Transformations of Response or Input Variables
ptrafo(data, numeric_trafo = id_trafo, factor_trafo = ff_trafo,
ordered_trafo = of_trafo, surv_trafo = logrank_trafo,
var_trafo = NULL)
ff_trafo(x)
an object of class data.frame
.
a function to by applied to numeric
elements of data
returning a matrix with nrow(data)
rows and an arbitrary number of columns.
a function to by applied to ordered
elements of data
returning a matrix with nrow(data)
rows and an arbitrary number of columns (usually some scores).
a function to by applied to factor
elements of data
returning a matrix with nrow(data)
rows and an arbitrary number of columns (usually a dummy or contrast
matrix).
a function to by applied to
elements of class Surv
of data
returning a
matrix with nrow(data)
rows and an arbitrary number of columns.
an optional named list of functions to be applied to the
corresponding variables in data
.
a factor
A named matrix with nrow(data)
rows and
arbitrary number of columns.
trafo
applies its arguments to the elements of data
according to the classes of the elements. See Transformations
for more documentation and examples.
In the presence of missing values, one needs to make sure that all user-supplied functions deal with that.
# NOT RUN {
### rank a variable
ptrafo(data.frame(y = 1:20),
numeric_trafo = function(x) rank(x, na.last = "keep"))
### dummy coding of a factor
ptrafo(data.frame(y = gl(3, 9)))
# }
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