Is there a PHP library/class for manipulating units & quantities?

class, php, units-of-measurement

Solution

Zend Framework 1 did inlcude a component called `Zend_Measure` which is quite sophisticated but was dropped from Zend Framework 2.

Problem

I am looking for a PHP library/class to manipulate units and quantities in a similar way to what the `ruby-units` gems does. I have found a port of that Ruby library to JavaScript called `js-quantities`, but not to PHP. Are there any PHP libraries/classses for manipulating units & quantities out there?

Original source