r data.table percentage of rowsum

Asked Nov 29 '16 at 11:23

Active Nov 29 '16 at 11:26

Viewed 137 times

I'm probably facing an easy probleme here, but I just can't get it to work. I have a data.table as such:

data.table(replicate(3,sample(1:100,5,rep=TRUE)))

   V1 V2 V3
1: 80 56 33
2: 28 97 39
3: 50 30 38
4: 13 35 52
5: 55  1 68

And I'd like to calculate the percentage of each column attributing to the row sum as such:

   V1 V2 V3 sum
1: 47 33 20 100
2: 17 59 24 100
3: 42 25 32 100
4: 13 35 52 100
5: 44  1 55 100

I tried to calculate the rowsum first and the individually divide each column by rowsum and round up. Is there a better way to do so?

edited Nov 29 '16 at 11:26

Ronak Shah

asked Nov 29 '16 at 11:23

jaydee

Do you need `dt/rowSums(dt) * 100` ? – Ronak Shah Nov 29 '16 at 11:25
have a look at prop.table See this question [link]http://stackoverflow.com/questions/9623763/in-r-how-can-i-compute-percentage-statistics-on-a-column-in-a-dataframe-tabl – Etienne Moerman Nov 29 '16 at 11:27
And a question matching even closer http://stackoverflow.com/questions/16032826/calculate-row-wise-proportions?noredirect=1&lq=1 – Etienne Moerman Nov 29 '16 at 11:42
thanks for the hint! – jaydee Nov 29 '16 at 15:06

0 Answers0