def slotutcfix(images,update,outfile,ampperccd,ignorexp,droplimit,inter,plotdata,logfile,verbose,debug):
with logging(logfile,debug) as log:
# set up the variables
utc_list = []
# is the input file specified?
saltsafeio.filedefined('Input',images)
# if the input file is a list, does it exist?
if images[0] == '@':
saltsafeio.listexists('Input',images)
# parse list of input files and place them in order
infiles=saltsafeio.listparse('Raw image',images,'','','')
infiles.sort()
# check input files exist
saltsafeio.filesexist(infiles,'','r')
# check to see if the output file exists and if so, clobber it
if os.path.isfile(outfile):
try:
os.remove(outfile)
except:
raise SaltIOError('File ' + outfile + ' can not be removed')
# open the outfile
if outfile:
try:
fout=open(outfile,'w')
except:
raise SaltIOError('File ' + outfile + ' can not be opened')
# get time of first exposure and basic information about the observations
infile=infiles[0]
struct=saltsafeio.openfits(infile)
# check to make sure slotmode data
detmode=saltsafekey.get('DETMODE',struct[0], infile)
if detmode != 'Slot Mode':
raise SaltIOError('Data are not Slot Mode Observations')
# Check to see if SLOTUTCFIX has already been run
# and print a warning if they have
if saltsafekey.found('SLOTUTC', struct[0]):
message='Data have already been processed by SLOTUTCFIX'
log.warning(message)
# check to make sure that it is the right version of the software
scamver=saltsafekey.get('DETSWV', struct[0], infile)
try:
scamver=float(scamver.split('-')[-1])
if 4.42 <= scamver <= 5.00:
pass
else:
raise SaltError('cannot currently correct this version of the SCAM software.')
except:
raise SaltError('Not able to read software version')
# requested exposure time
req_texp=saltsafekey.get('EXPTIME',struct[0],infile)
# how many extensions?
nextend=saltsafekey.get('NEXTEND',struct[0],infile)
# how many amplifiers
amplifiers=saltsafekey.get('NCCDS',struct[0],infile)
amplifiers = int(ampperccd*float(amplifiers))
if ampperccd>0:
nframes = nextend/amplifiers
nstep=amplifiers
else:
nframes = nextend
nstep=1
# how many total frame and unique times
ntotal=nextend*len(infiles)
nunique=len(infiles)*nframes-ignorexp+1
# Create arrays necessary for analysis
id_arr=np.arange(nunique)
utc_arr=np.zeros(nunique,dtype=float)
# Read in each file and make a list of the UTC values
if verbose:
log.message('Reading in files to create list of UTC values.')
j=0
for n,infile in enumerate(infiles):
# Show progress
if verbose:
percent=100.*float(n)/float(len(infiles))
ctext='Percentage Complete: %.2f\r' % percent
sys.stdout.write(ctext)
sys.stdout.flush()
struct=saltsafeio.openfits(infile)
if not len(struct)-1==nextend:
raise SaltIOError(infile,' has a different number of extensions from the first file')
# Skip through the frames and read in the utc
istart=1
if infile==infiles[0]:
istart=ignorexp*amplifiers+1
for i in range(istart,len(struct), amplifiers):
try:
utc_list.append(saltsafekey.get('UTC-OBS', struct[i], infile))
utc_arr[j]=slottool.getobstime(struct[i], infile)
j += 1
except Exception, e:
raise SaltIOError('Unable to create array of UTC times. Please check the number of extensions in the files')
# close FITS file
saltsafeio.closefits(struct)
# set up the other important arrays
try:
diff_arr=utc_arr.copy()
diff_arr[1:]=diff_arr[1:]-utc_arr[:-1]
diff_arr[0]=-1
dsec_arr=utc_arr-utc_arr.astype(int)
except:
raise SaltIOError('Unable to create timing arrays')
# calculate the real exposure time
if verbose:
log.message('Calculating real exposure time.')
real_expt, med_expt, t_start, t_arr, ysum_arr=calculate_realexptime(id_arr, utc_arr, dsec_arr, diff_arr, req_texp, utc_list)
# plot the results
if plotdata:
if verbose:
log.message('Plotting data.')
plt.ion()
plt.plot(t_arr,ysum_arr,linewidth=0.5,linestyle='-',marker='',color='b')
plt.xlabel('Time (s)')
plt.ylabel('Fit')
# Calculate the corrrect values
if verbose:
log.message('Calculating correct values')
i_start = abs(utc_arr-t_start).argmin()
t_diff=utc_arr*0.0+real_expt
nd=utc_arr*0.0
ndrop=0
for i in range(len(utc_arr)):
if utc_arr[i] >= t_start:
t_new=t_start+real_expt*(i-i_start+ndrop)
t_diff[i]=utc_arr[i]-t_new
while (t_diff[i]>real_expt and nd[i] < droplimit):
nd[i]+= 1
t_new=t_start+real_expt*(i-i_start+ndrop+nd[i])
t_diff[i]=utc_arr[i]-t_new
if (nd[i]<droplimit):
ndrop += nd[i]
else:
t_new=t_start+real_expt*(i-i_start)
t_diff[i]=utc_arr[i]-t_new
while (t_diff[i]>real_expt and nd[i] < droplimit):
nd[i]+= 1
t_new=t_start+real_expt*(i-i_start-nd[i])
t_diff[i]=utc_arr[i]-t_new
# calculate the corrected timestamp by counting 6 record files forward and
# 8 recored + unrecorded files back--or just 8*t_exp forward.
# if the object is near the end of the run, then just replace it with
# the correct value assuming no dropped exposures.
# first make the array of new times
new_arr=utc_arr-t_diff
# Next loop through them to find the corrected time
corr_arr=utc_arr*0.0
for i in range(len(new_arr)):
if i+6 < len(new_arr)-1:
corr_arr[i]=new_arr[i+6]-8*real_expt
else:
corr_arr[i]=new_arr[i]-2*real_expt
t_diff=utc_arr-corr_arr
# write out the first results
msg="Dwell Time=%5.3f Requested Exposure Time=%5.3f Nobs = %i Dropped = %i" % (real_expt, req_texp, nunique, ndrop)
if verbose:
log.message(msg)
if outfile:
fout.write('#'+msg+'\n')
fout.write('#%23s %2s %12s %12s %10s %8s %4s \n' % ('File', 'N', 'UTC_old', 'UTC_new', 'UTC_new(s)', 'Diff', 'drop' ))
# Give the user a chance to update the value
if inter:
message='Update headers with a dwell time of %5.3f s [y/n]? ' % real_expt
update=saltsafeio.yn_ask(message)
if not update:
message='Set Dwell Time manually [y/n]? '
update=saltsafeio.yn_ask(message)
if update:
message='New Dwell Time: '
real_expt=saltsafeio.ask(message)
try:
real_expt=float(real_expt)
except Exception, e:
msg='Could not set user dwell time because %s' % e
raise SaltError(msg)
sys.stdout.flush()
struct=saltsafeio.openupdatefits(infile)
# Skip through the frames and read in the utc
istart=1
if infile==infiles[0]:
istart=ignorexp*amplifiers+1
for i in range(istart,len(struct), amplifiers):
for k in range(0,amplifiers):
if update:
struct[i+k]=updateheaders(struct[i+k],i+k, t_diff[j], real_expt, utc_list[j], infile)
if outfile:
utc_new=saltsafekey.get('UTC-OBS', struct[i+k], infile)
utc_new_sec=slottool.getobstime(struct[i], infile)
fout.write('%25s %2i %12s %12s %7.3f %5.4f %4i \n' % (infile, i, utc_list[j], utc_new, utc_new_sec, t_diff[j], nd[j] ))
j += 1
# Housekeeping key words
if update:
history = 'SALTUTCFIX -- '
history += 'images='+infile+' '
saltsafekey.housekeeping(struct[0],'SLOTUTC','UTC has been corrected',history,infile)
# update fits file
if update:
saltsafeio.updatefits(struct)
saltsafeio.closefits(struct)
# close outfile
# Skip through the frames and read in the utc
istart = 1
if infile == infiles[0]:
istart = ignorexp * amplifiers + 1
for i in range(istart, len(struct), amplifiers):
for k in range(0, amplifiers):
if update:
struct[i + k] = updateheaders(
struct[i + k], i + k, t_diff[j], real_expt,
utc_list[j], infile)
if outfile:
utc_new = saltsafekey.get('UTC-OBS', struct[i + k],
infile)
utc_new_sec = slottool.getobstime(struct[i], infile)
fout.write('%25s %2i %12s %12s %7.3f %5.4f %4i \n' %
(infile, i, utc_list[j], utc_new,
utc_new_sec, t_diff[j], nd[j]))
j += 1
# Housekeeping key words
if update:
history = 'SALTUTCFIX -- '
history += 'images=' + infile + ' '
saltsafekey.housekeeping(struct[0], 'SLOTUTC',
'UTC has been corrected', history,
infile)
# update fits file
if update:
def slotutcfix(images, update, outfile, ampperccd, ignorexp, droplimit, inter,
plotdata, logfile, verbose, debug):
with logging(logfile, debug) as log:
# set up the variables
utc_list = []
# is the input file specified?
saltsafeio.filedefined('Input', images)
# if the input file is a list, does it exist?
if images[0] == '@':
saltsafeio.listexists('Input', images)
# parse list of input files and place them in order
infiles = saltsafeio.listparse('Raw image', images, '', '', '')
infiles.sort()
# check input files exist
saltsafeio.filesexist(infiles, '', 'r')
# check to see if the output file exists and if so, clobber it
if os.path.isfile(outfile):
try:
os.remove(outfile)
except:
raise SaltIOError('File ' + outfile + ' can not be removed')
# open the outfile
if outfile:
try:
fout = open(outfile, 'w')
except:
raise SaltIOError('File ' + outfile + ' can not be opened')
# get time of first exposure and basic information about the observations
infile = infiles[0]
struct = saltsafeio.openfits(infile)
# check to make sure slotmode data
detmode = saltsafekey.get('DETMODE', struct[0], infile)
if detmode != 'Slot Mode':
raise SaltIOError('Data are not Slot Mode Observations')
# Check to see if SLOTUTCFIX has already been run
# and print a warning if they have
if saltsafekey.found('SLOTUTC', struct[0]):
message = 'Data have already been processed by SLOTUTCFIX'
log.warning(message)
# check to make sure that it is the right version of the software
scamver = saltsafekey.get('DETSWV', struct[0], infile)
try:
scamver = float(scamver.split('-')[-1])
if 4.42 <= scamver <= 5.00:
pass
else:
raise SaltError(
'cannot currently correct this version of the SCAM software.'
)
except:
raise SaltError('Not able to read software version')
# requested exposure time
req_texp = saltsafekey.get('EXPTIME', struct[0], infile)
# how many extensions?
nextend = saltsafekey.get('NEXTEND', struct[0], infile)
# how many amplifiers
amplifiers = saltsafekey.get('NCCDS', struct[0], infile)
amplifiers = int(ampperccd * float(amplifiers))
if ampperccd > 0:
nframes = nextend / amplifiers
nstep = amplifiers
else:
nframes = nextend
nstep = 1
# how many total frame and unique times
ntotal = nextend * len(infiles)
nunique = len(infiles) * nframes - ignorexp + 1
# Create arrays necessary for analysis
id_arr = np.arange(nunique)
utc_arr = np.zeros(nunique, dtype=float)
# Read in each file and make a list of the UTC values
if verbose:
log.message('Reading in files to create list of UTC values.')
j = 0
for n, infile in enumerate(infiles):
# Show progress
if verbose:
percent = 100. * float(n) / float(len(infiles))
ctext = 'Percentage Complete: %.2f\r' % percent
sys.stdout.write(ctext)
sys.stdout.flush()
struct = saltsafeio.openfits(infile)
if not len(struct) - 1 == nextend:
raise SaltIOError(
infile,
' has a different number of extensions from the first file'
)
# Skip through the frames and read in the utc
istart = 1
if infile == infiles[0]:
istart = ignorexp * amplifiers + 1
for i in range(istart, len(struct), amplifiers):
try:
utc_list.append(
saltsafekey.get('UTC-OBS', struct[i], infile))
utc_arr[j] = slottool.getobstime(struct[i], infile)
j += 1
except Exception, e:
raise SaltIOError(
'Unable to create array of UTC times. Please check the number of extensions in the files'
)
# close FITS file
saltsafeio.closefits(struct)
# set up the other important arrays
try:
diff_arr = utc_arr.copy()
diff_arr[1:] = diff_arr[1:] - utc_arr[:-1]
diff_arr[0] = -1
dsec_arr = utc_arr - utc_arr.astype(int)
except:
raise SaltIOError('Unable to create timing arrays')
# calculate the real exposure time
if verbose:
log.message('Calculating real exposure time.')
real_expt, med_expt, t_start, t_arr, ysum_arr = calculate_realexptime(
id_arr, utc_arr, dsec_arr, diff_arr, req_texp, utc_list)
# plot the results
if plotdata:
if verbose:
log.message('Plotting data.')
plt.ion()
plt.plot(t_arr,
ysum_arr,
linewidth=0.5,
linestyle='-',
marker='',
color='b')
plt.xlabel('Time (s)')
plt.ylabel('Fit')
# Calculate the corrrect values
if verbose:
log.message('Calculating correct values')
i_start = abs(utc_arr - t_start).argmin()
t_diff = utc_arr * 0.0 + real_expt
nd = utc_arr * 0.0
ndrop = 0
for i in range(len(utc_arr)):
if utc_arr[i] >= t_start:
t_new = t_start + real_expt * (i - i_start + ndrop)
t_diff[i] = utc_arr[i] - t_new
while (t_diff[i] > real_expt and nd[i] < droplimit):
nd[i] += 1
t_new = t_start + real_expt * (i - i_start + ndrop + nd[i])
t_diff[i] = utc_arr[i] - t_new
if (nd[i] < droplimit):
ndrop += nd[i]
else:
t_new = t_start + real_expt * (i - i_start)
t_diff[i] = utc_arr[i] - t_new
while (t_diff[i] > real_expt and nd[i] < droplimit):
nd[i] += 1
t_new = t_start + real_expt * (i - i_start - nd[i])
t_diff[i] = utc_arr[i] - t_new
# calculate the corrected timestamp by counting 6 record files forward and
# 8 recored + unrecorded files back--or just 8*t_exp forward.
# if the object is near the end of the run, then just replace it with
# the correct value assuming no dropped exposures.
# first make the array of new times
new_arr = utc_arr - t_diff
# Next loop through them to find the corrected time
corr_arr = utc_arr * 0.0
for i in range(len(new_arr)):
if i + 6 < len(new_arr) - 1:
corr_arr[i] = new_arr[i + 6] - 8 * real_expt
else:
corr_arr[i] = new_arr[i] - 2 * real_expt
t_diff = utc_arr - corr_arr
# write out the first results
msg = "Dwell Time=%5.3f Requested Exposure Time=%5.3f Nobs = %i Dropped = %i" % (
real_expt, req_texp, nunique, ndrop)
if verbose:
log.message(msg)
if outfile:
fout.write('#' + msg + '\n')
fout.write('#%23s %2s %12s %12s %10s %8s %4s \n' %
('File', 'N', 'UTC_old', 'UTC_new', 'UTC_new(s)',
'Diff', 'drop'))
# Give the user a chance to update the value
if inter:
message = 'Update headers with a dwell time of %5.3f s [y/n]? ' % real_expt
update = saltsafeio.yn_ask(message)
if not update:
message = 'Set Dwell Time manually [y/n]? '
update = saltsafeio.yn_ask(message)
if update:
message = 'New Dwell Time: '
real_expt = saltsafeio.ask(message)
try:
real_expt = float(real_expt)
except Exception, e:
msg = 'Could not set user dwell time because %s' % e
raise SaltError(msg)
def slotphot(images,outfile,srcfile,newfits=None,phottype='square',
subbacktype='median',sigback=3,mbin=7,sorder=3,niter=5,sigdet=5,
contpix=10,ampperccd=2,ignorexp=6,driftlimit=10.,finddrift=True,
outtype='ascii',reltime=True,clobber=True,logfile='salt.log',
verbose=True):
"""Perform photometry on listed SALT slotmode *images*."""
with logging(logfile,debug) as log:
# set up the variables
entries = []
vig_lo = {}
vig_hi = {}
amp = {}
x = {}
y = {}
x_o = {}
y_o = {}
r = {}
br1 = {}
br2 = {}
hour = 0
min = 0
sec = 0.
time0 = 0.
nframes = 0
bin=mbin
order=sorder
# is the input file specified?
saltsafeio.filedefined('Input',images)
# if the input file is a list, does it exist?
if images[0] == '@':
saltsafeio.listexists('Input',images)
# parse list of input files
infiles=saltsafeio.listparse('Raw image',images,'','','')
# check input files exist
saltsafeio.filesexist(infiles,'','r')
# is the output file specified?
saltsafeio.filedefined('Output',outfile)
# check output file does not exist, optionally remove it if it does exist
if os.path.exists(outfile) and clobber:
os.remove(outfile)
elif os.path.exists(outfile) and not clobber:
raise SaltIOError('File '+outfile+' already exists, use clobber=y')
# open output ascii file
if outtype=='ascii':
try:
lc = open(outfile,'a')
except:
raise SaltIOError('Cannot open ouput file '+outfile)
# is the extraction region defintion file specified?
saltsafeio.filedefined('Extraction region defintion',srcfile)
# check extraction region defintion file exists
srcfile = srcfile.strip()
saltsafeio.fileexists(srcfile)
# read extraction region defintion file
amp, x, y, x_o, y_o, r, br1, br2=slottool.readsrcfile(srcfile)
# set the writenewfits parameter
if not newfits or newfits=='none':
writenewfits=False
else:
writenewfits=newfits
# get time of first exposure and basic information about the observations
infile=infiles[0]
struct=saltsafeio.openfits(infile)
# identify instrument
instrume,keyprep,keygain,keybias,keyxtalk,keyslot=saltsafekey.instrumid(struct,infile)
# how many extensions?
nextend=saltsafekey.get('NEXTEND',struct[0],infile)
if nextend < amp['comparison']:
msg='Insufficient number of extensions in %s' % (infile)
raise SaltIOError(msg)
# how many amplifiers?
amplifiers=saltsafekey.get('NCCDS',struct[0],infile)
amplifiers = int(ampperccd*float(amplifiers))
if ampperccd>0:
nframes = int(nextend/amplifiers)
nstep=amplifiers
else:
nframes = nextend
nstep=1
ntotal=nframes*len(infiles)
# image size
naxis1=saltsafekey.get('NAXIS1',struct[amp['comparison']],infile)
naxis2=saltsafekey.get('NAXIS2',struct[amp['comparison']],infile)
# CCD binning
ccdsum=saltsafekey.get('CCDSUM',struct[0],infile)
binx=int(ccdsum.split(' ')[0])
biny=int(ccdsum.split(' ')[1])
# Identify the time of the observations
ext = 1
try:
time0=slottool.getobstime(struct[ext], infile+'['+str(ext)+']')
dateobs=saltsafekey.get('DATE-OBS',struct[ext],infile)
dateobs=dateobs.replace('-','/')
except:
raise SaltIOError('No time or obsdate in first image')
# If a total file is to be written out, create it and update it
if writenewfits:
if os.path.isfile(writenewfits):
if clobber:
saltsafeio.delete(writenewfits)
else:
raise SaltIOError('Newfits file exists, use clobber')
try:
hdu=pyfits.PrimaryHDU()
hdu.header=struct[0].header
hdu.header['NCCDS']=1
hdu.header['NSCIEXT']=ntotal-ignorexp
hdu.header['NEXTEND']=ntotal-ignorexp
hduList=pyfits.HDUList(hdu)
hduList.verify()
hduList.writeto(writenewfits)
except:
raise SaltIOError('Could not create newfits file, '+writenewfits)
# Close image file
saltsafeio.closefits(struct)
# Read newfits file back in for updating
if writenewfits:
try:
hduList=pyfits.open(writenewfits,mode='update')
except:
raise SaltIOError('Cannot open newfits file '+writenewfits+' for updating.')
# set up the arrays
j=0
time=np.zeros(ntotal ,dtype='float')-1.0
dx=np.zeros(ntotal ,dtype='float')
dy=np.zeros(ntotal ,dtype='float')
tflux=np.zeros(ntotal ,dtype='float')
terr =np.zeros(ntotal ,dtype='float')
cflux=np.zeros(ntotal ,dtype='float')
cerr =np.zeros(ntotal ,dtype='float')
ratio=np.zeros(ntotal ,dtype='float')
rerr =np.zeros(ntotal ,dtype='float')
tgt_x=np.zeros(ntotal ,dtype='float')
tgt_y=np.zeros(ntotal ,dtype='float')
cmp_x=np.zeros(ntotal ,dtype='float')
cmp_y=np.zeros(ntotal ,dtype='float')
p_one=100./ntotal # One percent
p_old=-1 # Previous completed percentage
p_new=0 # New completed percentage
p_n=1 # Counter number
for infile in infiles:
# Log
if verbose:
log.message('Starting photometry on file '+infile, with_stdout=False)
struct=pyfits.open(infile)
# Skip through the frames and process each frame individually
for i in range(nframes):
# Show progress
if verbose:
p_new=int(p_n*p_one)
p_n+=1
if p_new!=p_old:
ctext='Percentage Complete: %d\r' % p_new
sys.stdout.write(ctext)
sys.stdout.flush()
p_old=p_new
if not (infile==infiles[0] and i < ignorexp):
ext=amp['comparison']+i*nstep
try:
header=struct[ext].header
array=struct[ext].data
array=array*1.0
except:
msg='Unable to open extension %i in image %s' % (ext, infile)
raise SaltIOError(msg)
# starti the analysis of each frame
# get the time
time[j]=slottool.getobstime(struct[ext],infile+'['+str(ext)+']')
# gain and readout noise
try:
gain=float(header['GAIN'])
except:
gain=1
raise SaltIOError('Gain not specified in image header')
try:
rdnoise=float(header['RDNOISE'])
except:
rdnoise=0
raise SaltIOError('RDNOISE not specified in image header')
# background subtraction
if not subbacktype=='none':
try:
array=subbackground(array, sigback, bin, order, niter, subbacktype)
except SaltError:
log.warning('Image '+infile+' extention '+str(ext)+' is blank, skipping')
continue
# x-y fit to the comparison star and update the x,y values
if finddrift:
carray, fx,fy=slottool.finddrift(array, x['comparison'], y['comparison'], r['comparison'], naxis1, naxis2, sigdet, contpix, sigback, driftlimit, niter)
if fx > -1 and fy > -1:
if fx < naxis1 and fy < naxis2:
dx[j]=x['comparison']-fx
dy[j]=y['comparison']-fy
x['comparison']=fx
y['comparison']=fy
x['target']=x['target']-dx[j]
y['target']=y['target']-dy[j]
else:
dx[j]=0
dy[j]=0
x['comparison']=x_o['comparison']
y['comparison']=y_o['comparison']
x['target']=x_o['target']
y['target']=y_o['target']
else:
msg='No comparison object found in image file ' + infile+' on extension %i skipping.' % ext
log.warning(msg)
pass
# do photometry
try:
tflux[j],terr[j],cflux[j],cerr[j],ratio[j],rerr[j]=slottool.dophot(phottype, array, x, y, r, br1, br2, gain, rdnoise, naxis1, naxis2)
except SaltError, e:
msg='Could not do photometry on extension %i in image %s because %s skipping.' % (ext, infile, e)
log.warning(msg)
tgt_x[j]=x['target']
tgt_y[j]=y['target']
cmp_x[j]=x['comparison']
cmp_y[j]=y['comparison']
# record results
# TODO! This should be removed in favor of the write all to disk in the end
if outtype=='ascii':
slottool.writedataout(lc, j+1, time[j], x, y, tflux[j], terr[j], cflux[j],cerr[j],ratio[j],rerr[j],time0, reltime)
# write newfits file
if writenewfits:
# add original name and extension number to header
try:
hdue=pyfits.ImageHDU(array)
hdue.header=header
hdue.header.update('ONAME',infile,'Original image name')
hdue.header.update('OEXT',ext,'Original extension number')
hduList.append(hdue)
except:
log.warning('Could not update image in newfits '+infile+' '+str(ext))
# increment counter
j+=1
# close FITS file
saltsafeio.closefits(struct)
# close newfits file
if writenewfits:
try:
hduList.flush()
hduList.close()
except:
raise SaltIOError('Cannot close newfits file.')
# write to output
if outtype=='ascii':
# close output ascii file
try:
lc.close()
except:
raise SaltIOError('Cannot close ouput file ' + outfile)
elif outtype=='fits':
print 'writing fits'
try:
c1=pyfits.Column(name='index',format='D',array=np.arange(ntotal))
if reltime:
c2=pyfits.Column(name='time',format='D',array=time-time0)
else:
c2=pyfits.Column(name='time',format='D',array=time)
c3=pyfits.Column(name='tgt_x',format='D',array=tgt_x)
c4=pyfits.Column(name='tgt_y',format='D',array=tgt_y)
c5=pyfits.Column(name='tgt_flux',format='D',array=tflux)
c6=pyfits.Column(name='tgt_err',format='D',array=terr)
c7=pyfits.Column(name='cmp_x',format='D',array=cmp_x)
c8=pyfits.Column(name='cmp_y',format='D',array=cmp_y)
c9=pyfits.Column(name='cmp_flux',format='D',array=cflux)
c10=pyfits.Column(name='cmp_err',format='D',array=cerr)
c11=pyfits.Column(name='flux_ratio',format='D',array=ratio)
c12=pyfits.Column(name='flux_ratio_err',format='D',array=rerr)
tbhdu=pyfits.new_table([c1,c2,c3,c4,c5,c6,c7,c8,c9,c10,c11,c12])
# Add header information
tbhdu.header.update('RELTIME',str(reltime),'Time relative to first datapoint or absolute.')
tbhdu.writeto(outfile)
print 'fits written to ',outfile
except:
raise SaltIOError('Could not write to fits table.')