#This task removes the Zero.
# task $y4kzero=/home/massey/survey/y4kzero.cl
delete("zeros")
hselect("Ty*.fits","$I","imgtype='BIAS'",>"zeros")
hselect("Ty*.fits","$I","imgtype='ZERO'",>>"zeros")
#
count("zeros") | scan (x)
if(x<3) {
!pwd
!pwd >> "../ERRORLOG"
print("No biases!")
print("No biases!",>>"../ERRORLOG")
}
else {
imdelete("Zero.fits")
#Make the bias frame
imcombine("@zeros","Zero.fits",combine="median",reject="none",scale="none")
delete("flatsobjs")
#Identify flats and objects
hselect("%T%%y*.fits","$I","imgtype='FLAT'",>"flatsobjs")
hselect("%T%%y*.fits","$I","imgtype='OBJECT'",>>"flatsobjs")
#Do the bias subtraction:
#First, get rid of the images if they already exist:
imdelete("Z//@flatsobjs")
imarith("T//@flatsobjs","-","Zero","Z//@flatsobjs",verbose+)
#Do a little cleaning:
delete("zeros")
delete("flatsobjs")
}