[R] for() loop
Schmidt Martin
m.schmidt at students.unibe.ch
Sun Mar 14 21:49:45 CET 2010
Hello
I'm working with R since a few month and have still many trivial
questions - I guess! Here is what I want:
I have this matrix:
> dim(datjan)
[1] 899 4
The first 10 rows looks as follows:
> datjan[1:10,]
V1 V2 V3 V4
1 1961 1 1 24
2 1961 1 2 24
3 1961 1 3 24
4 1961 1 4 24
5 1961 1 5 24
6 1961 1 6 27
7 1961 1 7 27
8 1961 1 8 27
9 1961 1 9 27
10 1961 1 10 27
I tried now to create a for() loop, which gives me the sum of the 30
different classes (1:30!) in [,4].
for(i in 1:30){
sum(datjan[,4]==i)
}
R is then actually calculating the sum of "i" which certainly doesn't
exist and results in a "0" value
t1<-sum(datjan[,4]==1)
t2<-sum(datjan[,4]==2)
.................................until '30'
This way its working, but I won't find a end by doing all this by
hand, because there are many other matrix waiting.
So, how can I make work that loop??
thanks for helping me
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