Re: [Chimera-users] estimaded standard deviation (sigma levels) for electron densities in volume viewer

Hi Sabuj, When setting volume data threshold levels based on the appearance of the volume viewer histogram it is important to know that the heights of the histogram bars are the logarithm of the number grid points in the density range (bin) represented by that histogram bar. So if one histogram bin contains 10 volume grid points and another contains 1000, then the larger one will be 3 times higher than the smaller (not 100 times higher). So the bars for high density values appear much taller than if they directly represented the number of density values. It is done this way so useful information can be seen in the histogram outside of the noise density range. Tom