_trackEvent(\'category\', \'action\', \'label\', value, noninteraction); // Event Tracking - Web Tracking (ga.js)
//or
ga(\'send\', \'event\', \'category\', \'action\', \'label\', value); // Event Tracking - Universal Analytics Tracking (analytics.js)
/*
value is a number and nonteraction is boolean. Now convert them to piwik as following way
*/
_paq.push([\'trackEvent\', \'category\', \'action\', \'name\', value]);