Matrix.utils (version 0.5)

aggregate.Matrix: Compute summary statistics of a Matrix.

Description

Similar to aggregate. Splits the matrix into groups as specified by groupings, which can be one or more variables. Aggregation function will be applied to all columns in data, or as specified in formula. Warning: groupings will be made dense if it is sparse, though data will not.

Usage

## S3 method for class 'Matrix':
aggregate(x, groupings = NULL, form = NULL, fun = "sum",
  ...)

Arguments

x

a Matrix or matrix-like object

groupings

an object coercible to a group of factors defining the groups

form

formula

fun

name of aggregation function to be applied to all columns in data

...

arguments to be passed to or from methods. Currently ignored

See Also

summarise summarise aggregate

Examples

skus<-Matrix(as.matrix(data.frame(
   orderNum=sample(1000,10000,TRUE),
   sku=sample(1000,10000,TRUE),
   amount=runif(10000))),sparse=TRUE)
a<-aggregate.Matrix(skus[,'amount'],skus[,'sku',drop=FALSE])

m<-rsparsematrix(1000000,100,.001)
labels<-as.factor(sample(1e4,1e6,TRUE))
b<-aggregate.Matrix(m,labels)

orders<-data.frame(orderNum=as.factor(sample(1e6, 1e7, TRUE)),
   sku=as.factor(sample(1e3, 1e7, TRUE)),
   customer=as.factor(sample(1e4,1e7,TRUE)),
   state = sample(letters, 1e7, TRUE), amount=runif(1e7))
system.time(d<-aggregate.Matrix(orders[,'amount',drop=FALSE],orders$orderNum))