uniquedouble: Turn a 64-bit integer into a unique double value
In docore: Utility Functions for Scientific Coding

Description Usage Arguments Value Author(s) Examples

View source: R/uniquedouble.R

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

1	uniquedouble(int64)

int64

input value (normally used with 64-bit integers, but also works with other types)

Returns a double floating point value.

Danail Obreschkow

# 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)