Using PyPlate¶
Working with metadata¶
An archive is a collection of photographic plates, logbooks, observer notes,
etc. In PyPlate, an archive is represented with the Archive class in
the metadata module. An individual plate is represented with the Plate
and a FITS header with PlateHeader class.
Initialise an archive:
import pyplate
archive = pyplate.metadata.Archive()
Optionally, specify a configuration file:
archive.assign_conf('/path/to/conf.cfg')
Importing metadata from files¶
Metadata can be conveniently imported from the Wide-Field Plate Database (WFPDB) files and comma-separated values (CSV) files.
Import metadata from WFPDB files:
archive.read_wfpdb(wfpdb_dir='/path/to/wfpdb_dir',
fn_maindata='maindata.txt', fn_quality='quality.txt',
fn_notes='notes.txt', fn_observer='observer.txt')
Import metadata from CSV files:
archive.read_csv(csv_dir='/path/to/csv_dir', fn_plate_csv='plates.csv',
fn_scan_csv='scans.csv', fn_logpage_csv='logpages.csv')
Creating and managing a FITS header¶
Create an empty header:
pheader = pyplate.metadata.PlateHeader()
pheader.populate()
Create header from a FITS file:
pheader = pyplate.metadata.PlateHeader.from_fits('/path/to/file.fits')
Create header from a text file that contains a FITS header:
pheader = pyplate.metadata.PlateHeader.from_hdrf('/path/to/file.hdrf')
Update header with metadata:
pmeta = pyplate.metadata.Plate()
pheader.update_from_platemeta(pmeta)
Configure input and output directories:
pheader.fits_dir = '/path/to/fits_dir'
pheader.write_fits_dir = '/path/to/write_fits_dir'
pheader.write_header_dir = '/path/to/write_header_dir'
Write header to a FITS file in write_fits_dir:
pheader.output_to_fits('file.fits')
If the FITS file exists, then its header is updated with pheader. If the
file does not exist, then PyPlate assumes that the file with the same name
exists in fits_dir. The file is then opened for reading and an output
file is written to write_fits_dir with the current header.
Write header to a text file in write_header_dir:
pheader.output_to_fits('file.hdr')
Extracting sources from a plate image and solving astrometry¶
Initialise plate process:
proc = pyplate.solve.SolveProcess('file.fits')
Configure process:
proc.fits_dir = '/path/to/fits_dir'
proc.tycho2_dir = '/path/to/tycho2_dir'
proc.work_dir = '/path/to/work_dir'
proc.write_source_dir = '/path/to/write_source_dir'
proc.write_wcs_dir = '/path/to/write_wcs_dir'
proc.write_log_dir = '/path/to/write_log_dir'
Alternatively, specify a configuration file or pass a variable containing configuration:
proc.assign_conf('/path/to/conf_file.cfg')
# Use Archive configuration instead
proc.assign_conf(archive.conf)
Set up process:
proc.setup()
Extract sources:
proc.extract_sources()
Finish process:
proc.finish()