Simple Math Question

[crewchiefpro6]

Is there a foxpro function that will determine if a number can be divided by 2 and not have a fraction?

I know my high school math teacher is probably rolling over in his grade because I am quite sure I used to know this.


Don Higgins

http://www.crewchiefpro.com

 

[teresas]

Don,

It's MOD().

Teresa

 

[crewchiefpro6]

I knew it, I was just testing using % which is the same thing, thank you.



Don Higgins

http://www.crewchiefpro.com

 

[Olaf Doschke]

If you really jsut need to know if a number is odd or even, bittest(n,0) will be much faster than mod(n,2) or n%2, as mod(n,2) is of course more general. The result of bittest is of course not the rest/fraction, but a boolean value stating is_odd=T/F.

Bye, Olaf.

 

[alvechurchdata]

I was going to warn that the Bittest() will only work with integers but it seems to work with floating point numbers too.

Bittest(12.34, 0) returns .F telling us that 12 is not odd,

Bittest(1.23, 0) returns .T. to say that 1 is odd.

Geoff Franklin

http://www.alvechurchdata.co.uk

 

[thatguy]

was just playing aroud and noticed that, yes:

BITTEST(12.1,0) = .f.
BITTEST(12.2,0) = .f.
BITTEST(12.5,0) = .f.
BITTEST(12.9,0) = .f.

proving that 12 is even.. but

BITTEST(12.9999999999999999,0) = .T.

the system capacities help page (field characteristics) says Digits of precision in numeric computations is 16, which i guess means vfp will round up on the 16th decimal place (put 15 9's after the decimal and the return is .f.). granted, i'm no math wiz, but i would think that the 12 would be included in the number of digits?

eh, food for thought..

-- frank~

 

[Olaf Doschke]

you might also check BITAND(). Spoiler: yes it has it's problems with floating point numbers too. Perhaps use INT() or CEILING() or FLOOR() beforehand...

Bye, Olaf.