Command-Line Program ==================== .. _quickspecsim: QuickSpecSim ------------ This package includes a command-line program ``quickspecsim`` that simulates a single spectrum and saves the results as a FITS file and/or plot. To see the available command-line options use:: quickspecsim --help The ``--config`` parameter specifies the top-level :doc:`configuration file ` to use and defaults to ``test``. Without any arguments, the program simulates a constant flux density source using the test atmosphere and instrument models, producing the output:: Median SNR in b camera = 1.165 / 0.5 Angstrom Median SNR in r camera = 0.941 / 0.5 Angstrom Median SNR in z camera = 0.742 / 0.5 Angstrom Use the ``--output`` option to save the simulation results to a FITS file with the following structure (as reported by `fitsinfo `__):: No. Name Type Cards Dimensions Format 0 PRIMARY PrimaryHDU 5 () 1 SIMULATED BinTableHDU 45 63001R x 18C [D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D, D] 2 B BinTableHDU 29 4760R x 10C [D, D, D, D, D, D, D, D, D, D] 3 R BinTableHDU 29 4232R x 10C [D, D, D, D, D, D, D, D, D, D] 4 Z BinTableHDU 29 4798R x 10C [D, D, D, D, D, D, D, D, D, D] Use the ``-save-plot`` option to visualize the simulation results, for example:: quickspecsim -c desi --save-plot sim.png produces the following plot of a simulated 22nd AB magnitude reference source: .. image:: _static/desi_ab22.png :alt: Simulated DESI response A limited number of simulation parameters can be changed from the command line, such as the exposure time, airmass and source magnitude. For more substantial changes to the simulation models, copy and edit an existing configuration file. .. _quickfiberloss: QuickFiberLoss -------------- The ``quickfiberloss`` command-line program is primarily for performing speed benchmarks of fiber acceptance fraction calculations using GalSim, which are usually the rate-limiting step when these calculations are performed on the fly. To see the available command-line options use:: quickfiberloss --help The ``--config`` option has the same meaning as above, but only the ``instrument`` section of the configuration data will be used. Normal usage is, for example:: quickfiberloss -n 100 --disk-fraction 0.5 --bulge-fraction 0.5 Elapsed for 100 targets = 58.286 s, Rate = 582.861 ms/target To measure the speed up for disk-only galaxies, try:: quickfiberloss -n 100 --disk-fraction 1.0 --bulge-fraction 0.0 Elapsed for 100 targets = 1.708 s, Rate = 17.084 ms/target