Example data for using the DCSmooth functions. Data resembles two gaussian
peaks on the interval \([0,1] \times [0,1]\) with maxima
at \((0.5, 0.3)\) with variance matrix \(0.1 \cdot {\bf I}\)
and at \((0.2, 0.8)\) with variance matrix \(0.05 \cdot {\bf I}\), where \({\bf I}\) represents the \(2 \times 2\)
identity matrix.