def nirc_sky(image, bpm):
usebpm = 0
if len(bpm) > 0:
re1 = re.search("^\!(\w+)", bpm)
if re1:
bpmkey = re1.group(1)
bpmfile = get_head(image, bpmkey)
else:
bpmfile = bpm
if len(bpmfile) > 0 and os.path.exists(bpmfile):
usebpm = 1
if usebpm:
mimstat = iraf.mimstatistics(
image,
imasks='!BPM',
omasks="",
fields='image,npix,mean,stddev,min,max,mode',
lower='INDEF',
upper='INDEF',
nclip=4,
lsigma=5.0,
usigma=5.0,
binwidth=0.1,
format=no,
Stdout=1,
Stderr=1)
mimels = mimstat[0].split()
skybkg = None
if len(mimels) == 6:
try:
skybkg = float(mimels[5])
except:
pass
if not skybkg:
usebpm = 0
if not usebpm:
iraf.iterstat(image, nsigrej=5, maxiter=10, prin=no, verbose=no)
skybkg = float(iraf.iterstat.median)
return skybkg
def wirc_sky(image,bpm):
usebpm=0
if len(bpm)>0:
re1=re.search("^\!(\w+)",bpm)
if re1:
bpmkey=re1.group(1)
bpmfile=get_head(image,bpmkey)
else:
bpmfile=bpm
if len(bpmfile)>0 and os.path.exists(bpmfile):
usebpm=1
if usebpm:
mimstat=iraf.mimstatistics(image,imasks='!BPM',omasks="",
fields='image,npix,mean,stddev,min,max,mode',
lower='INDEF',upper='INDEF',nclip=4,
lsigma=5.0,usigma=5.0,binwidth=0.1,
format=no,Stdout=1,Stderr=1)
mimels=mimstat[0].split()
skybkg=None
if len(mimels)==6:
try:
skybkg=float(mimels[5])
except:
pass
if not skybkg:
usebpm=0
if not usebpm:
iraf.iterstat(image,nsigrej=5,maxiter=10,
prin=no,verbose=no)
skybkg=float(iraf.iterstat.median)
return skybkg
def wirc_flatscale(infiles,inflat,outflat,clipfrac=0.03,
clobber=globclob):
# "infiles" is a list of filenames
inlist=','.join(infiles)
bpmfile=get_head(infiles[0],'BPM')
# Make a median combination of input files
imcmb1=iraf.mktemp("iqwircc")+".fits"
iraf.imcombine(inlist,imcmb1,combine="median",reject="none",
project=no,outtype="real",outlimits="",offsets="",
masktype="none",blank=0.0,scale="!SKYBKG",zero="none",
weight="none",statsec="",lthreshold="INDEF",
hthreshold="INDEF",nkeep=1)
[naxis1,naxis2]=get_head(imcmb1,['NAXIS1','NAXIS2'])
npixall=float(naxis1)*float(naxis2)
# Calculate sky background & divide, subtract 1
skybkg=wirc_sky(imcmb1,bpmfile)
imcmb2=iraf.mktemp("iqwircc")+".fits"
iraf.imarith(imcmb1,'/',skybkg,imcmb2,verbose=no,noact=no)
iraf.imdel(imcmb1,verify=no,go_ahead=yes)
iraf.imarith(imcmb2,'-',1.0,imcmb1,verbose=no,noact=no)
# Surface fit to median image
imsurf1=iraf.mktemp("iqwircs")+".fits"
iraf.imsurfit(imcmb1,imsurf1,xorder=6,yorder=6,type_output="fit",
function="chebyshev",cross_terms=yes,
xmedian=21,ymedian=21,median_percent=50.0,
lower=0.0,upper=0.0,ngrow=0,niter=0,
regions="all",rows="*",columns="*",border=50,
sections="",circle="",div_min="INDEF")
# Corresponding bad pixel mask
imbpm1=iraf.mktemp("iqwircb")+".pl"
iraf.imexpr("abs(x)>%.3f ? 0 : 1" % clipfrac,imbpm1,x=imsurf1)
# Subtract 1.0 from flatfield
imflat1=iraf.mktemp("iqwircf")+".fits"
iraf.imarith(inflat,'-',1.0,imflat1,verbose=no,noact=no)
# Surface fit to the flatfield
imsurf2=iraf.mktemp("iqwircs")+".fits"
iraf.imsurfit(imflat1,imsurf2,xorder=6,yorder=6,type_output="fit",
function="chebyshev",cross_terms=yes,
xmedian=21,ymedian=21,median_percent=50.0,
lower=0.0,upper=0.0,ngrow=0,niter=0,
regions="all",rows="*",columns="*",border=50,
sections="",circle="",div_min="INDEF")
# Corresponding bad pixel mask
imbpm2=iraf.mktemp("iqwircb")+".pl"
iraf.imexpr("abs(x)>%.3f ? 0 : 1" % clipfrac,imbpm2,x=imsurf2)
# Combine bad pixel masks for median + flat
imbpm3=iraf.mktemp("iqwircb")+".pl"
iraf.imexpr("(x>0 || y>0) ? 1 : 0",imbpm3,x=imbpm1,y=imbpm2)
# Calculate the ratio image
imratio=iraf.mktemp("iqwircr")+".fits"
iraf.imexpr("z>0 ? 0 : x/y",imratio,x=imsurf1,y=imsurf2,z=imbpm3)
# Mimstat on the ratio image
mimstat=iraf.mimstatistics(imratio,imasks=imbpm3,omasks="",
fields='image,npix,mean,stddev,min,max,mode',
lower='INDEF',upper='INDEF',nclip=4,
lsigma=5.0,usigma=5.0,binwidth=0.1,
format=no,Stdout=1,Stderr=1)
mimels=mimstat[0].split()
npix=float(mimels[1])
xmult=float(mimels[2])
# Check that a reasonable number of pixels have made the grade
check_exist(outflat,'w',clobber=clobber)
if npix<0.05*npixall:
print "Less than 5% of pixels passed the cut... preserving flatfield"
iraf.imcopy(inflat,outflat,verbose=no)
xmult=1.0
else:
# Create the final flatfield image
iraf.imexpr("x*%.3f + 1" % xmult,outflat,x=imflat1)
# Update header keywords
update_head(outflat,'RESCALE',1,"Flatfield has been rescaled")
update_head(outflat,'ORIGFLAT',inflat,
"Input flatfield name (before rescaling)")
update_head(outflat,'XMULT',xmult,
"Multiplied ORIGFLAT by this factor to rescale")
# Clean up
iraf.imdel(imcmb1,verify=no,go_ahead=yes)
iraf.imdel(imcmb2,verify=no,go_ahead=yes)
iraf.imdel(imsurf1,verify=no,go_ahead=yes)
iraf.imdel(imsurf2,verify=no,go_ahead=yes)
iraf.imdel(imbpm1,verify=no,go_ahead=yes)
iraf.imdel(imbpm2,verify=no,go_ahead=yes)
iraf.imdel(imbpm3,verify=no,go_ahead=yes)
iraf.imdel(imflat1,verify=no,go_ahead=yes)
iraf.imdel(imratio,verify=no,go_ahead=yes)
