Displaying 2 results from an estimated 2 matches for "avgmat".
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amat
2007 Jun 07
1
Averaging across rows & columns
...need to average to get
one reading per fruit; each row is a point in the light spectrum and I need
to calculate an average reading every 5nm -14 rows- for each fruit).
Someone proposed to another user who wanted an avg across columns to do
a <- matrix(rnorm(360),nr=10)
b <- rep(1:12,each=3)
avgmat <- aggregate(a,by=list(b))
I tried doing this to get started with the columns first but it asks for an
argument FUN that has no default. The help for aggregate isn't helping me
much (a new R user) to discover what value to give to FUN -'average' doesn't
seem to exist, and '...
2006 Mar 06
4
Averaging over columns
Hi
I've been reading the help for by and aggregate but can't get my head
round how to do this.
I have a data frame - the first three columns are replicate
measurements, then the next 3 are replicates etc up to 36 (so 12
variables with 3 replicate measurements each). I want to compute the
mean for each of the 12 variables, so that, for each row, I have 12
means.
A grouping variable