> existing delta mask 0.3989 0.2420 0.0540 0.0044 0.0001
> alternative integral mask 0.4420 0.1331 0.0709 0.0448 0.0302
I agree with your remark: values should indeed be integrals of the Gauss
curve between x0.5 and x+0.5 (for x=0,1,2...)
But I don't agree with your numbers: I believe the correct values (for
sigma=1) should be: 0.38292 0.24173 0.06060 0.005977 0.000229
which are: $\int_{0.5}^{0.5} exp(x*x/2) dx$, $\int_{0.5}^{1.5} ...$
or: erf(0.5/sqrt(2)), 0.5*(erf(1.5/sqrt(2))erf(0.5/sqrt(2)), ...
I have now (for the time being) replaced the implementation by using a
16piece trapezoid appoximation of the integral between x0.5 and x+0.5.
The obtained values are very close to the ones above.
Peter.
