Is there a quicker floating point 'MOD' function?

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WLGfx

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Posted: 17th Aug 2011 00:00

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I've done this temporarily:

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function fmod(a#,b#)
    while a# >= b#
        a# = a# - b#
    endwhile
endfunction a#

Does anyone know a quicker way?

The built in 'MOD' only works with integers...

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IanM

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Posted: 17th Aug 2011 01:03

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function fmod(a as float, b as float)
    local v as float
    v = a - (int(a / b) * b)
endfunction v

You may need to tweak it to get the responses you require when you include negatives though.

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WLGfx

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Posted: 17th Aug 2011 01:29

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I am including negative numbers and done a bit of googling so I'm hoping it will work. Cheers...

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WLGfx

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Posted: 17th Aug 2011 01:40 Edited at: 17th Aug 2011 02:23

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+ Code Snippet

// Mathematics: $a (mod $b)
// Java: $a % $b
function modulus( $a, $b )
{
    if( $a < 0 )
    {
        return $b - ( abs( $a ) % $b );
    }
    else
    {
        return $a % $b;
    }
}

I'll implement this into your code IanM... Thanks...

EDIT: Going to finish up what I was doing then try out this...

+ Code Snippet

function fmod(a as float,b as float)
    local v as float
    
    if a < 0
        a = abs( a )
        v = b - ( a - int( a / b ) * b )
    else
        v =     ( a - int( a / b ) * b )
    endif
endfunction v

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WLGfx

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Posted: 17th Aug 2011 23:41

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Nope the above function didn't work, but I did get my program working anyway by adding the most negative value to the current value (extents) making all results a positive...

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Neuro Fuzzy

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Posted: 18th Aug 2011 06:47 Edited at: 18th Aug 2011 06:49

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Quote: "The built in 'MOD' only works with integers..."

Huh? I could have sworn it works with floats, and I thought I had tested this out before...

[edit]
also, I don't think % is the modulo operator in DBPro, maybe %% is. Type in "mod" instead. so instead of 3.4%1, type 3.4 mod 1

sorry I can't test this out right now :\

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zenassem

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Posted: 18th Aug 2011 10:53

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As Neuro Fuzzy said, It appears the built in MOD works with floats. Unless I am missing something in my test. And handles negative ints

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a#= 12.5 mod 2.2
b#= -8.43 mod 5.12
c#= 100.553 mod -8.641
    print a#
    print b#
    print c#
wait key

Your signature has been erased by a mod please reduce it to 600 x 120.

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WLGfx

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Posted: 18th Aug 2011 13:05

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It does work!

Very likely when I tried it the other day I did something silly like a typo and was only getting integer values. I just tried it now on a blank page and it is '%%' that also work.

Thanks... (even after removing tons of typos from my program I didn't go back and check that one)