Date: Sat Jan 07 2017 - 06:30:21 CST

Thanks dear Norman for your attention. I use following .TCl file for
convert vel.dcd to .dat file, but i get this error "Invalid command
name "1". Can you help me about it?

proc v_com_traj {filename {dt 1} {selection all} {first_frame 0}

{frame_step 1} {mol top} args} {

set outfile [open $filename w]

set convFact 2035.4

set sel [atomselect $mol $selection frame 0]

set num_frames [molinfo $mol get numframes]

for {set frame $first_frame} {$frame < $num_frames} {incr frame

$frame_step} {

$sel frame $frame

set vcom [vecscale $convFact [measure center $sel weight mass]]

puts $outfile "$frame\t $vcom"


close $outfile


All the best