Empirical irradiance from 51472 samples at (5.26,1.26,0.001):

	6.23 watts/sq.meter

Empirical position gradient from .1 meter displacement:

	X Gradient:	-1.19 watts/sq.meter/meter
	Y Gradient:	 2.49 watts/sq.meter/meter

Pinterp estimate of position gradient using .2 meter disp:

	X Gradient:	-1.43 watts/sq.meter/meter
	Y Gradient:	 1.43 watts/sq.meter/meter

Rtrace calculation of irradiance from 10000 samples:

	6.10 watts/sq.meter

Greg's estimate of position gradient:

	X Gradient:	-1.73 watts/sq.meter/meter
	Y Gradient:	 2.51 watts/sq.meter/meter
