proc colordisplace {chain start end shift} {
puts "calculating displacements of atoms on residues for a given chain with shifted residues (opt)"
#
#  by Ch. Fufezan in 2006 - www.fufezan.net/sci_scripts.php
#
set selector "chain $chain"
set al1 [atomselect 0 "$selector"]
set al2 [atomselect 1 "$selector"]
#$al1 set beta 0

	for {set i $start} {$i <$end} {incr i} {
		set w 0
		set tmp "chain $chain and resid $i"
		set aa1 [atomselect 0 "$tmp"]
		##-> if wrongly numbered
		if {$shift != 0} {
			set numba [expr $i + $shift] 
			set tmp "chain $chain and resid $numba"
			}		
		##----------------------
		set aa2 [atomselect 1 "$tmp"]
			if {$i == $start} {
				set res1 [$aa1 get {resname resid}]
				set res2 [$aa2 get {resname resid}]
			    puts "Shift align puts $res1 with $res2"
			}
			if {[$aa1 num] - [$aa2 num] != 0} {
				set a0 [$aa1 num]
				set a1 [$aa2 num]
				puts "-> Resid $i 0:$a0 / 1:$a1"
			} else {
			set calf "alpha and (chain $chain and resid $i)"
			set calff [atomselect 0 "$calf"]
		foreach v0 [$aa1 get {x y z}] v1 [$aa2 get {x y z}] idx1 [$aa1 get {index}] {
		#graphics 0 color red
		#graphics 0 cylinder $v0 $v1 radius 0.2
		set dx [expr [lindex $v0 0] - [lindex $v1 0]]
		set dy [expr [lindex $v0 1] - [lindex $v1 1]]
		set dz [expr [lindex $v0 2] - [lindex $v1 2]]
   		set displace [expr (sqrt($dx*$dx + $dy*$dy + $dz*$dz))]
   		set enhanced [expr (10 * $displace)]
   		if {$enhanced >= $w} {
   							set w $enhanced
   							$calff set beta $w
   							}
		set aim "index $idx1"
		set target [atomselect 0 "$aim"]
		$target set beta $enhanced
		}
				}
	}
}