[GIS] Vector data(point) is drawn in wrong place on map (OpenLayers)

Question

I need to show a map (world map, used default OpenLayers WMS) and one point on it (with events like onhover, etc). Here is my code:

                   var options = {
                            projection: new OpenLayers.Projection("EPSG:900913"),
                            maxResolution: 6000
                        };
                        map = new OpenLayers.Map('map', options);

                        var wmsLayer = new OpenLayers.Layer.WMS(
                        "OpenLayers WMS", 
                        "http://vmap0.tiles.osgeo.org/wms/vmap0",
                        {layers: 'basic'}
                    ); 

                    var vectors = new OpenLayers.Layer.Vector("Vector Layer");

                    point = new OpenLayers.Geometry.Point(20.088844299316406, 51.8321709083475);
                    vectors.addFeatures([new OpenLayers.Feature.Vector(point)]);

                    map.addLayers([wmsLayer, vectors]);

                    map.zoomToMaxExtent();

But this code locates the point is drawn not in correct place, but somewhere near Africa (that place lat and lon is 0, 0). Question: Why this happens and can I fix it? I just need to locate the point to the correct place. Paradox when I print this point in console then it shows that the point lan and lon are as needed (as defined). But it is still in the wrong place…

Answer 1

You need to translate the point from lat/lon to your map projection:

point = new OpenLayers.Geometry.Point(20.088844299316406, 51.8321709083475);    
point.transform(new OpenLayers.Projection("EPSG:4326"), map.getProjectionObject());
vectors.addFeatures([new OpenLayers.Feature.Vector(point)]);

This will transform your variable point to the map projection.