math round

[denoteone]

is there a way to round up a number to the half?  so if I had 1.26  I would get 1.5  and if I had 1.75 I get 2  that sort of thing. thanks everyone for any feedback.

[RussellReal]

and only after a floating point E.G. "."

[denoteone]

the number will always have a "." yes

[denoteone]

let me correct myself. if it is 1.6 it would go to 1.5  if it was  1.8 it would go to 2 does that make sense?

[samshel]

http://us2.php.net/manual/en/function.round.php

[RussellReal]

ok deno.. I'm putting 1 together right now..

[RussellReal]

try this.. its not tested

 

<?php
function roundP5($num) {
if ($d = stristr($num,'.')) {
	$place = substr($d,1);
	if (strlen($place) == 1) $place = $place * 10;
	$zpad = str_repeat('0',strlen($place) - 2);
	$main = stristr($d,'.',true);
	if (!$main) $main = 0;
	if ($place >= ("75".$zpad)) {
		$place = 0;
		$main++;
	}
	elseif ($place >= ("25".$zpad)) {
		$place = 5;
	} elseif ($place < ("25".$zpad)) {
		$place = 0;
	}
	return $main.$place;
}
return false;
}
?>

[laffin]

I believe ya wud have to strip the whole number and than work with the rounding for the fraction...

$num=1.74;
$fract=$num-abs($num);

 

than the easiest way is using if..else... construct

if($fract>=.75) $fract=1;
elsrif($fract>=.25) $fract=.5;
else $fract=0;

 

than add the whole number and the new fraction together

$num=abs($num)+$fract;

 

well thats the simplest I can think of at the moment;

a lot of this can be cut down significantly, but wasnt to keep example of how it can be done and still readable;

 

$num=1.24999;
$num=(abs($num))+(($fract=$num-abs($num))>=.75?1:($fract>=.26?.5:0)));

 

careful that was done off the top of my head so there maybe a missing ( or ) but ya gets the idea

 

[RussellReal]

function roundP5($num) {
if ($d = stristr($num,'.')) {
	$place = substr($d,1);
	if (strlen($place) == 1) $place = $place * 10;
	$zpad = str_repeat('0',strlen($place) - 2);
	$main = substr($num,0,strpos($num,'.',0));
	if (!$main) $main = 0;
	if ($place >= ("75".$zpad)) {
		$place = 0;
		$main = $main + 1;
	}
	elseif ($place >= ("25".$zpad)) {
		$place = 5;
	} elseif ($place < ("25".$zpad)) {
		$place = 0;
	}
	return $main.".".$place;
}
return false;
}

 

this is working.. I just tested it

[samshel]

i think i missed something...

 

this function will do the same thing ?

 

http://us2.php.net/manual/en/function.round.php

[sasa]

<?php
function my_round($num){
return round($num *2 ) / 2;
}
for ($i = 0.1; $i < 2; $i += 0.1){
echo $i, ' -> ', my_round($i), "<br />\n";
}
?>

[Psycho]

EDIT: Sasa beat me to it.

[RussellReal]

hes trying to round to .5 intervals..

 

not like

 

1.5 to 2.0

 

1.5 would be 1.5

 

1.6 would be 1.5

 

1.4 would be 1.5

 

1.2 would be 1.0

 

thats why I wrote the function, everybody knows about round()

 

EDIT::

 

oo I see what sasa did

[Psycho]

hes trying to round to .5 intervals..

 

....

 

thats why I wrote the function, everybody knows about round()

 

EDIT::

 

oo I see what sasa did

 

*** RussellReal extracts foot from mouth ***

[RussellReal]

hes trying to round to .5 intervals..

 

....

 

thats why I wrote the function, everybody knows about round()

 

EDIT::

 

oo I see what sasa did

 

*** RussellReal extracts foot from mouth ***

 

*** And then inserts directly up the rectum of mjdamato ***

[Mark Baker]

This code implements MS Excel's MROUND() function, which accepts a number to round, and a precision to round it to.

function SIGN($number) {
if ($number == 0.0) {
	return 0;
}
return $number / abs($number);
}

function MROUND($number,$multiple) {

if ((SIGN($number)) == (SIGN($multiple))) {
	$lowerVal = floor($number / $multiple) * $multiple;
	$upperVal = ceil($number / $multiple) * $multiple;
	$adjustUp = abs($number - $upperVal);
	$adjustDown = abs($number - $lowerVal) + PRECISION;
	if ($adjustDown < $adjustUp) {
		return $lowerVal;
	}
	return $upperVal;
}
return False;
}

echo MROUND(123.45,0.5);

[Psycho]

hes trying to round to .5 intervals..

 

....

 

thats why I wrote the function, everybody knows about round()

 

EDIT::

 

oo I see what sasa did

 

*** RussellReal extracts foot from mouth ***

 

*** And then inserts directly up the rectum of mjdamato ***

 

Grow up, it was just some good natured ribbing. Didn't mean to offend

 

 

@Mark Baker: You could accomplish the same thing more efficiently using the same logic Sasa provided:

function MROUND($num, $unit)
{
    if ($unit==0) { return $num; }
    $multiplier = 1 / $unit;
    return round($num * $multiplier ) / $multiplier;
}

[RussellReal]

hes trying to round to .5 intervals..

 

....

 

thats why I wrote the function, everybody knows about round()

 

EDIT::

 

oo I see what sasa did

 

*** RussellReal extracts foot from mouth ***

 

*** And then inserts directly up the rectum of mjdamato ***

 

Grow up, it was just some good natured ribbing. Didn't mean to offend

 

 

yeahhh... lol