| 20 | 22 | * This was another week working on psphotStack. Progress was finally made on the memory usage problem. The primary issue is that in busy skycells (near the galacitc plane or containing a globular cluster) many large footprints that contain many sources are being created. In the merge process, where the "missing" sources found in one filter but not in another are prepared for forced photometry analysis, these footprints were being copied for each "missing" source. Since some of these were so large - as big as the input images - and complex - hundreds of thousands of spans, and contained tens of thousands of sources, these consumed all memory and swap space. Implemented a cache so only one copy is made for each input and this eliminatedd. However there are certain places in the code which handle these large footprints sub-optimally. For one skycell in the galactic plane it took about 18 hours to complete the analysis. But it did complete. |
