RE: [R] aggregate function

From: Gabor Grothendieck <ggrothendieck_at_myway.com>
Date: Tue 27 Jul 2004 - 05:12:30 EST

[Sorry if this gets posted twice. I have been having some problems with gmane posting.]

We can use rowsum like this:

> rowsum(frame$Total * (frame[,3:5]>0), frame$Year)

	Tus Whi Norw
	1994 1 0.00 1
	1995 1 1.00 1
	1997 2 4.00 5
	1998 0 0.00 1
	1999 1 2.04 2

Note that only years that are actually present will be in the resulting matrix. 1996 is not in the sample data in your post so there is no row for 1996. If that's not a problem or if your real data covers all the years anyways we are done.

If missing years is a problem then merge in some zero rows with the years first. The first two lines below do this and the third line is the same as the line above:

> frame <- merge(frame, 1994:1999, by = 1, all = TRUE)
> frame[is.na(frame)] <- 0

> rowsum(frame$Total * (frame[,3:5]>0), frame$Year)

	Tus Whi Norw
	1994 1 0.00 1
	1995 1 1.00 1
	1996 0 0.00 0 <-- now we have a row for 1996
	1997 2 4.00 5
	1998 0 0.00 1
	1999 1 2.04 2


Luis Rideau Cruz <Luisr@frs.fo> :

I have the folowing frame(there are more columns than shown), 1 2 3 4 5
Year Total Tus Whi Norw

1994 1.00 1830 0 355
1995 1.00 0 0 0
1995 1.00 0 0 0
1995 1.00 4910 4280 695
1997 1.00 0 0 110
1997 0.58 0 0 0
1997 1.00 0 0 0
1994 1.00 0 0 0
1997 1.00 0 40 70
1998 1.00 0 0 1252
1999 1.04 0 74 0
1999 1.00 0 0 0
1999 1.02 0 0 0
1999 1.00 0 0 0
1999 1.00 0 0 171
1999 1.00 1794 0 229
1999 1.00 0 3525 0
1997 1.00 1335 1185 147
1997 1.00 4925 1057 4801
1997 1.00 0 6275 1773

I try to get sum("Total") by "Year" in which Tus>0, sum("Total") by "Year" in which Whi>0,,,and so on.

I have done something like this;

a<-as.list(numeric(3))
for (i in 3:5)
{
a[[i]]<-aggregate(frame[,"Total"],list(Year=frame$"Year", Tus=frame$"i">0),sum)
}

But I get

"Error in FUN(X[[as.integer(1)]], ...) : arguments must have same length"

Also by doing one by one

aggregate(frame[,"Total"],list(Year=frame$"Year", Tus=frame$"Tus">0),sum)

The result is something like;

Year Tus x

1994 FALSE 49.69
1995 FALSE 49.35
1996 FALSE 56.95
1997 FALSE 57.00
1998 FALSE 57.00
1999 FALSE 58.09
2000 FALSE 56.97
2001 FALSE 57.95
2002 FALSE 57.10
2003 FALSE 56.16
2000 TRUE 1.00

2002 TRUE 1.00
2003 TRUE 2.01

R-help@stat.math.ethz.ch mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Tue Jul 27 05:19:47 2004

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