[R] rowsum- is there a countsum

[Anders Bjørgesæter]

Hello

Is there an analogous function to ”rowsum” that count the numbers 
according to a given vector (preferably larger than a given value) 
instead of summing them?

E.g. rowsum(x, group)

X is the dataframe, 	A	B	C
			5	0	0
			1	3	3
			0	1	12
and group is the vector; 1,1,2

rowsum gives: 		A	B	C
		1	6	3	3
		2	0	1	12


I want: 		A	B	C
		1	2	1	1
		2	0	1	1

for e.g. count all > 0.

Best Regards
Anders