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BC::math

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PHP bcmath as a static class, with several enhancements.

Installation

Use Composer:

composer require danhunsaker/bcmath

Usage

Usage is nearly identical to the bcmath extension functions. The main difference is that the bc prefix is replaced by the Danhunsaker\BC class name (which you can easily alias in your project(s) via use Danhunsaker\BC).

In other words:

There are also some additional convenience methods available, that aren't present in the extension:

  • BC::epow() raises e to the argument's power.
  • BC::fact() calculates the factorial of the argument.
  • BC::intval() truncates the fractional portion of the argument, if any.
  • BC::ln() gives the natural logarithm of the argument.
  • BC::log() gives the base 10 logarithm of the argument (uses ln $val/ln 10).
  • BC::max() returns the largest value in an array (the first argument).
  • BC::min() returns the smallest value in an array (the first argument).
  • BC::modfrac() behaves exactly like BC::mod(), except it will return the fractional part of any remainder as well as the integer part.
  • BC::powfrac() supports fractional exponents, allowing roots other than the square to be calculated.
  • BC::root() is a complement to BC::powfrac(), and is in fact just a convenience wrapper for it.
  • BC::round() rounds a value to a given scale.

Expression Parser

There's also BC::parse(), which lets you write your calculations as expressions instead of method calls. It doesn't (yet) support everything available via method calls, but this is planned for a later release. For the moment, here's a list of which ones are supported, and how to specify each in your expressions:

  • BC::add(a, b) => 'a + b'
  • BC::div(a, b) => 'a / b'
  • BC::div(a, b, 0) => 'a \ b'
  • BC::mod(a, b) => 'a % b'
  • BC::modfrac(a, b) => 'a %% b'
  • BC::mul(BC::div(a, b, 0), b) => 'a \* b'
  • BC::sub(a, BC::mod(a, b)) => 'a -% b'
  • BC::mul(a, b) => 'a * b'
  • BC::pow(a, b) => 'a ** b'
  • BC::powfrac(a, b) => 'a ^ b'
  • BC::sub(a, b) => 'a - b'

There are also some logical expressions available, all of which will return a boolean value (true/false) instead of a number:

  • BC::comp(a, b) == 0 => 'a = b' or 'a == b'
  • BC::comp(a, b) == 1 => 'a > b'
  • BC::comp(a, b) == -1 => 'a < b'
  • BC::comp(a, b) >= 0 => 'a >= b'
  • BC::comp(a, b) <= 0 => 'a <= b'
  • BC::comp(a, b) != 0 => 'a != b' or 'a <> b'
  • a and b => 'a & b' or 'a && b'
  • a or b => 'a | b' or 'a || b'
  • a xor b => 'a ~ b' or 'a ~~ b'

The expression parser recognizes parentheses, so you can use those to group your subexpressions as needed. It also supports variables:

BC::parse('{m} * {x} + {b}', ['m' => 0.5, 'x' => 5, 'b' => 0]);

Need to specify a scale for your expression? No problem, just pass it along in the third parameter:

BC::parse('{m} * {x} + {b}', ['m' => 0.5, 'x' => 5, 'b' => 0], 18);

You can, of course, skip the variable list by passing null as the second argument:

BC::parse('{m} * {x} + {b}', null, 18);

// Any unrecognized variables are assumed to be zero,
// so the above is the same as:

BC::parse('0 * 0 + 0', null, 18);

Contributions

Contributions are welcome at any time on GitHub.

Security issues should be reported directly to Dan Hunsaker via email.