I suspect you are messing around with meaningless precision if these
numbers are coming from a spreadsheet since they are already in floating
point format there but this may do what you need:
stringToRational=: 3 : 0
if. 1=#tmp=. <;._1 '.',y do. tmp=. tmp,<,'0' end.
".(;tmp),'r1','0'$~#;1{tmp
)
stringToRational &>
'123.00';'123';'1';'1010101010.10101';'0.1';'2.';'123456789101112.1314151617'
123 123 1 101010101010101r100000 1r10 2
1234567891011121314151617r10000000000
NB. Visually verifying the ridiculous ones:
28j10":"0 ] 101010101010101r100000 1234567891011121314151617r10000000000
1010101010.1010100000
123456789101112.1314151617
On Wed, Jan 6, 2021 at 11:04 AM Henry Rich <henryhr...@gmail.com> wrote:
> For domain errors, Look at the Dissect tool.
>
> Henry Rich
>
> On 1/6/2021 3:40 AM, Justin Paston-Cooper wrote:
> > I should add how it works:
> >
> > On the right, 10^(The position of '.' in the number minus 1)
> > On the left, remove '.' and parse as number
> > In the middle, apply x: to both sides and divide.
> >
> > Also, how can I go about actually debugging domain errors? Both sides
> > seem to be zero-dimensional.
> >
> > On Wed, 6 Jan 2021 at 10:20, Justin Paston-Cooper
> > <paston.coo...@gmail.com> wrote:
> >> Thanks for the suggestion. I've combined Don's idea of using x: and
> >> your idea of removing the point and parsing that to handle all numbers
> >> of digits after the decimal point:
> >>
> >> stringToRational =: ((_&".)@(-.&'.') %&:x: 10&^@(<:@# - (i.&'.'))
> >>
> >> stringToRational '666.66' should give 333r50.
> >>
> >> Sadly this is giving a domain error, even though both sides of the
> >> fork work alone. Could anyone suggest how to fix this?
> >>
> >> On Tue, 5 Jan 2021 at 19:14, Jimmy Gauvin <jimmy.gau...@gmail.com>
> wrote:
> >>> IF your strings always have two numbers after the decimal point you
> could
> >>> remove the point before converting to numeric.
> >>>
> >>> NB.Remove decimal point
> >>> '.' -.~ each '123.45' ; '1456.12'
> >>> ┌─────┬──────┐
> >>> │12345│145612│
> >>> └─────┴──────┘
> >>>
> >>> NB. Convert to numeric
> >>> _ ". > '.' -.~ each '123.45' ; '456.12'
> >>> 12345 45612
> >>>
> >>> NB. type 4 is integer
> >>> 3!:0 ] _ ". > '.' -.~ each '123.45' ; '456.12'
> >>> 4
> >>>
> >>> On Tue, Jan 5, 2021 at 10:43 AM Justin Paston-Cooper <
> >>> paston.coo...@gmail.com> wrote:
> >>>
> >>>> Hello,
> >>>>
> >>>> I am reading in tab-separated files with readdsv from 'tables/dsv'.
> >>>> Some columns consist of exact decimal numbers like 6.66. These
> generally
> >>>> involve amounts of a decimal currency. These are read in by readdsv as
> >>>> boxed strings. makenum from 'tables/csv' converts these strings to
> >>>> floats. I would like these strings to be converted exactly to
> >>>> rationals. How can I go about this in the easiest and most efficient
> >>>> way? I could not find information on parsing data types from strings.
> >>>>
> >>>> Thanks in advance,
> >>>>
> >>>> Justin
> >>>> ----------------------------------------------------------------------
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> http://www.jsoftware.com/forums.htm
> >>>>
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--
Devon McCormick, CFA
Quantitative Consultant
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