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Expected Frequencies

Source: R/expFreq.R
expFreq.Rd

Calculate the expected frequencies of an n-way table assuming independence.

Usage

expFreq(x, freq = c("abs", "rel"))

Arguments

x

a table

freq

whether absolute or relative frequencies are computed. Must be "abs" or "rel"; partial matching is supported.

Value

a table with either the absolute or the relative expected frequencies, of the same dimension and dimnames as x

Details

Expected values for a 2-dimensional table can be easily calculated with res <- [chisq.test](x) and accessed by res$expected. This approach fails for higher dimensional tables, for which there is no support. expFreq() also returns expected frequencies for higher dimensional tables.

Note

Based on code by David Meyer previously published as independence_table in vcd, adapted to conform to package standards.

See also

chisq.test()

Other frequency: freq(), freq2D(), percTable(), tOne()

Examples


expFreq(Titanic)
#> , , Age = Child, Survived = No
#> 
#>       Sex
#> Class         Male      Female
#>   1st    8.5690577   2.3266650
#>   2nd    7.5144045   2.0403062
#>   3rd   18.6146300   5.0542323
#>   Crew  23.3342033   6.3356878
#> 
#> , , Age = Adult, Survived = No
#> 
#>       Sex
#> Class         Male      Female
#>   1st  164.4630158  44.6548916
#>   2nd  144.2214139  39.1589050
#>   3rd  357.2642744  97.0041646
#>   Crew 447.8454431 121.5987049
#> 
#> , , Age = Child, Survived = Yes
#> 
#>       Sex
#> Class         Male      Female
#>   1st    4.0889933   1.1102408
#>   2nd    3.5857326   0.9735958
#>   3rd    8.8825516   2.4117847
#>   Crew  11.1346433   3.0232711
#> 
#> , , Age = Adult, Survived = Yes
#> 
#>       Sex
#> Class         Male      Female
#>   1st   78.4786606  21.3084751
#>   2nd   68.8197485  18.6858936
#>   3rd  170.4797980  46.2885645
#>   Crew 213.7034295  58.0246169
#> 

expFreq(UCBAdmissions, freq="r")
#> , , Dept = A
#> 
#>           Gender
#> Admit            Male     Female
#>   Admitted 0.04752573 0.03240792
#>   Rejected 0.07503920 0.05116943
#> 
#> , , Dept = B
#> 
#>           Gender
#> Admit            Male     Female
#>   Admitted 0.02979909 0.02032008
#>   Rejected 0.04705030 0.03208373
#> 
#> , , Dept = C
#> 
#>           Gender
#> Admit            Male     Female
#>   Admitted 0.04676165 0.03188689
#>   Rejected 0.07383279 0.05034677
#> 
#> , , Dept = D
#> 
#>           Gender
#> Admit            Male     Female
#>   Admitted 0.04034339 0.02751026
#>   Rejected 0.06369887 0.04343643
#> 
#> , , Dept = E
#> 
#>           Gender
#> Admit            Male     Female
#>   Admitted 0.02974815 0.02028534
#>   Rejected 0.04696988 0.03202888
#> 
#> , , Dept = F
#> 
#>           Gender
#> Admit            Male     Female
#>   Admitted 0.03637017 0.02480092
#>   Rejected 0.05742550 0.03915860
#>