ImageFileCollection¶
- class msumastro.image_collection.ImageFileCollection(location=None, keywords=None, info_file=None)[source]¶
Bases: object
Representation of a collection of image files.
The class offers a table summarizing values of keywords in the FITS headers of the files in the collection and offers convenient methods for iterating over the files in the collection. The generator methods use simple filtering syntax and can automate storage of any FITS files modified in the loop using the generator.
Parameters: location : str, optional
path to directory containing FITS files
keywords : list of str or ‘*’, optional
Keywords that should be used as column headings in the summary table. If the value is or includes ‘*’ then all keywords that appear in any of the FITS headers of the files in the collection become table columns.
info_file : str, optional
Path to file that contains a table of information about FITS files.
Raises: ValueError
Raised if keywords are set to a combination of ‘*’ and any other value.
Attributes
location str, Path name to directory containing FITS files keywords list of str, Keywords currently in the summary table. files list of str, Unfiltered list of FITS files in location. summary_info astropy.table.Table of values of FITS keywords for files in the collection. Attributes Summary
files list of str, Unfiltered list of FITS files in location. keywords list of str, Keywords currently in the summary table. location str, Path name to directory containing FITS files summary_info astropy.table.Table of values of FITS keywords for files in the collection. Methods Summary
data([do_not_scale_image_data]) Generator that yields each image in the collection. files_filtered(**kwd) Determine files whose keywords have listed values. hdus([do_not_scale_image_data]) Generator that yields each HDU in the collection. headers([do_not_scale_image_data]) Generator that yields each header in the collection. values(keyword[, unique]) List of values for a keyword. Attributes Documentation
- keywords[source]¶
list of str, Keywords currently in the summary table.
Setting the keywords causes the summary table to be regenerated unless the new keywords are a subset of the old.
- summary_info[source]¶
astropy.table.Table of values of FITS keywords for files in the collection.
Each keyword is a column heading. In addition, there is a column called ‘file’ that contains the name of the FITS file. The directory is not included as part of that name.
Methods Documentation
- data(do_not_scale_image_data=False, **kwd)[source]¶
Generator that yields each image in the collection.
If any of the parameters save_with_name, save_location or clobber evaluates to True the generator will write a copy of each FITS file it is iterating over. In other words, if save_with_name and/or save_location is a string with non-zero length, and/or clobber is True, a copy of each FITS file will be made.
Parameters: save_with_name : str
string added to end of file name (before extension) if FITS file should be saved after iteration. Unless save_location is set, files will be saved to location of the source files self.location
save_location : str
Directory in which to save FITS files; implies that FITS files will be saved. Note this provides an easy way to copy a directory of files–loop over the image with save_location set.
clobber : bool
If True, overwrite input FITS files.
do_not_scale_image_data : bool
If True, prevents fits from scaling images. Default is False.
return_fname : bool, default is False
If True, return the tuple (header, file_name) instead of just header.
kwd : dict
Any additional keywords are used to filter the items returned; see Examples for details.
Returns: numpy.ndarray
If return_fname is False, yield the next image in the collection
(numpy.ndarray, str)
If return_fname is True, yield a tuple of (image, file path) for next the item in the collection.
- files_filtered(**kwd)[source]¶
Determine files whose keywords have listed values.
**kwd is list of keywords and values the files must have.
- The value ‘*’ represents any value.
- A missing keyword is indicated by value ‘’
Example: >>> keys = [‘imagetyp’,’filter’] >>> collection = ImageFileCollection(‘test/data’, keywords=keys) >>> collection.files_filtered(imagetyp=’LIGHT’, filter=’R’) >>> collection.files_filtered(imagetyp=’*’, filter=’‘)
NOTE: Value comparison is case insensitive for strings.
- hdus(do_not_scale_image_data=False, **kwd)[source]¶
Generator that yields each HDU in the collection.
If any of the parameters save_with_name, save_location or clobber evaluates to True the generator will write a copy of each FITS file it is iterating over. In other words, if save_with_name and/or save_location is a string with non-zero length, and/or clobber is True, a copy of each FITS file will be made.
Parameters: save_with_name : str
string added to end of file name (before extension) if FITS file should be saved after iteration. Unless save_location is set, files will be saved to location of the source files self.location
save_location : str
Directory in which to save FITS files; implies that FITS files will be saved. Note this provides an easy way to copy a directory of files–loop over the HDU with save_location set.
clobber : bool
If True, overwrite input FITS files.
do_not_scale_image_data : bool
If True, prevents fits from scaling images. Default is False.
return_fname : bool, default is False
If True, return the tuple (header, file_name) instead of just header.
kwd : dict
Any additional keywords are used to filter the items returned; see Examples for details.
Returns: astropy.io.fits.HDU
If return_fname is False, yield the next HDU in the collection
(astropy.io.fits.HDU, str)
If return_fname is True, yield a tuple of (HDU, file path) for next the item in the collection.
- headers(do_not_scale_image_data=True, **kwd)[source]¶
Generator that yields each header in the collection.
If any of the parameters save_with_name, save_location or clobber evaluates to True the generator will write a copy of each FITS file it is iterating over. In other words, if save_with_name and/or save_location is a string with non-zero length, and/or clobber is True, a copy of each FITS file will be made.
Parameters: save_with_name : str
string added to end of file name (before extension) if FITS file should be saved after iteration. Unless save_location is set, files will be saved to location of the source files self.location
save_location : str
Directory in which to save FITS files; implies that FITS files will be saved. Note this provides an easy way to copy a directory of files–loop over the header with save_location set.
clobber : bool
If True, overwrite input FITS files.
do_not_scale_image_data : bool
If True, prevents fits from scaling images. Default is True.
return_fname : bool, default is False
If True, return the tuple (header, file_name) instead of just header.
kwd : dict
Any additional keywords are used to filter the items returned; see Examples for details.
Returns: astropy.io.fits.Header
If return_fname is False, yield the next header in the collection
(astropy.io.fits.Header, str)
If return_fname is True, yield a tuple of (header, file path) for next the item in the collection.