bitwhich: A class for vectors representing asymetric selections

Description Usage Arguments Details Value Author(s) See Also Examples

View source: R/bit.R

Description

A bitwhich object like the result of which and as.which does represent integer subscript positions, but bitwhich objects represent some subscripts rather with negative integers, if this needs less space. The extreme cases of selecting all/none subscripts are represented by TRUE/FALSE. This needs less RAM compared to logical (and often less than as.which). Logical operations are fast if the selection is asymetric (only few or almost all selected).

Usage

1
bitwhich(maxindex, poslength = NULL, x = NULL)

Arguments

maxindex

the length of the vector (sum of all TRUEs and FALSEs)

poslength

Only use if x is not NULL: the sum of all TRUEs

x

Default NULL or FALSE or unique negative integers or unique positive integers or TRUE

Details

class 'bitwhich' represents a boolean selection in one of the following ways

Value

An object of class 'bitwhich' carrying two attributes

maxindex

see above

poslength

see above

Author(s)

Jens Oehlschl<c3><a4>gel

See Also

as.bitwhich, as.which, bit

Examples

1
2
 bitwhich(12, x=c(1,3), poslength=2)
 bitwhich(12, x=-c(1,3), poslength=10)

OHDSI/bit documentation built on May 9, 2017, 3:30 p.m.