Modify Column Names and Types

DESCRIPTION:

This function requires the bigdata library section to be loaded.

USAGE:

bd.modify.columns(data, columns=NULL, names.=NULL, types=NULL,
                   keep=NULL, drop=NULL)

REQUIRED ARGUMENTS:

OPTIONAL ARGUMENTS:

data
input data set, a bdFrame or data.frame.
columns
names or numbers of columns to be modified. If NULL, all of the columns in the input data are specified.
names.
names of output columns. If NULL, use input names. Specifying an output column name as "" will leave the corresponding input name unchanged. If this argument is shorter than the number of input columns, it is extended with "" values. If it is longer, an error is generated.
types
output column types. If NULL, use input types. Valid types are "numeric", "factor", "character", "date", or "" (to leave the input type unchanged). If this is shorter than the number of input columns, the values are repeated. If it is longer, or if its length does not divide the number of input columns evenly, an error is generated.
keep
columns to be output. If NULL and drop is NULL, select all columns.
drop
columns to be excluded from the output. All other column will be output. Ignored if keep is specified.

VALUE:

an object of class "bdFrame" or "data.frame", (the same class as data), with the new specified types, names and select columns.

EXAMPLES:

# Rename fuel.frame's columns to as.character(1:5)
bd.modify.columns(fuel.frame, names(fuel.frame), as.character(1:5))

# Make Disp. a factor column
bd.modify.columns(fuel.frame, "Disp.", types="factor")

# Eliminate Weight column
bd.modify.columns(fuel.frame, keep=2:5)