Contract data into pattern-frequency format
contract.Rdcontract() contracts data into pattern-frequency format, similar
to a contatenation of table() (or xtabs) and
as.data.frame(). Yet it uses much less memory if patterns
are sparse, because it does not create rows for patterns that do not occur.
Usage
contract(x,...)
# S3 method for data.frame
contract(x,by=NULL, weights=NULL,name="Freq",
force.name=FALSE,sort=FALSE,drop.na=TRUE,...)
# S3 method for data.set
contract(x,by=NULL, weights=NULL,name="Freq",
force.name=FALSE,sort=FALSE,drop.na=TRUE,...)Arguments
- x
an object of class
"data.frame"or"data.set".- by
the formula or a vector of variable names (quoted or not quoted). Specifies the patterns (and optionally weights). If
byis a formula, then the right-hand side specifies the variables the value patterns of which are counted. If the left-hand side of the formula is (the name of) a numeric vector, its values are used as weights (in which case theweightsargument will be ignored.) If the left-hand side of the formula is (the name of) a factor, counts are computed in separate columns for each of its levels.- weights
a numeric vector of weights or
NULL.- name
a character string, the name of the variable that containts the frequency counts of the value patterns.
- force.name
a logical value, defaults to
FALSE. IfTRUEand the left-hand side ofbyformula is a factor, the names of the columns with the counts are combinations of the labels of the factor levels and the argument ofname; ifFALSE, the column names are created from the labels of the factor levels only.- sort
a logical value, defaults to
FALSE. IfTRUE, the resulting data set is sorted by the variables that define the patterns. IfFALSE, the row of the resulting data frame or data set are ordered according to the occurrence of the patterns.- drop.na
a logical value, defaults to
TRUE. IfFALSE, patterns that involveNAare included in the resulting data frame or data set.- ...
further arguments, passed to methods or ignored.
Value
If x is a data fame, the value of contract() is also a
data frame. If it is a "data.set" object, the result is also a
"data.set" object.
Examples
iris_ <- sample(iris,size=nrow(iris),replace=TRUE)
w <- rep(1,nrow(iris_))
contract(iris[4:5])
#> Petal.Width Species Freq
#> 1 0.2 setosa 29
#> 2 0.4 setosa 7
#> 3 0.3 setosa 7
#> 4 0.1 setosa 5
#> 5 0.5 setosa 1
#> 6 0.6 setosa 1
#> 7 1.4 versicolor 7
#> 8 1.5 versicolor 10
#> 9 1.3 versicolor 13
#> 10 1.6 versicolor 3
#> 11 1.0 versicolor 7
#> 12 1.1 versicolor 3
#> 13 1.8 versicolor 1
#> 14 1.2 versicolor 5
#> 15 1.7 versicolor 1
#> 16 2.5 virginica 3
#> 17 1.9 virginica 5
#> 18 2.1 virginica 6
#> 19 1.8 virginica 11
#> 20 2.2 virginica 3
#> 21 1.7 virginica 1
#> 22 2.0 virginica 6
#> 23 2.4 virginica 3
#> 24 2.3 virginica 8
#> 25 1.5 virginica 2
#> 26 1.6 virginica 1
#> 27 1.4 virginica 1
contract(iris[4:5],sort=TRUE)
#> Petal.Width Species Freq
#> 1 0.1 setosa 5
#> 2 0.2 setosa 29
#> 3 0.3 setosa 7
#> 4 0.4 setosa 7
#> 5 0.5 setosa 1
#> 6 0.6 setosa 1
#> 7 1.0 versicolor 7
#> 8 1.1 versicolor 3
#> 9 1.2 versicolor 5
#> 10 1.3 versicolor 13
#> 11 1.4 versicolor 7
#> 12 1.5 versicolor 10
#> 13 1.6 versicolor 3
#> 14 1.7 versicolor 1
#> 15 1.8 versicolor 1
#> 16 1.4 virginica 1
#> 17 1.5 virginica 2
#> 18 1.6 virginica 1
#> 19 1.7 virginica 1
#> 20 1.8 virginica 11
#> 21 1.9 virginica 5
#> 22 2.0 virginica 6
#> 23 2.1 virginica 6
#> 24 2.2 virginica 3
#> 25 2.3 virginica 8
#> 26 2.4 virginica 3
#> 27 2.5 virginica 3
contract(iris[4:5],weights=w,sort=TRUE)
#> Petal.Width Species Freq
#> 1 0.1 setosa 5
#> 2 0.2 setosa 29
#> 3 0.3 setosa 7
#> 4 0.4 setosa 7
#> 5 0.5 setosa 1
#> 6 0.6 setosa 1
#> 7 1.0 versicolor 7
#> 8 1.1 versicolor 3
#> 9 1.2 versicolor 5
#> 10 1.3 versicolor 13
#> 11 1.4 versicolor 7
#> 12 1.5 versicolor 10
#> 13 1.6 versicolor 3
#> 14 1.7 versicolor 1
#> 15 1.8 versicolor 1
#> 16 1.4 virginica 1
#> 17 1.5 virginica 2
#> 18 1.6 virginica 1
#> 19 1.7 virginica 1
#> 20 1.8 virginica 11
#> 21 1.9 virginica 5
#> 22 2.0 virginica 6
#> 23 2.1 virginica 6
#> 24 2.2 virginica 3
#> 25 2.3 virginica 8
#> 26 2.4 virginica 3
#> 27 2.5 virginica 3
contract(iris,by=c(Petal.Width,Species),sort=TRUE)
#> Petal.Width Species Freq
#> 1 0.1 setosa 5
#> 2 0.2 setosa 29
#> 3 0.3 setosa 7
#> 4 0.4 setosa 7
#> 5 0.5 setosa 1
#> 6 0.6 setosa 1
#> 7 1.0 versicolor 7
#> 8 1.1 versicolor 3
#> 9 1.2 versicolor 5
#> 10 1.3 versicolor 13
#> 11 1.4 versicolor 7
#> 12 1.5 versicolor 10
#> 13 1.6 versicolor 3
#> 14 1.7 versicolor 1
#> 15 1.8 versicolor 1
#> 16 1.4 virginica 1
#> 17 1.5 virginica 2
#> 18 1.6 virginica 1
#> 19 1.7 virginica 1
#> 20 1.8 virginica 11
#> 21 1.9 virginica 5
#> 22 2.0 virginica 6
#> 23 2.1 virginica 6
#> 24 2.2 virginica 3
#> 25 2.3 virginica 8
#> 26 2.4 virginica 3
#> 27 2.5 virginica 3
contract(iris,by=~Petal.Width+Species)
#> Petal.Width Species Freq
#> 1 0.2 setosa 29
#> 2 0.4 setosa 7
#> 3 0.3 setosa 7
#> 4 0.1 setosa 5
#> 5 0.5 setosa 1
#> 6 0.6 setosa 1
#> 7 1.4 versicolor 7
#> 8 1.5 versicolor 10
#> 9 1.3 versicolor 13
#> 10 1.6 versicolor 3
#> 11 1.0 versicolor 7
#> 12 1.1 versicolor 3
#> 13 1.8 versicolor 1
#> 14 1.2 versicolor 5
#> 15 1.7 versicolor 1
#> 16 2.5 virginica 3
#> 17 1.9 virginica 5
#> 18 2.1 virginica 6
#> 19 1.8 virginica 11
#> 20 2.2 virginica 3
#> 21 1.7 virginica 1
#> 22 2.0 virginica 6
#> 23 2.4 virginica 3
#> 24 2.3 virginica 8
#> 25 1.5 virginica 2
#> 26 1.6 virginica 1
#> 27 1.4 virginica 1
contract(iris,by=w~Species)
#> Species Freq
#> 1 setosa 50
#> 2 versicolor 50
#> 3 virginica 50
library(MASS)
contract(housing,
by=Sat~Infl+Type+Cont,
weights=Freq)
#> Infl Type Cont Low Medium High
#> 1 Low Tower Low 21 21 28
#> 2 Medium Tower Low 34 22 36
#> 3 High Tower Low 10 11 36
#> 4 Low Apartment Low 61 23 17
#> 5 Medium Apartment Low 43 35 40
#> 6 High Apartment Low 26 18 54
#> 7 Low Atrium Low 13 9 10
#> 8 Medium Atrium Low 8 8 12
#> 9 High Atrium Low 6 7 9
#> 10 Low Terrace Low 18 6 7
#> 11 Medium Terrace Low 15 13 13
#> 12 High Terrace Low 7 5 11
#> 13 Low Tower High 14 19 37
#> 14 Medium Tower High 17 23 40
#> 15 High Tower High 3 5 23
#> 16 Low Apartment High 78 46 43
#> 17 Medium Apartment High 48 45 86
#> 18 High Apartment High 15 25 62
#> 19 Low Atrium High 20 23 20
#> 20 Medium Atrium High 10 22 24
#> 21 High Atrium High 7 10 21
#> 22 Low Terrace High 57 23 13
#> 23 Medium Terrace High 31 21 13
#> 24 High Terrace High 5 6 13
contract(housing,
by=Sat~Infl+Type+Cont,
weights=Freq,
name="housing",force.name=TRUE
)
#> Infl Type Cont housing.Low housing.Medium housing.High
#> 1 Low Tower Low 21 21 28
#> 2 Medium Tower Low 34 22 36
#> 3 High Tower Low 10 11 36
#> 4 Low Apartment Low 61 23 17
#> 5 Medium Apartment Low 43 35 40
#> 6 High Apartment Low 26 18 54
#> 7 Low Atrium Low 13 9 10
#> 8 Medium Atrium Low 8 8 12
#> 9 High Atrium Low 6 7 9
#> 10 Low Terrace Low 18 6 7
#> 11 Medium Terrace Low 15 13 13
#> 12 High Terrace Low 7 5 11
#> 13 Low Tower High 14 19 37
#> 14 Medium Tower High 17 23 40
#> 15 High Tower High 3 5 23
#> 16 Low Apartment High 78 46 43
#> 17 Medium Apartment High 48 45 86
#> 18 High Apartment High 15 25 62
#> 19 Low Atrium High 20 23 20
#> 20 Medium Atrium High 10 22 24
#> 21 High Atrium High 7 10 21
#> 22 Low Terrace High 57 23 13
#> 23 Medium Terrace High 31 21 13
#> 24 High Terrace High 5 6 13