Message-ID: <F270C07E-C7C3-4A29-BFDE-08C5691D73DF@comcast.net>
Date: 2012-09-10T18:03:09Z
From: David Winsemius
Subject: pairwise comparisions
In-Reply-To: <1347285622093-4642656.post@n4.nabble.com>
On Sep 10, 2012, at 7:00 AM, priya wrote:
> Hi ,
> I am new to R .
How new? Is this still in a file? ... or has it been imported to an R object. If it really still is in a file, then Bert's suggestion of first reading "Intro to R" rather than posting to R help is on point. If it is an R object, you _should_ have used dput(head(obj)) to provide an appropriate test case for solutions.
> I am facing difficulty how to make pairwise comparisions.
> For example. I have a file which looks like below
> a b c d
> x 3 6 7 6
> y 7 8 6 5
> z 5 4 7 8
> Here I need to look for the each pairwise comparisions (ab,ac,ad,bc,bd,cd
> for each row)
Let's assume it's in a matrix of data.frame named X. To get pairwise combinations try:
CX <- combn( colnames(X), 2)
That's going to be a 2 row character matrix. Perhaps this will work but since you provide not example it will remain untested.
apply(CX, 2, function(comb), pmin(X[, comb[1]], X[, comb[2]] ) )
> For instance ,looking at first row, for x i need to look for ab values and
> take the min(3,6) >5 ,if its satistfies the count should be noted, (now
> count is 0), bc values ,min(6,7) >5 ,count for x =1 etc. Likewise all the
> comparisons are made and count is noted for x,y,z.
> Is there any function to make pairwise comparisions in R or any easy way to
> do this?
> Any help is greatly appreciated.
--
David Winsemius, MD
Alameda, CA, USA