freegroup (version 1.1-6)

subs: Substitute and invert symbols

Description

Substitute and invert specific symbols in a free object

Usage

subs(a, from, to)
flip(a, turn)

Arguments

a

Object of class free

from,to,turn

Objects coerced to class free specifying symbols to alter. These arguments are coerced to symbols using getlet(as.free())

Author

Robin K. S. Hankin

Details

Function subs(a,from,to) takes object a and transforms every symbol present in from into the symbol specified in to.

Function flip(a,turn) takes object a and replaces every symbol present in turn with its inverse.

Function discard(), documented at keep.Rd, effectively substitutes a symbol with the identity element (thereby discarding it).

See Also

abs,discard

Examples

subs(abc(1:10),abc(5),'z')
flip(abc(1:10),abc(5))


o <- rfree(30,5,10)

# Following tests should all be TRUE:
size(flip(o,'a'))   == size(o)
number(flip(o,'a')) == number(o)
total(flip(o,'a'))  == total(o)

size(subs(o,'a','b'))   <= size(o)
number(subs(o,'a','b')) <= number(o)
total(subs(o,'a','b'))  <= total(o)