Fractional part of decimal value.

Wouter Beek <[email protected]>
Newsgroups gmane.comp.ai.prolog.swi
Message-ID <CAE1un7OKFHOnxWOt81-ULeBd0MaCdCxPRt6-WcHKBXqOBZAFJQ@mail.gmail.com>
Hi all,

I want to extract the integer and fractional part of a decimal value:
~~~{.pl}
decimal_parts(D, I, F):-
  I is floor(D / 1),
  F is D - I * 1.
~~~
What I get is the fractional part of the float value 1.1:
~~~
?- decimal_parts(1.1, _, F).
F = 0.10000000000000009.
~~~
I do not mind the padding zero's (just a notational difference), but I do
not need the 9 at the end.

Is there a way to get the same result as with e.g. C's modf (sample code
below)? Thanks for any suggestions!

---
Cheers,
Wouter.

Sample code in C:
~~~{.c}
#include <stdio.h>
#include <math.h>

int main() {
  double param, fractional_part, integer_part;
  param = 1.1;
  fractional_part = modf(param, &integer_part);
  printf("%f = %f + %f \n", param, integer_part, fractional_part);
  return 0;
}
~~~

Compile and run:
~~~
$ gcc -Wall test.c -o test
$ ./test
1.100000 = 1.000000 + 0.100000
~~~

E-mail: [email protected]
WWW: www.wouterbeek.com
Tel.: 0647674624
-------------- next part --------------
HTML attachment scrubbed and removed
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.