1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# Aaron LI
# 2015/06/16
#
# Changelogs:
# 0.2.0, 2015/06/16, Aaron LI
# * append the new time column to the *last*, rather than inserting
# to the beginning
# * explicitly update header from the new generated table
#
# BUGS:
# * comments of columns will lost after modified by astropy.io.fits,
# which is a bug with this package
#
"""
Add a time column for the chandra blanksky event file.
The time data are generated with a uniform distribution
between TSTART and TSTOP.
"""
__version__ = "0.2.0"
__date__ = "2015/06/16"
import sys
import argparse
import numpy as np
try:
from astropy.io import fits
except ImportError:
try:
import pyfits as fits
except ImportError:
raise ImportError("cannot import 'astropy.io.fits' or 'pyfits'")
def add_time_column(fitsfile, blockname="EVENTS"):
"""
Add a time column to the specified block of the input fits file.
The time data are generated with a uniform distribution
between TSTART and TSTOP.
Return:
A fits object with the new time column.
"""
if isinstance(fitsfile, str):
fitsfile = fits.open(fitsfile)
table = fitsfile[blockname]
tstart = table.header["TSTART"]
tstop = table.header["TSTOP"]
counts = len(table.data)
time_data = np.random.uniform(tstart, tstop, counts)
time_col = fits.Column(name="time", format="1D", unit="s", array=time_data)
# NOTE: append the new time column to the *last*!
# Otherwise the TLMIN??/TLMAX?? keyword pairs, which record the
# minimum/maximum values of corresponding columns, will become
# *out of order*. Therefore the output FITS file causes weird problems
# with DS9 and DM tools.
newtable = fits.BinTableHDU.from_columns(
table.columns + fits.ColDefs([time_col]))
fitsfile[blockname].data = newtable.data
# update header
fitsfile[blockname].header.update(newtable.header)
return fitsfile
def main():
parser = argparse.ArgumentParser(
description="Add a time column for Chandra blanksky event file.")
parser.add_argument("-V", "--version", action="version",
version="%(prog)s " + "%s (%s)" % (__version__, __date__))
parser.add_argument("infile", help="input chandra blanksky file")
parser.add_argument("outfile", nargs="?", default=None,
help="modified blanksky file. IN-PLACE modification if omitted.")
parser.add_argument("-C", "--clobber", dest="clobber",
action="store_true", help="overwrite output file if exists")
args = parser.parse_args()
newfits = add_time_column(args.infile)
if args.outfile:
newfits.writeto(args.outfile, clobber=args.clobber)
else:
newfits.writeto(args.infile, clobber=True)
if __name__ == "__main__":
main()
|
