README

Simple math functions.

use Jstewmc\Fx;

(new Constant(1))(3);         // returns 1
(new Equality())(3);          // returns 3
(new Linear(1, 2))(3);        // returns 5 (1 * 3 + 2)
(new Quadratic(1, 2, 3))(4);  // returns 27 (1 * 4 ^ 2 + 2 * 4 + 3)
(new Power(1, 2))(3);         // returns 9 (1 * 3 ^ 2)
(new Exponential(1))(2);      // returns 1 (1 ^ 2)

This library supports the following functions:

constant, c = x
equality, y = x
linear, y = mx + b
quadratic, y = ax² + bx + c
power, y = cx^p
exponential, y = b^x

Constant

A constant function where c = x:

use Jstewmc\Fx

$fx = new Constant(1);

$fx(1);  // returns 1
$fx(2);  // returns 1
$fx(3);  // returns 1

Equality

An equality where y = x:

use Jstewmc\Fx;

$fx = new Equality();

$fx(1);  // returns 1
$fx(2);  // returns 2
$fx(3);  // returns 3

Linear

A linear function is y = mx + b, where m is the slope and b is the y-intercept:

use Jstewmc\Fx;

$fx = new Linear(1, 2);

$fx(1);  // returns 3 (1 * 1 + 2)
$fx(2);  // returns 4 (1 * 2 + 2)
$fx(3);  // returns 5 (1 * 3 + 2)

Quadratic

A univariate, standard-form quadratic function is y = ax² + bx + c, where a, b, and c are constants (aka, the quadratic coefficient, the linear coefficient, and the constant, respectively):

use Jstewmc\Fx;

$fx = new Quadratic(1, 2, 3);

$fx(1);  // returns 5 (1 * 1 ^ 2 + 2 * 1 + 3)
$fx(2);  // returns 11 (1 * 2 ^ 2 + 2 * 2 + 3)
$fx(3);  // returns 18 (1 * 3 ^ 2 + 2 * 3 + 3)

Power

A power function is y = cx^p, where c is a constant, and p is the power:

use Jstewmc\Fx;

$fx = new Power(1, 2);

$fx(1);  // returns 1 (1 * 1 ^ 2)
$fx(2);  // returns 4 (1 * 2 ^ 2)
$fx(3);  // returns 9 (1 * 3 ^ 2)

Exponential

An exponential function is y = b^x, where b is a constant:

use Jstewmc\Fx;

$fx = new Exponential(2);

$fx(1);  // returns 2 (2 ^ 1)
$fx(2);  // returns 4 (2 ^ 2)
$fx(3);  // returns 8 (2 ^ 3)

That's it!

License

MIT

Author

Jack Clayton

Version

1.0.0, August 13, 2016

Major release
Update composer.json

0.3.1, August 13, 2016

Update Fx parent class to be an interface

0.3.0, August 6, 2016

Add Fx parent class

0.2.0, August 6, 2016

Update README examples
Add Equality function
Add Constant function

0.1.0, July 30, 2016

Initial release

jstewmc / fx

Maintainers

Details