Google Analytics Page Speed Implementation - google-analytics

Question

I am wondering how to implement correctly google analytics page speed measurements and how to change the sample size correctly:
As seen below in the code box we currently Google analytics including eCommerce running on our site. Now I would like to also increase the sample sizeof speed tracking (the percentage of pageviews used for speedtracking, usually 1%) to 100% on our staging system.
As far as I understood I can do that by following this instructions.
My question not is if I just add it to the existing create method in my analytics snippet or do I have to create another method below.
If I understood correctly I would now do this:
replace
ga('create', 'UA-XXXXXXX-1', 'ricomprostaging.it');
with
ga('create', 'UA-XXXXXXX-1', {'sampleRate': 5}, 'ricomprostaging.it');
Please advise if I am on the right track. I have placed the entire code of the current snippet below.
Thank you,
Fabian
<script>
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','//www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-XXXXXXX-1', 'ricomprostaging.it');
ga('send', 'pageview');
ga('send', 'pageview', 'search_query');
ga('require', 'ecommerce', 'ecommerce.js');
function trackEcommerce() {
this._addTrans = addTrans;
this._addItem = addItems;
this._trackTrans = trackTrans;
}
function addTrans(orderID,store,total,tax,shipping,city,state,country) {
ga('ecommerce:addTransaction', {
'id': orderID,
'affiliation': store,
'revenue': total,
'tax': tax,
'shipping': shipping,
'city': city,
'state': state,
'country': country
});
}
function addItems(orderID,sku,product,variation,price,qty) {
ga('ecommerce:addItem', {
'id': orderID,
'sku': sku,
'name': product,
'category': variation,
'price': price,
'quantity': qty
});
}
function trackTrans() {
ga('ecommerce:send');
}
var pageTracker = new trackEcommerce();
</script>

Answer 1

Yes you need to replace the create statement on all pages. However sampleRate is the wrong option: this option defines the sample rate for Google Analytics as a whole. For sampling speed, you want to use siteSpeedSampleRate. As for the code, I would use the following:
ga('create', 'UA-XXXXXXX-1', {
'siteSpeedSampleRate': 5,
'cookieDomain': 'ricomprostaging.it'
});