| | 7 | |
| | 8 | I have finally finished substantial work on psphotStack to address two outstanding issues. The first concerns the throughput: the radial aperture photometry was taking an unexpectedly long time to run, especially on gpc1 stacks (more so than my tests predicted). After adding some optimizations in the code, I discovered that there was a kind of memory leak acting as the main culprit. The problem was in the glibc level: memory which was being allocated and freed by the IPP functions was not being released to the system by the low-level memory manager. We've seen this kind of problem in certain cases in the past. The solution was to rework the code to avoid a certain sequence of memory allocation. This brought the processing time for one pass of the radial apertures from taking 300-500 seconds to < 1second. |
| | 9 | |
| | 10 | I also addressed the problem whereby the radial moment used to determine the kron magnitudes was being measured in too small of a window for certain classes of galaxies. The algorithm was not going out far enough to encompass the galaxy fluxes. I added code to better identify the boundary where the galaxy surface brightness profile meets the sky level as a starting point, and this gave much better comparisons to sextractors' kron magnitudes. |
| | 11 | |
| | 12 | I spent some time updating pantasks to allow user-specified 'nice' levels for different jobs, and also to allow the server to have a user-defined port range, allowing us to run several pantasks on the same computer (to better manage computing resources). |
