| | 3 | The detrend calculation was impractically slow in the previous version of prepare_chip. Since each imfile needs to have ~6-7 detrends identified, doing this with detselect commands was very slow. This led to an execution time for SAS of ~9 hours. The fix chosen was to have the script look up the information for all possible detrends, and compile this into an in-memory catalog. This makes the script start up much slower, but reduces the overall time for large datasets. A quick check comparing the old and new command lists shows that the two methods produce identical results. The speed of the new code is still long (~2 hours), but is definitely an improvement. For 620 exposures with 60 imfiles, this seems to work out to an average execution time of ~0.2s/imfile. |
