uniquedouble {cooltools}

Turn a 64-bit integer into a unique double value

Description

Turns 64-bit integers into unique doubles for faster comparison. The output double values are completely different from the input values.

Usage

uniquedouble(int64)

Arguments

int64

integer or vector of integers; normally used with 64-bit integers, but also works with other types.

Value

Returns a double floating point value.

Author(s)

Danail Obreschkow

Examples

# The comparison of in-built types is very fast:
int32 = as.integer(0) # (same as int32 = 0)
system.time(for(i in seq(1e4)) comparison=int32==int32)

# The comparison of 64-bit integers is very slow:
int64 = bit64::as.integer64(0)
system.time(for(i in seq(1e4)) comparison=int64==int64)

# The comparison of converted 64-bit integers is again fast:
int64d = uniquedouble(int64)
system.time(for(i in seq(1e4)) comparison=int64d==int64d)