procedure aba ( ipref, sp1, sp2, opref, so1 , flat, geom )

#
# Procedure to take ABA differences
# Richard Elston 5/8/93
#

string ipref    {prompt="input image prefix"}
int    sp1      {prompt="starting number of input image"}
int    sp2      {prompt="stopping number of input image"}
string opref    {prompt="output image prefix"}
int    so1      {prompt="starting output number"} 
string flat     {prompt="flat field frame"}
string geom     {prompt="Name of geomap image"}

begin
	int i
	string sa1, sa2, sb1, sb2, oname   
	string wrk1, wrk2
	string num1

	string inpref, outpref
	int p1, p2, o1

	inpref = ipref
	p1 = sp1
	p2 = sp2
	outpref = opref
	o1 = so1

	wrk1 = mktemp("xyz")
	wrk2 = mktemp("xyz")

	i=p1
	if ( i < 10 ) {
		sa1 = inpref//"00"//i
	}
	else if ( i < 100 ) {
		sa1 = inpref//"0"//i
	}
	else {
		sa1 = inpref//i
	}


	i = i+1
	if ( i < 10 ) {
		sb1 = inpref//"00"//i
	}
	else if ( i < 100 ) {
		sb1 = inpref//"0"//i
	}
	else {
		sb1 = inpref//i
	}


	if ( o1 < 10 ) {
		oname = outpref//"00"//o1
	}
	else if ( o1 < 100 ) {
		oname = outpref//"0"//o1
	}
	else {
		oname = outpref//o1
	}

	o1=o1+1
	imarith(sa1, "-", sb1, oname )
	imarith(oname, "/" , flat, oname)
	hedit(oname, "dispaxis", "2", add+, ver-)
	transform(oname, oname, geom)
	background(oname, wrk1, axis=1)
	imdel(oname)
	imrename(wrk1, oname)
#	display(oname, 1)
	
	p1=p1+2		


for ( i = p1 ; i <= p2 ; i += 1) {

	if ( i < 10 ) {
		sa2 = inpref//"00"//i
	}
	else if ( i < 100 ) {
		sa2 = inpref//"0"//i
	}
	else {
		sa2 = inpref//i
	}

	
	if ( o1 < 10 ) {
		oname = outpref//"00"//o1
	}
	else if ( o1 < 100 ) {
		oname = outpref//"0"//o1
	}
	else {
		oname = outpref//o1
	}

	o1=o1+1
	imarith(sa1, "+", sa2, wrk1)
	imarith(wrk1, '/', 2 , wrk1)
	imarith(sb1, "-" , wrk1 , oname)
	imarith(oname, "/" , flat, oname)
	hedit(oname, "dispaxis", "2", add+, ver-)
	transform(oname, oname, geom)
	background(oname, wrk2, axis=1)
	imdel(oname)
	imrename(wrk2, oname)
#	display(oname, 1)

	imdel(wrk1,ver-)
	imdel(wrk2,ver-)

	sa1=sb1
	sb1=sa2

}

	if ( o1 < 10 ) {
		oname = outpref//"00"//o1
	}
	else if ( o1 < 100 ) {
		oname = outpref//"0"//o1
	}
	else {
		oname = outpref//o1
	}

	o1=o1+1
	imarith(sb1, "-", sa1, oname )
	imarith(oname, "/" , flat, oname)
	hedit(oname, "dispaxis", "2", add+, ver-)
	transform(oname, oname, geom)
	background(oname, wrk1, axis=1)
	imdel(oname)
	imrename(wrk1, oname)
#	display(oname, 1)


	end