fatal: division by zero attempted

teresevo1 · 06-13-2010, 02:18 PM

I am just trying to run the script xyz2ecfg given at
http://www.jrkermode.co.uk/XYZScripts

But I am getting the error "fatal: division by zero attempted", even though I typed in exactly "xyz2ecfg.awk movie.xyz"

Please help!
Thanks!!

fruttenboel · 06-13-2010, 04:05 PM

Quote:

Originally Posted by teresevo1

I am just trying to run the script xyz2ecfg given at
http://www.jrkermode.co.uk/XYZScripts

But I am getting the error "fatal: division by zero attempted", even though I typed in exactly "xyz2ecfg.awk movie.xyz"

Please help!
Thanks!!

Can you post the script, in a CODE block?

colucix · 06-13-2010, 04:46 PM

Usually awk shows the number of the line where the error occurred. Please show us the complete error message along with the relevant parts of the code. My suspect is that the file movie.xyz is not actually an Extended XYZ file.

teresevo1 · 06-14-2010, 08:36 AM

The division by zero error first occur at the line:

Code:

g[0,0] = ((r[1,1] * r[2,2]) -\
(r[1,2] * r[2,1]))/det;

Here is the code:

Code:

#!/bin/awk -f

function ceiling(x)
{
  return (x == int(x)) ? x : int(x)+1
}

BEGIN {
  command="basename " ARGV[1] " .xyz";
  command | getline cfgbase;
  frame=0;
  print "Counting frames..."
  command="grep -c Lattice " ARGV[1];
  command | getline nframes;
  print "Got " nframes " frames.";
  format=sprintf("%%0%dd",ceiling(log(nframes)/log(10.0)))
 
  mass["Si"] = 28.085500;
}

{
  if (nframes == 1) {
    cfgfile=cfgbase ".cfg";
  } else {
    cfgfile=cfgbase sprintf(format,frame) ".cfg";
  }

  natoms=$1;
  printf "Frame "frame": " natoms" atoms              \r";

  print "Number of particles = "natoms > cfgfile;

  getline comment;
  print "# "comment >> cfgfile;

  match(comment,/Lattice="([^"]*)/,a);
  lat=a[1];
  split(lat,lattice);
   

  for (x=0; x<3; x++)
    for (y=0; y<3; y++) {
      r[x,y]=lattice[x*3+y+1];
      print "H0("x+1","y+1") = "r[x,y] >> cfgfile;
    }

  det = r[0,0]*(r[1,1]*r[2,2] - r[2,1]*r[1,2]) \
    - r[1,0]*(r[0,1]*r[2,2] - r[2,1]*r[0,2]) \
  + r[2,0]*(r[0,1]*r[1,2] - r[1,1]*r[0,2]);

  g[0,0] = ((r[1,1] * r[2,2]) -\
	    (r[1,2] * r[2,1]))/det;
  g[1,0] = ((r[0,2] * r[2,1]) -\
	    (r[0,1] * r[2,2]))/det;
  g[2,0] = ((r[0,1] * r[1,2]) -\
	    (r[0,2] * r[1,1]))/det;
  g[0,1] = ((r[1,2] * r[2,0]) -\
	    (r[1,0] * r[2,2]))/det;
  g[1,1] = ((r[0,0] * r[2,2]) -\
	     (r[0,2] * r[2,0]))/det;
  g[2,1] = ((r[0,2] * r[1,0]) -\
	     (r[0,0] * r[1,2]))/det;
  g[0,2] = ((r[1,0] * r[2,1]) -\
	     (r[1,1] * r[2,0]))/det;
  g[1,2] = ((r[0,1] * r[2,0]) -\
	    (r[0,0] * r[2,1]))/det;
  g[2,2] = ((r[0,0] * r[1,1]) -\
	     (r[0,1] * r[1,0]))/det;

  print ".NO_VELOCITY." >> cfgfile;

  match(comment,/Properties=([a-zA-Z0-9._:]*)/,a);
  props=a[1];
  nfields = split(props,a,":");

  delete lines;
  p=0;
  for (i = 4; i <= nfields; i++) {
    if (i % 3 == 1) name=a[i];

    if (i % 3 == 0) {
      for (j=0; j<a[i]; j++) {
        lines[p]="auxiliary["p"] = "name;
	p=p+1;
      }
    }
  }

  print "entry_count = "p+3 >> cfgfile;

  for (i=0; i<p; i++)
    print lines[i] >> cfgfile

  for (i=0; i<natoms; i++) {
    getline;
    
    print $1 >> cfgfile;
    print mass[$1] >> cfgfile;

    s[0]=$2;
    s[1]=$3;
    s[2]=$4;

    t[0] = g[0,0]*s[0]+g[0,1]*s[1]+g[0,2]*s[2];
    t[1] = g[1,0]*s[0]+g[1,1]*s[1]+g[1,2]*s[2];
    t[2] = g[2,0]*s[0]+g[2,1]*s[1]+g[2,2]*s[2];

    printf "%16.8f%16.8f%16.8f",t[0],t[1],t[2] >> cfgfile;

    for (j=5;j<=NF;j++) printf "%16.8f",$j >> cfgfile;
    printf "\n" >> cfgfile;
  }     

  close(cfgfile);
  frame=frame+1;
}

END {
  print "Done "frame" frames.                  "
}

colucix · 06-14-2010, 09:21 AM

Quote:

Originally Posted by teresevo1

The division by zero error first occur at the line:

Code:

g[0,0] = ((r[1,1] * r[2,2]) -\
(r[1,2] * r[2,1]))/det;

This means that 'det' is 0, 'r' is not assigned or it's 0 (see line 47), the same for 'lattice' (see line 43) and for 'lat' (see lines 36-38). I stay of my idea that the input file is not really an Extended XYZ.

You can easily verify by the following commands:

Code:

file movie.xyz

and if it is an ASCII text file:

Code:

head movie.xyz

You should see the line starting with Lattice with all the key/value pairs of an Extended XYZ.

teresevo1 · 06-14-2010, 12:23 PM

I am very new to this. When I type in

Code:

file movie.xyz

I get movie.xyz: ASCII text.

How do I write an extended xyz file? I just do >> vi movie.xyz and copy and paste the data.

Thanks in advance.

teresevo1 · 06-14-2010, 02:19 PM

This is movie.xyz

Code:

8
Lattice="5.44 0.0 0.0 0.0 5.44 0.0 0.0 0.0 5.44" Properties=species:S:1:pos:R:3 Time=0.0
Si        0.00000000      0.00000000      0.00000000
Si        1.36000000      1.36000000      1.36000000
Si        2.72000000      2.72000000      0.00000000
Si        4.08000000      4.08000000      1.36000000
Si        2.72000000      0.00000000      2.72000000
Si        4.08000000      1.36000000      4.08000000
Si        0.00000000      2.72000000      2.72000000
Si        1.36000000      4.08000000      4.08000000

colucix · 06-14-2010, 04:58 PM

Quote:

Originally Posted by teresevo1

I am very new to this. When I type in

Code:

file movie.xyz

I get movie.xyz: ASCII text.

This confirms that your file movie.xyz is an ASCII text file, as it should be. A general advice: if you're new to the linux command line, always (and I mean always) check the manual page of every command you're suggested to type. Don't trust commands blindly, since everyone could make a typo or a mistake of some kind. It's better you're sure about what you're doing.

But maybe you already did. This is ol' pedantic uncle colucix speaking!

colucix · 06-14-2010, 05:06 PM

Quote:

Originally Posted by teresevo1

This is movie.xyz

Yes. It is an extended XYZ file. On the other hand it is the example from the developers site, isn't it? Just out of curiosity I tried the code you've posted on the example file and it works for me. Having GNU Awk 3.1.6, here.

At this point I can't explain the error anymore. I have some experience with awk, but I cannot see any mistake in the code.

grail · 06-14-2010, 06:58 PM

My suggestion would be to work from the "det" backwards. According to the code and the supplied example your "det" value should equal : (5.44)^3

So throw in a print statement just after "det" is set and see what value is stored?
If this is equal to zero then you need to check further up the chain.