VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Tue Feb 28 2017 - 16:55:41 CST

Hi,
  The VMD text rendering code doesn't currently possess logic to deal with
various possible text formatting scenarios other than the simplest case of
writing out a linear string of characters. If you want to draw formatted
paragraphs of text or multi-line text labels, I would suggest doing that
by writing a more complex version of your existing "label_atom" routine
such that it parses the incoming string, and generates a separate VMD
"draw" command for each linear string, but computing its own Y-coordinate
from the current line. You could use the Tcl "split" command to break
the incoming text at each linefeed or CRLF pair to produce a list of
strings, and then do a Tcl foreach loop incrementing a current line count,
and multiplying that line count against a Y-coordinate vertical spacing
to get a new starting point for each drawn text label. This should be pretty
easy to write and would work with all existing and past versions of VMD.

Cheers,
  John Stone
  vmd_at_ks.uiuc.edu

On Mon, Feb 27, 2017 at 06:35:04PM +0200, Garold Murdachaew wrote:
> Dear VMD Community,
>
> I would like to place some user-defined labels near atomic positions.
> I am using these commands:
>
> proc label_atom {selection_string label_string} {
> set sel [atomselect top $selection_string]
> if {[$sel num] != 1} {
> error "label_atom: '$selection_string' must select 1 atom"
> }
> # get the coordinates of the atom
> lassign [$sel get {x y z}] coord
> # and draw the text
> draw color purple
> draw text $coord $label_string size 0.6 thickness 3
> }
>
> graphics top delete all
>
> set mylabel [format "%s \n %7.3f" C168 0.134]
> label_atom index=168 $mylabel
> set mylabel [format "%s \n %7.3f" C223 0.123]
> label_atom index=223 $mylabel
>
> However, I am finding that the newline character \n, which should work
> in tcl, has no effect. I have also tried vertical tab, \v, also to no
> effect.
>
> Is there a way to vertically space labels? I need to do this to make
> the figure legible.
>
> Doing this in a separate program by hand would be quite tedious (I
> need to do this for a few frames of a number of trajectories, about 20
> labels per frame), and prone to error. Thus I would like to automate
> this as much as possible.
>
> Thank you in advance for your suggestions,
> Garold 

-- 
NIH Center for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
http://www.ks.uiuc.edu/~johns/           Phone: 217-244-3349
http://www.ks.uiuc.edu/Research/vmd/