Format->Parse of Infix-Expression fails about mathnet-symbolics HOT 6 CLOSED

A dirty hack solution I used for now (Infix.fs lline 176):

| Approximation (Approximation.Real fp) ->
            if fp >= 0.0 then write (fp.ToString("0.#########").Replace(".","§"))
            else
                if priority > 0 then write "("
                write (fp.ToString("0.#########").Replace(".","§"));
                if priority > 0 then write ")"

On the other side then § has to be replaced back to . again of course.

This shows one way to deal with this issue, namely to force it to not use the exponential notation. However this often results in much longer string lengths, so I guess a change in the parser that takes into account the format of the Invariant culture will be necessary in the end.

Best regards,
Patrick

from mathnet-symbolics.

Thanks for reporting this. Yes, format and parse are supposed to be symmetric (expect for some loss of precision when using approximations - but that's ok since they are approximations after all).

from mathnet-symbolics.

(slightly related: #29)

from mathnet-symbolics.

It seems, it's can be easy to fix if add one parameter for options:

Just use

        let options = 
            NumberLiteralOptions.AllowFraction 
            ||| NumberLiteralOptions.AllowFractionWOIntegerPart 
            ||| NumberLiteralOptions.AllowInfinity
            ||| NumberLiteralOptions.AllowExponent

instead of

let options = NumberLiteralOptions.AllowFraction ||| NumberLiteralOptions.AllowFractionWOIntegerPart ||| NumberLiteralOptions.AllowInfinity

in the Infix.fs#L57
(not tested yet)

from mathnet-symbolics.

Indeed, this is elegant and also fixes it. Thank you!

from mathnet-symbolics.

This seems to be fixed now in master and the next release. Thanks!

from mathnet-symbolics.