Indeed, I've started with nice images on web which were described as "kriging", then went on to page about kriging, seen some general ideas and implemented what

Indeed, I've started with nice images on web which were described as "kriging", then went on to page about kriging, seen some general ideas and implemented what I thought would be fast, simple and work. That way I had something which looked right for my application (visualising district heating temperatures in city), but only now I know how it's really called. Still better looking that heatmap.