I am using a angular directive where I at one point assigns the function scalePoint (with parameters) using the parentheseless syntax. It seems like my function that I am assigning don't have access to anything that is not part of the scope of the function or that is passed as parameters. See example:

```
var Map = (function () {
    function Map(dataService, common, mapboxToken) {
        var _this = this;
        this.map = null;
    }

Map.prototype.initMap = function () {
    var _this = this;
    // Map is initalized, (code omitted)
    dataService.loadData().then(function (data) {
        var geoLayer = L.geoJson(data, {
            pointToLayer: _this.scalePoint // function assigned
        });
    });
};

Map.prototype.scalePoint = function (feature, latlng) {
    var zoom = this.map.getZoom(); // Map is undefined
    return L.circleMarker(latlng, {
        color: "#fff"
    });
};

```

When I try to use my map variable it is undefined, I guess I could pass the map as a parameter to the scalePoint function, but I do not know how to do that. I am also wondering how it gets the values for "feature" and "latlng", all I know is that they are a part of data.