I wonder if what we really need is just some extra additions to
Formatting.jl (since I think this is the best place to keep standard
formatting calls). We could add fmt2, fmt3, etc which would be meant for
formatting floats to that precision. I suspect that's the most common use
of formatting. Additionally, just a shorter name than "generate_formatter"
might help adoption for non-standard formatting. If this makes sense to
people, I'll start an issue on github, and perhaps a PR as well.
julia> using Formatting
julia> fmt2 = generate_formatter("%1.2f")
sprintf_JTEuMmY! (generic function with 1 method)
julia> fmt3 = generate_formatter("%1.3f")
sprintf_JTEuM2Y! (generic function with 1 method)
julia> @time fmt2(31231.345435245)
55.763 milliseconds (33974 allocations: 1444 KB)
"31231.35"
julia> @time fmt2(31231.345435245)
13.573 microseconds (15 allocations: 608 bytes)
"31231.35"
julia> @time fmt3(31231.345435245)
11.193 milliseconds (5882 allocations: 254 KB)
"31231.345"
julia> @time fmt3(31231.345435245)
16.231 microseconds (15 allocations: 608 bytes)
"31231.345"
On Thursday, June 18, 2015 at 3:55:01 AM UTC-4, cormu...@mac.com wrote:
>
> You could use a type:
>
> julia> type Out
> n::Float64
> end
>
> julia> function Base.show(io::IO, n::Out)
> print(io, "$(round(n.n, 2))")
> end
> show (generic function with 83 methods)
>
> then you can just use Out(x) whenever you want x rounded to 2 d.p.
>
> julia> for i in 0.7454539:1.5:5
> println("i is $i and displayed as $(Out(i))")
> end
> i is 0.7454539 and displayed as 0.75
> i is 2.2454539000000002 and displayed as 2.25
> i is 3.7454539000000002 and displayed as 3.75
>
>
