CODEWITHSUNDEEP
rsumaggregate
Newby
Newby

Reputation: 11

Aggregate/sum with dimension in row and colum

I know the standard aggregate function, example code

aggregate(hp~cyl/vs, data=mtcars, FUN="sum", na.rm=TRUE)

that returns:

  cyl vs   hp
1   4  0   91
2   6  0  395
3   8  0 2929
4   4  1  818
5   6  1  461

However i would like to put the "vs" in the columns, like this:

      vs   0    1
  cyl     hp   hp
1   4     91   818
2   6    395   461
3   8   2929

How can this be done in R?

Upvotes: 1

Views: 94

Answers (3)

davechilders
davechilders

Reputation: 9123

You can use xtabs() directly on the mtcars data, without using aggregate() as an intermediate step:

xtabs(hp ~ cyl + vs, data = mtcars)

Upvotes: 1

Ryan Hope
Ryan Hope

Reputation: 512

Here is a data.table answer:

mt = as.data.table(mtcars)
dcast.data.table(mt, cyl ~ vs, value.var="hp", fun.agg = sum)

#    cyl    0   1
# 1:   4   91 818
# 2:   6  395 461
# 3:   8 2929   0

Upvotes: 1

akrun
akrun

Reputation: 887223

Try xtabs

xtabs(hp~cyl+vs, res)
  #      vs
#cyl    0    1
#  4   91  818
#  6  395  461
#  8 2929    0


res <- aggregate(hp~cyl/vs, data=mtcars, FUN=sum, na.rm=TRUE)

Upvotes: 1

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