I'm creating this rating system using 5-edged stars. And I want the heading to include the average rating. So I've created stars showing 1/5ths. Using "1.2" I'll get a full star and one point on the next star and so on...
But I haven't found a good way to round up to the closest .2... I figured I could multiply by 10, then round of, and then run a switch to round 1 up to 2, 3 up to 4 and so on. But that seems tedious and unnecessary...
round(3.78 * 5) / 5 = 3.8
A flexible solution
function roundToNearestFraction( $number, $fractionAsDecimal )
{
$factor = 1 / $fractionAsDecimal;
return round( $number * $factor ) / $factor;
}
// Round to nearest fifth
echo roundToNearestFraction( 3.78, 1/5 );
// Round to nearest third
echo roundToNearestFraction( 3.78, 1/3 );
function round2($original) {
$times5 = $original * 5;
return round($times5) / 5;
}
So your total is 25, would it be possible to not use floats and use 1->25/25? That way there is less calculations needed... (if any at all)
Why is everyone giving solutions that require a deeper inspection or conversion? Want 0.2? Then:
round($n / 0.2) * 0.2; // $n = 3.78 / 0.2 = 18.9 (=) 19 * 0.2 = 3.8 //
Want 5? Then:
round($n / 5) * 5; // $n = 17 / 5 = 3.4 (=) 3 * 5 = 15 //
It's as simple as that.
Related
I'm currently dividing two values in order to get the percentage from the actual count and the total count for my application.
I am using the following formula:
echo ($fakecount / $totalcount) * 100;
That is giving me a value like: 79.2312313. I would perefer a value like 79%.
I have tried the following:
echo round($fakecount / $totalcount) * 100;
this doesn't seem to work correctly.
Any suggestions?
You need to multiply by 100 before you round, not after:
echo round($fakecount * 100 / $totalcount);
You are calculating $fakecount / $totalcount, which will be a number between 0 and 1, then you round that, so you get either 0 or 1, then you multiply by 100, giving either 0 or 100 for your percentage.
try,
echo (int)($fakecount * 100 / $totalcount + .5);
This works because adding 0.5 increases the integer part by 1 if the decimal part is >= .5
or,
round ($fakecount * 100 / $totalcount);
Note that, I'm doing the multiplication by 100 before the division to better preserve the precision.
echo intval(($fakecount / $totalcount) * 100);
Or you can use
echo floor(($fakecount / $totalcount) * 100); //Round down
Or
echo ceil(($fakecount / $totalcount) * 100); // Round Up
use the round() function
echo round(($fakecount / $totalcount) * 100);
http://php.net/manual/en/function.round.php
others you can use are
ceil() - Round fractions up
floor() - Round fractions down
Nope...
There is a lot of ways to do it.
$mypercent = ($fakecount / $totalcount) * 100;
Remember.. this will first run what is inside of (xxx) and after will * 100.
After this...
echo round($mypercent);
And you can use a lot of rules on that too if you want...
<i>if ($value < 10) {
$value = floor($value);
} else {
$value = round($value);
}</i>
Dont forget to see that other to commands too, maybe you are going to need it.
ceil() - Round fractions up
floor() - Round fractions down
=)
I'm not sure if this title is correct but here's basically what I am trying to do.
I am trying to check if a number is less than 100 and if it isn't I would like to know what factor of 10 I need to divide it by to get below 100 i.e. for 7923 the factor is 100 to make it 79.23 and for 452,936,489 the factor would be 10,000,000 to make it 45.2936489.
Is there a function or a piece of script that does that out there?
Cheers
$number = 452936489;
$factor = pow(10, ceil(log($number/100) / log(10)));
Ok. basic math:
you need to find a power of 10 divisor that reduces your number below 100, so the log business figures out the exact fractional power of 10 required to turn 10 into your original number. That comes out to be around 6.6560373....
That gets rounded up to 7, and is then used to raise 10 to that power.
10^7 = 10,000,000
452936489 / 10^7 = 45.2936489
<?
$num = 7923;
$x = 10;
while(true)
{
$result = $num/$x;
if($result < 100)
{
die($x."");
}
else
{
$x *= 10;
}
}
?>
So, I need to create the following functions but my head can't think of any possibility in PHP without complicated math.
Round always up to the nearest decimal (1.81 = 1.90, 1.89 = 1.90, 1.85 = 1.90)
Round always down to the nearest decimal (1.81 = 1.80, 1.89 = 1.80, 1.85 = 1.80)
Round always up to the nearest x.25 / x.50 / x.75 / x.00 (1.81 = 2, 1.32 = 1.50)
Round always down to the nearest x.25 / x.50 / x.75 / x.00 (1.81 = 1.75, 1.32 = 1.25)
Round always up to the nearest x.50 / 1 (1.23 = 1.50, 1.83 = 2)
Round always down to the nearest x.50 / 1 (1.23 = 1, 1.83 = 1.50)
I have searched on Google for 2 hours now and the only things that came up were Excel forums. Is it possible with some simple lines of PHP?
Since you're looking for fourths (.00, .25, .50, .75), multiply your number by 4, round to nearest whole number as desired (floor if down, ceil if up), then divide by 4.
1.32, down to nearest fourth:
1.32 * 4 = 5.28
floor(5.28) = 5.00
5.00 / 4 = 1.25
Same principle applies for any other fractions, such as thirds or eighths (.0, .125, .25, .375, .5, .625, .75, .875). For example:
1.77, up to nearest eighth:
1.77 * 8 = 14.16
ceil(14.16) = 15.00
15.00 / 8 = 1.875
Just for fun, you could write a function like this:
function floorToFraction($number, $denominator = 1)
{
$x = $number * $denominator;
$x = floor($x);
$x = $x / $denominator;
return $x;
}
echo floorToFraction(1.82); // 1
echo floorToFraction(1.82, 2); // 1.5
echo floorToFraction(1.82, 3); // 1.6666666666667
echo floorToFraction(1.82, 4); // 1.75
echo floorToFraction(1.82, 9); // 1.7777777777778
echo floorToFraction(1.82, 25); // 1.8
Please note that the answer isn't really water tight. Since we're dealing with floats here it's not guaranteed that when you divide the rounded number by the denominator it returns a neatly round number. It may return 1.499999999999 instead of 1.5. It's the nature of floating point numbers.
Another round is needed before returning the number from the function.
Just in case someone lands here from google like I did :)
According to the mround() function in Excel:
function MRound($num,$parts) {
$res = $num * $parts;
$res = round($res);
return $res /$parts;
}
echo MRound(-1.38,4);//gives -1.5
echo MRound(-1.37,4);//gives -1.25
echo MRound(1.38,4);//gives 1.5
echo MRound(1.37,4);//gives 1.25
Look at example #3 on here and it is half of your solution - http://php.net/manual/en/function.round.php
Searching for a function ro round numbers to the nearest multiple of 5
22 -> 20
23 -> 25
40 -> 40
46 -> 45
48 -> 50
and so on.
Tried this which always returns the higher value:
5 * ceil($n / 5);
Use round() instead of ceil().
5 * round($n / 5);
ceil() rounds a floating point number up to its next integer in sequence. round() will round to the nearest integer using standard rounding rules.
Back to maths, since round works with decimals, multiply by 5 and divide by 10 and then round, it. Multiply by 5 again to get what u want. (Other answer works as well, just a different way of looking at it)
function round_5($in)
{
return round(($in*2)/10)*5;
}
echo round_5(48);
See if this helps
Well, facing this issue while helping make an POS for a Canadian company, came up with this solution, hope it helps someone. (Canada removed the penny in 2012). Also includes for doing tax included pricing, just pass '1' as second argh.
//calculate price and tax
function calctax($amt,$tax_included = NULL){
$taxa = 'tax rate 1 here';
$taxb = 'tax rate 2 here';
$taxc = ($taxa + $taxb) + 1;
if(is_null($tax_included)){
$p = $amt;
}else{
$p = number_format(round($amt / $taxc,2),2);
}
$ta = round($p * $taxa,2);
$tb = round($p * $taxb,2);
$sp = number_format(round($p+($ta + $tb),2),2);
$tp = number_format(round(($sp*2)/10,2)*5,2);
$ret = array($ta,$tb,$tp);
return $ret;
}
Is it possible to round a number where if it's .5, just leave it, anything below .5 round down, anything above .5 round up?
For example:
5.0 * 1.35 = 6.75 // leave it
5.2 * 1.35 = 7.02 // round down to 7.00
5.5 * 1.35 = 7.56 // round up to 8.00
I've formatted with round($n,0, PHP_ROUND_HALF_UP) where $n is the product from the above calc , which leaves 6.75 but returns 7.02 for the next one. I also tried round($n,-1, PHP_ROUND_HALF_UP) which gives me the 7.00 on the second calc but then of course won't return a 6.75 for the first, instead it returns 680.
This is a ticket markup calculation where the user enters the first number and is multiplied by the second. I actually remove the decimal because they don't want to see it, and they want this sort of customized rounding on the result.
function myround($num, $prec) {
$rhu = round($num, $prec, PHP_ROUND_HALF_UP);
$rhd = round($num, $prec, PHP_ROUND_HALF_DOWN);
return ($rhu + $rhd) / 2;
}
Works for any precision you like. For hundreth's place, as in the example, $prec would need to be 2.
The only way to determine the value of the last non-zero digit of a given floating point number in PHP is to convert it to a string.
$str = (string) $float;
$result = ($str[strlen($str) - 1] == 5) ? $float : round($float);
Example
Of course, no matter what you do it will be subject to a small margin of error because of the floating point precision issue.
$n = round($n, 2);
if($n % .05 != 0 || $n % .1 == 0)
{
$n = round($n);
}
Does this work for you? I'm assuming the 5 you speak of is the hundredth digit, and if it's not 5 then you want a whole number.