Remove invariable columns from a data frame or matrix

Columns with one unique value are invariable. The functions help to remove such columns from a data frame (or matrix) in order to highlight the variables.

removeInvarCol(df)

Arguments

df

A data frame or matrix

Value

isVarCol and isInvarCol return a logical vector indicating the variable and invariable columns respectively.

removeInvarCol removes invariable columns.

Details

removeInvarCol the data frame removing invariable column(s).

isVarCol and isInvarCol are helper functions, returning a logical vector indicating the variable and invariable columns respectively.

Author

Jitao David Zhang <jitao_david.zhang@roche.com>

Examples

 testDf <- data.frame(a=1:4, b=7, c=LETTERS[1:4])
isVarCol(testDf)
#>     a     b     c 
#>  TRUE FALSE  TRUE 
isInvarCol(testDf)
#>     a     b     c 
#> FALSE  TRUE FALSE 
removeInvarCol(testDf)
#>   a c
#> 1 1 A
#> 2 2 B
#> 3 3 C
#> 4 4 D