procedure tsample (imageFile, zinit, zfinal, zstep, reg1, all, reg2, reg3, reg4, outFile)

string imageFile	{prompt="List of images to be sampled (no @ symbol)"}
int zinit		{prompt="CS100 z-value for first image"}
int zfinal		{prompt="CS100 z-value for final image"}
int zstep		{prompt="Increment of z between images"}
string reg1		{prompt="Image region 1 for sampling"}
bool all		{yes, prompt="Sample one region only?"}
string reg2		{prompt="Image region 2 for sampling"}
string reg3		{prompt="Image region 3 for sampling"}
string reg4		{prompt="Image region 4 for sampling"}
string outFile		{prompt="Name of output file"}
struct *flist		# list-directed structure to go thru imageFile


begin

	# Variable Declarations:
	struct image		# image currently being sampled
	int i			# image counter
	string imageRegion	# image region being sampled 
	string list1values	# contains list1 values for JOINLINES routine
	string noteline1
 	string noteline2
	string noteline3
	string noteline4
	int zcurrent 		# current z-value


	

	flist = imageFile	

	# putting the contents of the list contained in imageFile
	# to the list-directed structure *flist

	# Make sure the IMAGES package is loaded:
	if (! defpac ("images")) {
		print("IMAGES package not loaded")
		bye
	}


	# Make sure the PROTO package is loaded:
	if (! defpac ("proto")) {
		print("PROTO package not loaded")
		bye
	}




	# Looping to form temporary file of sky background samples:
	i=0
	zcurrent = zinit
	while ( fscan(flist, image) != EOF) {


		# Getting rid of the ".imh" extension if present:
		j = strlen(image)
		if (substr (image, j-3, j) == ".imh")
			image = substr (image, 1, j-4)


		i=i+1
		print (zcurrent, >> "num.out")
		print (image,"     ",zcurrent)



		# For Region 1:
		imageRegion=image//reg1
		imstat(images=imageRegion,fields="mean",format=no, >> "reg1.out")
		



		# For remaining regions (if requested):	
		if (all == no) {
		imageRegion=image//reg2
		imstat(images=imageRegion,fields="mean",format=no, >> "reg2.out")

		imageRegion=image//reg3
		imstat(images=imageRegion,fields="mean",format=no, >> "reg3.out")

		imageRegion=image//reg4
		imstat(images=imageRegion,fields="mean",format=no, >> "reg4.out")

		}


		zcurrent = zcurrent+zstep


	}








	# Joining lists together:

	# list1values = imageFile//", num.out, reg1.out"
	list1values = "num.out, reg1.out"
	# this is defined so that filename listed under imageFile can be used

	if (all == yes) {
		joinlines(list1=list1values,output=outFile,delim="   ")
		print ("# sliceNum  z-value  region1", >> outFile)
		print ("#   ", >> outFile)
		noteline1 = "#    Region 1 = "//reg1
		print (noteline1, >> outFile)
		# print (noteline5, >> outFile)


		

	}
		



	if (all == no) {
		joinlines(list1=list1values,output="lis1.out",delim="   ")
		joinlines(list1="lis1.out, reg2.out",output="lis2.out",delim="   ")
		joinlines(list1="lis2.out, reg3.out",output="lis3.out",delim="   ")
		joinlines(list1="lis3.out, reg4.out",output=outFile,delim="   ")
		print ("# sliceNum  z-value  region1   region2  region3  region4", >> outFile)
		print ("#   ", >> outFile)
		noteline1 = "#    Region 1 = "//reg1
		noteline2 = "#    Region 2 = "//reg2
		noteline3 = "#    Region 3 = "//reg3
		noteline4 = "#    Region 4 = "//reg4
		print (noteline1, >> outFile)
		print (noteline2, >> outFile)
		print (noteline3, >> outFile)
		print (noteline4, >> outFile)
		print ("#   ", >> outFile)
		# print (noteline5, >> outFile)






	}
		
		
	type (input_file=outFile)





	zcurrent = zcurrent-zstep		

	if (zcurrent==zfinal) {
		print("Final value of zcurrent agrees with zfinal...")
	} else {
		print("Final value of zcurrent DISAGREES with zfinal...")
		print(zcurrent)
		print(zfinal)
	}






	# Adding file headings (at end of file):



	# Deleting temporary files:
	delete(files="reg?.out",go_ahead=yes,verify=no)
	delete(files="lis?.out",go_ahead=yes,verify=no)
	delete(files="num.out",go_ahead=yes,verify=no)






end