[erlang-questions] display floats without -e?
Tue Jan 1 12:10:58 CET 2019
you may add also 'compact' option for unuseful zeros.
Warning : documentation says for float_to_list/2 option 'decimals': " If
the number does not fit in the internal static buffer of 256 bytes, the
function throws badarg."
Le 01/01/2019 à 11:43, PAILLEAU Eric a écrit :
> 1> c(floaty).
> 2> floaty:auto(12.345555).
> 3> floaty:auto(12.3455553333333).
> 4> list_to_float(floaty:auto(12.3455553333333)).
> Le 31/12/2018 à 20:31, Dan Sommers a écrit :
>> On 12/31/18 10:37 AM, Vans S wrote:
>> > > 1> 0.0001.
>> > 0.0001
>> > > 2> 0.00001.
>> > 1.0e-5
>> > Once floats get to the 4th/5th decimal place they start being
>> > displayed with the e-x notation. Is there a way to make them always
>> > display "normally", for example 0.00001 in this case ...
>> At some point, it's shorter and easier to read with the e-x notation.
>> Consider a number like 1e-44. The last thing I want is to have to count
>> all those zeros. ;-)
>> But you probably knew that.
>> > ... The problem is when you turn the float into a string, its also
>> > displayed as 1.0e-5, adding a format function works yes, but gets
>> > annoying to maintain when you need to do arithmetic on the floats.
>> > LIke sorting by the value.
>> I'm confused: if you're doing arithmetic on the floats, why are you
>> concerned with the strings?
>> If you're sorting the strings, then you'll probably either (a) have to
>> ensure a consistent format, perhaps with something like a ~24.18.0e
>> specifier, or (b) convert the strings back to floats and suffer various
>> rounding errors.
>> > Also debugging becomes annoying when you see the e-5, e-6, etc
>> > notation everywhere and have to match it up.
>> On that we agree. :-)
>> > Is there a way to compile / add arg to the VM to not do this?
>> I'm pretty new at Erlang, so I'm probably missing a lot, but how are you
>> displaying the values now if not with a format function? (I guess
>> there's io:write, but at that point, you're awfully close to calling
>> io:fwrite anyway.)
>> Are you just using the shell to do immediate calculations? I'm sure
>> that the shell has its own default formatting, or maybe it just calls
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