yearOf() Extract the year from an ISO date. Function for Simile - Exhibit

Simile - yearOf

<script>
$(document).bind("scriptsLoaded.exhibit", function() {
    Exhibit.FunctionUtilities.registerSimpleMappingFunction("yearOf",
        function(d) {
            return d.split('-')[0];
            },
        "number");
       });
</script>