Functions to convert between long and wide representations of data

These functions are merely wrappers for reshape. Given the complicated syntax of reshape and the particularly simple structure of this problem, the functions facilitate the conversion enormously.

to.wide(data, warn = TRUE)

Arguments

data

A Meth object.

warn

Logical. Should a warning be printed when replicates are taken as items?

Value

A data frame with the reshaped data

Details

If data represents method comparisons with exchangeable replicates within method, the transformation to wide format does not necessarily make sense.

Examples

data( milk )
str( milk )
#> 'data.frame':	90 obs. of  3 variables:
#>  $ meth: Factor w/ 2 levels "Gerber","Trig": 2 2 2 2 2 2 2 2 2 2 ...
#>  $ item: int  1 2 3 4 5 6 7 8 9 10 ...
#>  $ y   : num  0.96 1.16 0.97 1.01 1.25 1.22 1.46 1.66 1.75 1.72 ...
mw <- to.wide( milk )
str( mw )
#> 'data.frame':	45 obs. of  4 variables:
#>  $ item  : Factor w/ 45 levels "1","2","3","4",..: 1 2 3 4 5 6 7 8 9 10 ...
#>  $ repl  : Factor w/ 1 level "1": 1 1 1 1 1 1 1 1 1 1 ...
#>  $ Gerber: num  0.85 1 1 1 1.2 1.2 1.38 1.65 1.68 1.7 ...
#>  $ Trig  : num  0.96 1.16 0.97 1.01 1.25 1.22 1.46 1.66 1.75 1.72 ...
( mw <- subset( mw, as.integer(item) < 3 ) )
#>   item repl Gerber Trig
#> 1    1    1   0.85 0.96
#> 2    2    1   1.00 1.16
to.long( mw, 3:4 )
#>     meth item repl    y
#> 1 Gerber    1    1 0.85
#> 2 Gerber    2    1 1.00
#> 3   Trig    1    1 0.96
#> 4   Trig    2    1 1.16