Changing a single jQuery plugin option on window resize
$(window).smartresize(function () {

  var chosenSettings;

  // We could map out the defaults first.
  var defaults = {
    accordionW: config.wWidth,
    accordionH: config.wHeight,
    visibleSlices: 0,
    expandedHeight: 600,
    expandedWidth: 1000,
    contentAnimSpeed: 200
  };

  // Then, depending on the conditions, create an object of the modifications
  // This way, it's easier to add in more differences.
  if (config.wWidth &gt;= 768 &amp;&amp; config.wWidth &lt;= 1024) {
    chosenSettings = {visibleSlices: 2};
  } else if (config.wWidth &lt; 768) {
    chosenSettings = {visibleSlices: 1};
  } else {
    chosenSettings = {visibleSlices: 3};
  }

  // Then use extend to create an object with the chosen settings
  var settings = $.extend({}, defaults, chosenSettings);
  $('#va-accordion').vaccordion(settings);  

// Assuming smartresize returns the same object, we can chain trigger.
}).trigger('smartresize');