Medians of Columns

Compute the sample medians of the columns (non-rows) of a data.frame or array.

colMedians( x, na.rm = FALSE )

Arguments

x

a data.frame or array.

na.rm

a logical value indicating whether NA values should be stripped before the computation proceeds.

Value

A vector or array of the medians of each column (non-row) of x with dimension dim( x )[-1].

Author

Arne Henningsen

Examples

   data( "Electricity", package = "Ecdat" )
   colMedians( Electricity )
#>      cost         q        pl        sl        pk        sk        pf        sf 
#>   25.5454 5645.5000 7890.1850    0.1231   74.1200    0.2186   30.6579    0.6450 

   a4 <- array( 1:120, dim = c(5,4,3,2),
      dimnames = list( c("a","b","c","d","e"), c("A","B","C","D"),
      c("x","y","z"), c("Y","Z") ) )
   colMedians( a4 )
#> , , Y
#> 
#>    x  y  z
#> A  3 23 43
#> B  8 28 48
#> C 13 33 53
#> D 18 38 58
#> 
#> , , Z
#> 
#>    x  y   z
#> A 63 83 103
#> B 68 88 108
#> C 73 93 113
#> D 78 98 118
#> 
   median( a4[ , "B", "x", "Z" ] )  # equal to
#> [1] 68
   colMedians( a4 )[ "B", "x", "Z" ]
#> [1] 68