This was already discussed recently, here on julia-users, I'm trying to get
in touch with Dahua Lin (author of Formatting.jl)
to see about adding a simpler `sfmt` that would help with this).
On Thursday, June 18, 2015 at 10:13:46 AM UTC-4, Tom Breloff wrote:
>
> 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
>>
>>
