Provides a function to rescale numbers so that the range [a,b] fits into the range [c,d].
<?php
function rescale($ab, $cd)
{
list($a, $b) = $ab;
list($c, $d) = $cd;
if($a == $b)
{
trigger_error("Invalid scale", E_USER_WARNING);
return false;
}
$o = ($b * $c - $a * $d) / ($b - $a);
$s = ($d - $c) / ($b - $a);
return function($x)use($o, $s)
{
return $s * $x + $o;
};
}
$fahr2celsius = rescale([32, 212], [0, 100]);
echo $fahr2celsius(98.6); // 37°C
?>
Mathematical Functions
- Giriş
- Yapılandırma/Kurulum
- Öntanımlı Sabitler
- Math İşlevleri
- abs — Absolute value
- acos — Arc cosine
- acosh — Inverse hyperbolic cosine
- asin — Arc sine
- asinh — Inverse hyperbolic sine
- atan2 — Arc tangent of two variables
- atan — Arc tangent
- atanh — Inverse hyperbolic tangent
- base_convert — Convert a number between arbitrary bases
- bindec — Binary to decimal
- ceil — Round fractions up
- cos — Cosine
- cosh — Hyperbolic cosine
- decbin — Decimal to binary
- dechex — Decimal to hexadecimal
- decoct — Decimal to octal
- deg2rad — Converts the number in degrees to the radian equivalent
- exp — Calculates the exponent of e
- expm1 — Returns exp($num) - 1, computed in a way that is accurate even when the value of number is close to zero
- fdiv — Divides two numbers, according to IEEE 754
- floor — Round fractions down
- fmod — Returns the floating point remainder (modulo) of the division of the arguments
- hexdec — Hexadecimal to decimal
- hypot — Calculate the length of the hypotenuse of a right-angle triangle
- intdiv — Integer division
- is_finite — Checks whether a float is finite
- is_infinite — Checks whether a float is infinite
- is_nan — Checks whether a float is NAN
- log10 — Base-10 logarithm
- log1p — Returns log(1 + number), computed in a way that is accurate even when the value of number is close to zero
- log — Natural logarithm
- max — Find highest value
- min — Find lowest value
- octdec — Octal to decimal
- pi — Get value of pi
- pow — Exponential expression
- rad2deg — Converts the radian number to the equivalent number in degrees
- round — Rounds a float
- sin — Sine
- sinh — Hyperbolic sine
- sqrt — Square root
- tan — Tangent
- tanh — Hyperbolic tangent
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User Contributed Notes 1 note
Hayley Watson ¶
11 years ago
