are you looking for s.th. like this?
# some data
m<-c(3,1,2,4,4,4,4,0,5,4,4,5,6,1,1,1)
m<-as.data.frame(matrix(m,4,4))
print(m)
# sort m -- if necessary
m<-m[order(m[,3]),]
m<-m[order(m[,2]),]
# compute sums
cum<-cumsum(m[,4])
# find rows
ind<-c(T,0!=diff(m[,2] )| 0!=diff(m[,3]))
ind<-c(ind[-1],T)
# combine result
mneu<-cbind(m[ind,-4],V4=diff(c(0,cum[ind])))
print(mneu)
initial matrix:
V1 V2 V3 V4
1 3 4 5 6
2 1 4 4 1
3 2 4 4 1
4 4 0 5 1
result:
V1 V2 V3 V4
4 4 0 5 1
3 2 4 4 2
1 3 4 5 6
result without sorting
V1 V2 V3 V4
1 3 4 5 6
3 2 4 4 2
4 4 0 5 1
Peter Wolf
Fred J. wrote:
>Hello
>I have a data frame with many col.s and rows
>V4 V5 V6 V7
>3 4 5 6
>1 4 4 1
>2 4 4 1
>4 0 5 1
>
>since the data has the middle 2 rows with V5 and V6
>are equal, I need to produce
>V4 V5 V6 V7
>3 4 5 6
> this line removed and the value V7 = 1 is
>
> added to the next row V7 valuve making it
>2
>2 4 4 2
>4 0 5 1
>
>thanks a lot
>
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