Dynamic change of html attributes with jQuery

I have this jQuery plugin - Plax: https://github.com/cameronmcefee/plax

I wanted it to be responsive, which I partly have: http://jsfiddle.net/4kRDL/

My problem is the html attributes:

<img src="/parallax/4.svg" data-xrange="20" data-yrange="10" id="plax-img4"/>
    <img src="/parallax/3.svg" data-xrange="5" data-yrange="40" id="plax-img3"/>

The problem is that the data-xrange and data-yrange isn't being responsive, and when you minimize the browser-window they have the same x-range and y-range no matter what size the window have. When minimized the ranges are to large.

So I must get size of window when it resize, then with an algorithm find xrange and yrange, and then, change the attributes with jquery and then reinitialize plaxify.

I was thinking somthing like this pseudo-code, but don't know how to do it so it works:

$('#my-element')
    .attr('data-xrange', 'New Value')
    .attr('data-yrange', 'New Value');

// You can dynamically redefine the range of a layer
// by running plaxify() on it again.
$('#my-element').plaxify();

$(window).resize(function(){
                var w = $(window).width();
                if(w > 320 && #my-element.is('New Value')) {
                    #my-element.removeAttr('data-xrange,data-yrange');
                }
            });

Solution

It's from documentation of Plax:

$('#plax-octocat').plaxify({"xRange":40,"yRange":40})
$('#plax-earth').plaxify({"xRange":20,"yRange":20,"invert":true})

$('#plax-bg').plaxify({"xRange":10,"yRange":10,"invert":true})
$.plax.enable()

$('#my-btn').click(function(){
  // bigger range
  $('#plax-octocat').plaxify({"xRange":200,"yRange":200}) // LOOK HERE
})

As you can see, if you want new xrange and yrange, then you have to set it by yourself. Then your piece of code should look something like:

$(window).resize(function(){
    var w = $(window).width();
    if(w > 320){
       $('#my-element').plaxify({"xRange":newValue,"yRange":newValue});
    }
});

EDIT: Also after changing data attributes with plaxify() you have to set CSS top and left values to 0. Something like that: http://jsfiddle.net/instead/4kRDL/14/