Hello I'm an artist trying different ways of drawing contours in QGIS using points with income values. I've been able to import a shp file with the data, create a layer with centroids of the census blocks and create contours using the contours plugin but they're not smooth.
So then I tried creating the contours from an IDW raster but couldn't get the contours to work using extraction->contour.
How can I make the contours using extraction->contour? How can I make them smooth? I'm trying to create a 10 layer contour map of income in NYC which is accurate and smooth. What's the best way to do this in QGIS without GRASS (had issues using it in QGIS) and SAGA (had issues installing on OSX)?