Sept 1st, 2019 - Lenspix Inducing Negative Pixels?

When I took the log of the lensed CIB in the previous post, an error turned up telling me that some values were invalid. So I took a look at the histogram (below) and the lensed CIB certainly has some negative values (about 0.1% of all the pixels). It seems to me that the cut at 0 for the unlensed CIB is abrupt, and when Lenspix simulates the lensing, it tends to smooth out the histogram, without taking into account that some values are un-physical. I took a look at other lensed maps, including the null-lensed maps and they seem to have negative values as well. The question is, how much do these negative-value pixels affect our non-Gaussianity analysis? From a previous post, (https://mocks.cita.utoronto.ca/index.php/July_19th,_2019_-_Reduced_Bispectrum,_0th_Shell_Additional_Plots), I show that the interpolation effect by Lenspix (including the negative-value pixels) is tiny compared to the change in the bispectrum due to lensing. However, I have not calculated the interpolation effect after masking the brightest pixels (which are not affected by the lensing at all) although this probably will not cause a big difference. 

It seems that we (I) should take more care in validating our results when using 'lenspix' (being aware of what limits it has).