| AHELP for CIAO 4.4 | write_pha |
Context: crates |
Synopsis
Write a PHACrateDataset to a file.
Syntax
write_pha(phadataset, filename [, clobber=False])
Description
- phadataset - a PHA Crate Dataset
- filename - name of the file
- clobber - should an output file be over-written if it already exists (default is False)?
The write_pha command creates an output file for the input PHACrateDataset.
Metadata handling
As discussed in ahelp read_file, the Crate and Crate Dataset objects do not retain all the information from the input file, which means that care should be taken when using the output from write_pha() with CIAO tools.
Example
>>> pha = read_pha("pha.fits")
>>> cr = pha.get_crate("SPECTRUM")
>>> pi = get_colvals(cr, "PI")
>>> flag = (pi > 10) & (pi < 700)
>>> cd = CrateData()
>>> cd.name = "QUALITY"
>>> cd.values = 1 * flag
>>> add_col(cr, cd)
>>> write_pha(cds, "no_qual.fits", clobber=True)Here we add a QUALITY column to the SPECTRUM block; setting rows to 1 for those PI bins greater than 10 and less than 700, and write out the results to no_qual.fits.
Changes in CIAO 4.4
PHA Dataset
The value returned by read_pha and used by write_pha is a PHA Crate Dataset; in earleir versions it was a Crate.
Error handling
The write_pha routine now raises an error rather than returning an integer.
The clobber argument
A clobber parameter has been added - which defaults to False - to control whether existing files will be overwritten or not.
Bugs
See the bug pages on the CIAO website for an up-to-date listing of known bugs.
Refer to the CIAO bug pages for an up-to-date listing of known issues.

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