Data processing

Changing the comma as decimal seperator

Depending on the selected language of the operating system, behindLight seperates decimal places and integers with a comma. Sometimes it might be helpful to change these commas to dots. This can be obtained by the search and replace function of nearly any text editor or text processing software. One of the fastest ways is to use sed (project's homepage), particular useful for batch processing of multiple sic-files:

$> cat datafile.sic | sed -e s/,/\./g > newdatafile.sic

Converting sic to ras-format

behindLight stores data in the following order: x, y, z [,additional recorded value]. There is the ras-file format that uses y, x, z [,additional recorded value]. To convert files between these two formats you could use awk (gawk at gnu.org), also very useful for batch processing:

$> cat datafile.sic | awk '{ print $2" "$1" "$3" "$4 }' > datafile.ras 

Filtering the image

If you want the ground, the sample is attached to, to be flattened, one easy way is to substract a certain value from the z-data and set every value less than zero to zero. This simple command line php script sets everything containing a minus-sign to zero:

#!/usr/bin/php
<?php

$file   = $argv[1];
$outfile= $argv[2];

if ($argv[2] === null) $outfile=$file;

$lines = file($file);

$handle = fopen($outfile,"w");

foreach ($lines as $line){
  list($x,$y,$z) = split (" ",$line);
  if( strpos($z,"-") === false){
    fwrite($handle, $line);
  } else {
    fwrite($handle, $x." ".$y." 0\n");
  }
}
?>

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