From: Gabor Grothendieck <ggrothendieck_at_myway.com>

Date: Mon 21 Feb 2005 - 03:16:15 EST

R-devel@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-devel Received on Mon Feb 21 02:26:23 2005

Date: Mon 21 Feb 2005 - 03:16:15 EST

Melanie Vida <mvida <at> mac.com> writes:

*:
*

: In R, I'm imported a data frame of 2,321,123 by 4 called "dataF".

*: I converted the data frame "dataF" to a matrix
**:
**: dataM <- as.matrix(dataF)
**:
**: Does R have an efficient routine to treat the special elements that
**: contain "inf" in them. For example, can you separate the rows that have
**: "inf" elements from the matrix into a separate matrix without iterating
**: over the entire matrix?
*

This will eliminate all rows that contain Inf or -Inf.

m[apply(is.finite(m), 1, all),]

*:
*

: Also, does R have an efficient way to sort columns in a matrix?

This can be interpreted a number of different ways:

See

?order

?sort

m[order(m[,1]),] # sorts so that column 1 is sorted and rows stay together apply(m, 2, sort) # sort each column separately

R-devel@stat.math.ethz.ch mailing list

https://stat.ethz.ch/mailman/listinfo/r-devel Received on Mon Feb 21 02:26:23 2005

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