mol load gro after_full.gro trr test.trr

# start the cache for a given molecule
proc start_sscache {{molid top}} {
    global sscache_data
    if {! [string compare $molid top]} {
	set molid [molinfo top]
    }
    global vmd_frame
    # set a trace to detect when an animation frame changes
    trace variable vmd_frame($molid) w sscache
    return
}

# remove the trace (need one stop for every start)
proc stop_sscache {{molid top}} {
    if {! [string compare $molid top]} {
	set molid [molinfo top]
    }
    global vmd_frame
    trace vdelete vmd_frame($molid) w sscache
    return
}


# reset the whole secondary structure data cache
proc reset_sscache {} {
    global sscache_data
    if [info exists sscache_data] {
        unset sscache_data
    }
    return
}

# when the frame changes, trace calls this function
proc sscache {name index op} {
    # name == vmd_frame
    # index == molecule id of the newly changed frame
    # op == w
   
    set fil [open he.dat a+] 
    global sscache_data

    
    # get the protein atoms
    set sel [atomselect $index "protein"]
    $sel frame $name
    
    
    ## get the new frame number
    # Tcl doesn't yet have it, but VMD does ...
    set frame [molinfo $index get frame]
    #set frame $name

    # see if the ss data exists in the cache
    if [info exists sscache_data($index,$frame)] {
	puts $fil nihao
	$sel set structure $sscache_data($index,$frame)
	return
    }
    puts $fil hello
    # doesn't exist, so (re)calculate it
    vmd_calculate_structure $index

    # save the data for next time
    set sscache_data($index,$frame) [$sel get structure]
    
    puts $fil $name\t$frame\n
    puts $fil $sscache_data($index,$frame)
    puts $fil "\n\n"
    close $fil
    return
}
	start_sscache
        set num_steps [molinfo top get numframes]
	
        for {set i 0} {$i < $num_steps} {incr i} {
	sscache $i 0 w
	reset_sscache
	}	
	stop_sscache