I am trying to find clumps in a few wind-tunnel runs of a galaxy with ram pressure stripping, so that I can measure the mass, volume, etc.  I want to make sure, then, that I know how clump finder is selecting its contours.  Unfortunately, I am not getting the minimum densities that I am expecting--although not all the time!  

I have used IsolatedGalaxy and run the same clump finder routine, but with different maximum densities for the contours.  To reproduce my error I had to make the step size smaller--here I am using step = 1.1.  

Basically, I am not always stepping up my minimum density contour, even when the maximum density in the clump makes it clear I *should* be. 

I am attaching the script where I have cmax = 9.0e-24, which shows the error.  You can see that in the figure I attach, looking at the green triangles.  The y-axis is the maximum density in a clump, the x-axis is the minimum density.  To guide your eye I have drawn lines at each step.  Basically, no point should be above a black line and to the left of the connected vertical line (because then the max value is above the next possible minimum in the steps) *unless* the cmax value was reached.  To make this really clear if you look at the upper-left green triangle, the max density is ~7e-24 while the minimum density is ~3.6e-24--there are a lot of steps between those values--why is the minimum density not 6.68e-24?

Strangely enough, this problem does *not* show up when I have cmax = 6.7e-24 (cyan circles). 

I write out the max and min values in a text file at the end of the script, so I also attach the little script I use to make the figure.

Any help would be *much* appreciated!  

Thank you all,

Stephanie