Urgent help needed about adding new operations using matlab

[Chi Ding <chi@xxxxxxxxx>]

Hi Jonathan
       I've spent several days on this problem and am still stuck there.
       What I want to do is to use a matlab routine to make plot, and 
then return the picture. My approach is like this. I added the operation 
in las.xml file and  a corresponding function in my custom/custom.pl. In 
the function, I forked a child process which execs a perl program with 
the output file name from LAS as parameter. Then the child process will 
create a LAS CLC session for matlab and create the picture I need. In 
the meantime the parent process will wait for it to die,then return. 
After that LAS will return the picture and the html file to the user. 
The code is  below.

  sub MooringPlotMatrix { # this is the new operation I add in 
custom/custom.pl file
      my $self = shift;

      my $output_file=$self->{output_file};
      my $program_pid = fork;
      if ($program_pid == 0)  {
             my $mycmd="/home/local/las/server/test.pl ".$output_file;
             exec($mycmd);
             exit(0);
     }
      # Here should be some statements the parent process waits for the 
child to die.
      # I haven't written the statements yet.
 }
  What I want to do is to call  "/home/local/las/server/test.pl " to 
create a picture file with the same name as the output file.  The file 
"/home/local/las/server/test.pl " basically just creates a CLC object of 
a matlab
session, and creates a file upon the input parameter, i.e., the file name.
   I'm attaching the test.pl and the corresponding matlab code here.
   The problem is that $output_file seems not passed into test.pl. No 
picture was created under server/output
as supposed.If I fix the filename in function sub MooringPlotMatrix like 
below
   my $mycmd="/home/local/las/server/test.pl  plot1", then it's fine, I 
can see plot1.png file is created
successfully under server/output.
   Other than this, I used to create a CLC session of matlab directly in  
    sub MooringPlotMatrix (the new operation I add) without forking a 
child process to create CLC, but it didn't generate the picture. I guess 
it might be relevant with the fact that it creates a child process for 
matlab, and it already created a child process for ferret, in sub 
preExecute( ), therefore it gets messy.
    I did all the tests using netscape 7.0 on a RedHat Linux 7.3. 
Matlab version is 6.5.
    Could anybody give me suggestions how to combine matlab and LAS? 
You information will be highly appreciated.
    Cheers, Ding

  

      
#!/usr/bin/perl 
use English;

use lib '.';
use CLC;

use Config;
use lib ('/home/local/las/xml/perl','/home/local/las', '/home/local/las/xml/perl/install/lib/' . $Config{version},
         '/home/local/las/xml/perl/install/lib/site_perl/' . $Config{version},
         '/home/local/las/xml/perl/install/lib/perl5/' . $Config{version},
         '/home/local/las/xml/perl/install/lib/perl5/site_perl/' . $Config{version});
use CGI qw(:standard); # Include standard HTML and CGI functions
use CGI::Carp qw(fatalsToBrowser); # Send error messages to browser
use LAS;
use LAS::Server;
#

# Use unbuffered output.
# Open a file for debugging output.
# Redirect stderr to stdout so we can see err msgs on the web.

$target_file=shift;

$OUTPUT_AUTOFLUSH = 1;
$debug_file="clc.debug";
#open(DBGFILE, ">$debug_file") || 
  #&mydie("Can't open $debug_file\n<P>\nAre the permissions set properly?");
#open (STDERR, ">&STDOUT") || &mydie("Can't dup stdout ($OS_ERROR)\n");
open(DBGFILE, ">$debug_file");
open (STDERR, ">&STDOUT");
print DBGFILE "\n";




	$matlab= new CLC("/home/local/las/server/matlab.sh", ">> ", \*DBGFILE);

$matlab->start("");
$matlab->wait_for_prompt;

$matlab->send_command("addpath /home/users/chi/public_html/las_mooring/");
$matlab->wait_for_prompt;

$matlab->send_command("myplot(\'$target_file\')");
$matlab->wait_for_prompt;

$matlab->send_command("quit");
$matlab->error_check("error on quit");

$matlab->close;

function myplot(filename) 
mb1=netcdf('/usr/local/ferret/go/mb1.nc');
air_temp=mb1{'Air_Temperature'}(:);
wind_speed=mb1{'Wind_Speed'}(:);
wind_direction=mb1{'Wind_Direction'}(:);
x=[ air_temp,wind_speed,wind_direction];
x(find(x==-99999))=nan;
plotmatrix(x);
eval(['print -dpng /home/local/las/server/output/' filename])