Hi I am working on the following dataframe(nows
= 62208):
> head(workfile)
V1 V5 V7 V8 V9
4309 2014-03-01 13:30:00 1582.899 D.1Elec-0001 D.1 Elec-0001
6801 2014-03-01 13:45:00 1582.900 D.1Elec-0001 D.1 Elec-0001
6805 2014-03-01 14:00:00 1582.919 D.1Elec-0001 D.1 Elec-0001
5710 2014-03-01 14:15:00 1582.939 D.1Elec-0001 D.1 Elec-0001
5714 2014-03-01 14:30:00 1582.944 D.1Elec-0001 D.1 Elec-0001
6814 2014-03-01 14:45:00 1582.945 D.1Elec-0001 D.1 Elec-0001
I would like to compute the differences between each element in column (V5
) and its previous one inserted in the same column (V5
) but in a previous row. In column V7
I have 72 different levels (in my case 72 different rooms).
If I use this code:
pippo<-ddply(workfile, .(V7), transform, diff = c(tail(V5,-1)-head(V5,-1)), NA)
it occurs the following error message:
Error in data.frame(list(V1 = c(1393680600, 1393681500, 1393682400, 1393683300,:
arguments imply differing number of rows: 864, 863, 1
If I use this code:
pippo<-ddply(workfile, .(V7), transform, diff = c(tail(workfile$V5,-1)-head(workfile$V5,-1)), NA)
it occours this other error message:
Error in data.frame(list(V1 = c(1393680600, 1393681500, 1393682400, 1393683300,: arguments imply differing number of rows: 864, 62207, 1
I cannot dput
my dataframe because it is very big.
Any suggestion, please?