The original problem I was working on was a post on Quora ( I use these Quora math questions to help sharpen my
J skills. I try to see if I can "brute force" the solutions using J, while
most other posters try to solve these things by algebraic manipulation.  My
answer to that question is here: ( There are several
Quora problems that I have posted J solutions for, mostly to show how
simple a brute force solution can be when using an array language. You can
find those posts by searching for my name ("Skip Cave") in Quora

In this problem all I really needed to do was to find all the results from
the equation that were integers, so I used the 0=1||  scheme to find them.

Our discussion on the J forum got me thinking about finding both the
fractional part and the integer part of numbers, and I thought the pair of
verbs (fp, ip) would be a nice addition to the Phrases doc, which is
defined as listing phrases "useful to beginners in learning the language,
and of continuing use to practical programmers."

Also, when I obtained the fractional part, I wanted to keep the fact that
the fractional part came from a negative number, hence the attempt to have
negative fractional parts.


Skip Cave
Cave Consulting LLC

On Wed, Aug 9, 2017 at 9:35 AM, Martin Kreuzer <> wrote:

> From what I've gathered so far is, that people seem to not mind that much,
> when extracting the fractional part from a (negative) float, they use
>    (1&|) _8.11
> 0.89
> or
>    (1&#:) _8.11
> 0.89
> or
>    (**1||) _8.11
> _0.11
>  as long as the integer and fractional part added up produce the original
> float value.
> Q: Would somebody care to give a (scaled down) real-world example so as to
> give me a chance to understand where this ip/fp extraction usually comes
> into play and what part of the data is used for decision-making..? Thanks.
> -M
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