I have data that is basically 3D (x,y, and temperature), a simple top view 3D plot in pgfplots
\documentclass{standalone}
\usepackage{tikz,pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[view={0}{90}]
\addplot3[surf] coordinates {
(-1.5,-1.5, 20) (-0.5,-1.5,21) (0.5,-1.5, 22) (1.5,-1.5,21)
(-1.5,-0.5, 21) (-0.5,-0.5,23) (0.5,-0.5, 22) (1.5,-0.5,20)
(-1.5,0.5, 22) (-0.5,0.5,23) (0.5,0.5, 24) (1.5,0.5,21)
(-1.5,1.5, 21) (-0.5,1.5,20) (0.5,1.5, 21) (1.5,1.5,22)
};
\end{axis}
\end{tikzpicture}
\end{document}
looks like this:
However, each of the points represents a 1x1 square, so the plot above should have 16 instead of 9 tiles, and span from (-2,-2) to (2,2).
How can I do that?

