# PHP Calc

The CLI calculator you never knew you needed. Also usable as a library!

## Usage

### CLI

Call with an expression to evaluate:

    $ calc "42*atan(pi/2)"
    42.163162517863

Or call without arguments to go interactive:

    $ calc
    ~ 42*atan(pi/2)
      42.163162517863

### Library 

As simple as falling off a rock:

    use NoccyLabs\PhpCalc\Calculator;
    
    $calc = new Calculator();
    $result = $calc->evaluate("42 * atan(pi/2)");

## What it does

Supported operations:

* `+` addition
* `-` subtraction
* `*` multiplication
* `/` division
* `^` exponent/raise to power

Supported functions:

* abs
* acos
* acosh
* asin
* asin
* atan
* atanh
* ceil
* cos
* cosh
* floor
* sin
* sinh
* log
* round
* sqrt
* tan
* tanh

Constants:

* `pi` 

## Useful tips

* You can set the precision using the `_p` variable. If the expression is passed on the
  command line, prepend the variable followed by a semicolon, such as `_p=2;pi` for the
  result *3.14*.

## Bugs and known issues

* Negative numbers and subtraction should be surrounded by whitespace to parse properly.
  Passing `2-1` will result in `2` and `-1`, returning *2* and a warning. Passing
  `2 - 1` will return `1` as expected, as will `2- 1`.