Deceptive Detection Policy Frontier Finder: User's Guide




Batik SVG Toolkit

The Deceptive Detection Policy Frontier Finder uses the Batik SVG Toolkit to produce image files, or to convert image files from SVG format to JPG or PNG formats. It is a free Apache product.

To make sending the distribution file by email, as well as later updating, easier, I don't include the Batik kit into it. Instead, please download the file from the download page.

You then need to extract the files from that archive to some directory on your computer; on a Linux host, it can be done with

     cd some_directory
This will have the subdirectoy "some_directory/batik-1.7" under the directory where you have started.

There are various ZIP tools installed on most MS Windows machine as well.

Installing from a ZIP file

If you have access to Sakai, and don't plan to do development work, it may be easiest from you to install the application from the ZIP file distributed at Sakai.

  1. Choose what directory you plan to install the Frontier Finder and the necessary libraries in. For the rest of the discussion, we'll assume that the directory (the "main directory") is called "dndo":
           mkdir dndo
  2. Install Batik. As per instructions in seciton 1, download the Batik zip file and unpack it, so that batik-1.7 will be a subdirectory of your main directory:
         cd dndo
  3. Download the distribution file for the current version of the Frontier Finder (e.g. from Sakai, and extract it into the main directory:
          cd dndo
    This way, your main directory will have a subdirectory for Batik and a subdirectory for Snsrtree, e.g.
    It does not have to be done in this way, but if you install DD and Batik in under different directories, you'd have to modify the classpath settings when runing our DD application.
  4. You don't need to recompile the Java program, since the code has been already compiled, and a Jar file is included in the distribution. Should you modify code in some way and need to recompile, you can do it by runing
    	   ant compile
    in the directory "snsrtree"

Installing from Google Code

An alternative process for installing the application is by downloading its source code from the repository at, and then recompiling it yourself.

Assuming that your "main" directory is called "dndo", you can check out the code from the repository as follows:

    cd dndo
    svn checkout snsrtree-read-only

You will also need to download the Batik toolkit (see above), and unpack it into a subdirectory of your main directory:

    cd dndo

Finally, you will also need to download two jar files from Apache web site (commons-fileupload-1.2.1.jar from , and commons-io-1.4.jar from ) and to install these jar files into snsrtree/lib :

    cd dndo
    cd snsrtree
    mkdir lib
(The Apache site may distribute Jar files not individually, but packaged with other files into ZIP of TAR.GZ files; you'd need to unpack those, and place the extracted jar files into snsrtree/lib).

Once everything is installed, you can run

    ant compile
in the snsrtree directory.

Running the GUI program

In UNIX, run this script in the directory "snsrtree":

In MS Windows, run "run.bat".

If the program fails during file-writing stage because it cannot find the Batik classes, it means that relative location of the batik-1.7 directory and the dd directory is not what it was expected to be. Move one of the directories, or modify in accordance with their actual location.

Reading the sensor list

Use the "File | Read Config File" menu item to read a config file in the same format as used by your old application. This config file is simply the list of sensor files, one file name per line. Each sensor file described a single sensor, in the format specified by Paul and used by your old application


Use the "Run | Compute frontier" menu item to compute the efficient frontier for the currently loaded set of sensors. It will take some time; you can watch the standard output (command line window) for the progress. Once the frontier has been computed, it will be plotted on the screen in the (Cost, DetectionRate) coordinates. The cost for each policy includes the stochastic cost of all tests and final inspections involved.

Saving as text

You can save results as text using the "File | Save frontier" menu

Saving as an image file

You can save results as an image file (SVG, JPG, or PNG) using the "File | Write frontier" menu. The output file format will be determined by the extension of the file name you have specified (.svg, .jpg, or .png).

What format to use? SVG is the recommended format, as it's a vector format (i.e., perfectly scalable and lossless). An SVG image can always be converted to JPG or PNG later on, with Batik utilities (and probably to PostScript too); it can be viewed in good web browsers, such as Firefox. Nonetheless, you can also save a graph directly as an image in PNG or JPG format, if this makes your life easier.

Saving approximated sensors

Since ver 1.6.2, eps is applied to original sensors, replacing them with "approximated" sensors, by merging some "thin" channels ("thinner" than eps in both C and D dimensions) into wider ones.

The description of the approximated sensors can be saved using the "File | Save sensors" menu item. You will then will need to pick an existing or new directory into which the data files will be saved. For each sensor, two files will be saves:

Viewing policies

Once a frontier has been computed and displayed on the screen, you can click a mouse button on any of the red circles representing policies. A menu will pop up, displaying basic info about the policy, and giving you an entry for plotting the decision tree of the policy. If you choose that entry, the decision tree for the chosen policy will be plotted in a separate new window.

Running the command-line program

You can also run the frontier computation without the GUI, purely as a batch job. E.g.
./ config.txt
time java -classpath classes dd.engine.Main config.txt
(The "time" command preceding the "java" program name, and also included in, provides for some runtime statistics from the UNIX shell - the user and system time, as well as wall-clock time, for the run)

Converting SVG files to JPG or PNG

If you are producing image files for importing into a document preparation system with PostScript or PDF output, such as LaTeX, SVG format is probably more suitable than JPG or PNG, because SVG is a vector format (and not a raster, i.e. bitmap, format as the other two), and SVG images can be scaled perfectly, without aliasing problems or quality loss. SVG files can also be viewed directly in many web browsers, such as modern versions of Firefox, or uploaded to image archive sites such as Wikipedia / Wikimedia Commons.

Nonetheless, you may need to convert an SVG file to JPG or PNG. The Batik SVG toolkit, which you have installed already, includes a tool for this. It can be used as follows.

To convert test.svg to test.png:

      java -jar ../batik-1.7/batik-rasterizer.jar test.svg 
To convert test.svg to test.jpg, using default quality:
      java -jar ../batik-1.7/batik-rasterizer.jar -m image/jpeg test.svg 
Same, with 80% quality:
      java -jar ../batik-1.7/batik-rasterizer.jar -m image/jpeg -q 0.8 test.svg 

More details on conversion (including dealing with multiple files at once) can be found here:

There is also script "" in the directory dd that you can use:

./ test.svg test.jpg