2  1  5  1  1

0  2  2  0  5  0  2

0  2  2  1  5  1  0



I used this commands idlength<-sapply(file,function(x) length(unique(x))
),

but came an error message:



caught segfault ***

address 0x4, cause 'memory not mapped'

*My question: is it possible to remove the all columns from above file
to *achieve* the desired result?*