How to truncate decimal points and convert to an integer in Julia 📂Julia

How to truncate decimal points and convert to an integer in Julia

Overview

To use the trunc function, simply pass Int as the first argument.

Code

julia> @time for t in 1:10^8
           Int64(ceil(t/1000))
       end
  0.189653 seconds

julia> @time for t in 1:10^8
           trunc(Int64, ceil(t/1000))
       end
  0.128472 seconds

The two loops perform the identical task but with about a 1.5 times speed difference. The former drops the decimal points using ceil and type casts to Int64, whereas the latter returns an integer natively using the built-in capability of the trunc function, which is faster.

People who are used to programming in other languages might find the straightforward commands like the upper loop more intuitive, but in Julia, there are many built-in functions that take a data type as the first argument to return a result, so the usage like in the lower loop will become more familiar.

Environment

OS: Windows
julia: v1.5.0