Hi, Is there a way to apply the diff operator over a large data frame, by groups in a single function?
I have a toy data frame that looks like this:
MEASUREMENT BLOCK TRATMENT VALUE1
VALUE2
1 1
T-01 15 1
1 1
T-02 32 2
1 2
T-01 21 5
1 2
T-02 32 6
2 1
T-01 19 5
2 1
T-02 37 2
2 2
T-01 29 3
2 2
T-02 36 6
3 1
T-01 21 21
3 1
T-02 45 22
3 2
T-01 38 32
3 2
T-02 40 31
.
.
.
What I would like to calculate is a dataframe that takes the difference between
measurements over the same BLOCK-TRATMENT for VALUE1 and VALUE2
Any one know?
Cheers,
Cristián Montes
[[alternative HTML version deleted]]
______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
