#!/bin/csh -f
#+
# by3 -- acquire images in 3-pos pattern in DETECTOR coords w/ random dither
#
# Purpose:
#	Acquire a sequence of images using 3-positions in y
#	plus an optional random offset.
#
# Usage:
#	by3 dy [dx]
# 
# Arguments:
#	dy = size of the step in the "y" direction [arcsec]
#	dx = size of the random dither in x [arcsec, default=0]
# 
# Output:
# 
# Restrictions:
# 
# Exit values:
#	0 = normal completion
#	1 = wrong number of arguments
#	2 = arguments are not valid numbers
#
# Example:
#	1) Acquire 3 images using 1-arcsec steps in y:
#		by3 1
#	   Images are acquired at: (0.00,0.00), (0.00,1.00), (0.00,-1.00)
# 
# 	2) Acquire 3 images using 10-arcsec steps in y:
#		by3 10
#	   Images are acquired at: (0.00,0.00), (0.00,10.00), (0.00,-10.00)
#
# 	2) Acquire 3 images using 10-arcsec steps in y with 
#	   random 5 arcsec dither:
#		by3 10 5
#	   Images are acquired at: (-1.58,0.00), (-2.54,10.00), (2.76,-10.00)
#
#-
# Modification history:
#	2003-Apr-28	GDW	Original version
#-----------------------------------------------------------------------

set buf = $0
set cmd = $buf:t
set usage = "Usage: $cmd dy [dx]"
set dx = 0
set debug = 0
set foo = ""

# define the array of offsets...
set yoff = ( 0 1 -1)

# parse flags...
while ( $#argv > 0 )

    # check for debug...
    if ( "$1" == "-debug" ) then
	set debug = 1
	shift
	printf "DEBUG MODE ENABLED\n"
	set foo = "echo"		# set to "echo" for testing purposes
	continue
    endif

    # no flags found; so quit processing flags...
    break
end

# verify args...
if ( $#argv < 1 || $#argv > 2 ) then
  printf "$usage\n"
  exit 1
endif

# grab arguments...
if ( $#argv >= 1 ) then
    set dy = $1
    shift
endif
if ( $#argv >= 1 ) then
    set dx = $1
    shift
endif

# verify float-ation...
is_float $dx > /dev/null
if ( $status ) then
  echo "ERROR -- dx must be a valid number"
  exit 2
endif

is_float $dy > /dev/null
if ( $status ) then
  echo "ERROR -- dy must be a valid number"
  exit 2
endif

# save starting location...
$foo markbase
onintr last

@ i = 1
@ n = $#yoff
while ( $i <= $n )

    # generate random number...
    set r = `rand`
    set xx = `calc "$dx*(2.*($r-0.5))"`

    # compute new position...
    set yy = `calc "$dy*$yoff[$i]"`

    # move to appropriate location in absolute coordinate system...
    $foo mxy -abs $xx $yy

    # print message...
    printf "----------------------------------------\n"
    printf "Position $i at (%.2f,%.2f)\n" $xx $yy
    printf "----------------------------------------\n"

    # take image...
    $foo goi

    # increment...
    @ i++
end

last:
$foo gotobase
printf "Done.\n"
$foo bells 3