To investigate how a small error in 
or 
will affect the error
parameter e, the values of the curve at each of the 1000 times calculated
above was compared to the value calculated when either or
was varied by a small amount. The sum of the square of these differences, e,
was calculated and is shown plotted against the percentage variation in
either or in figure 7-16.
Thus the difference between the average value of e found from curve fitting,
85,
and the expected value of 60, due to the discrete
nature of the grid, corresponds
to an error in of about 0.3% or an error in of about 4%.
