gaussian coefficients

[anArkitek]

Thank you for your well-commented program. I learned a lot from them.
I have a question about a line of code. In ezsift.cpp, line 218
gaussian_coefs[i][j] = expf(tmp * tmp * -0.5f) * (1 + j / 1000.0f);
I notice you have multiplied the exponential with a factor (1 + j / 1000.0f). Why would we need that, it seems will cause the gaussian kernel asymmetric any more?