Visualizing code duplication as dot plots

 Lately I've been having to deal with some codebase which I suspected
  it had lots of duplicated code.

  My task was actually fix some parts of the application, cleanup the
  some of the parts, and end up owning the code as mine.

  So it was a perfect opportunity for me to give a serious thougth to 

Object Oriented Reengineering Patterns , refactoring, and Working with
  legacy code.  I started with OORP, because it's the less widely
  known about all three, and I thought maybe there would be advice
  that's not widely covered on other places in the internet.

  Among other advices (and related to other works in the smalltalk
  world), there's the thougth about trying to look at the code in
  different ways, not the obvious 'lines of text'.

  So here's dupplot, a small script I wrote to visualize code
  duplication through dotplots.

  While working with dupplot itself, I started pushing lines of code,
  to make it work the first time. And then, I was thinking that I had
  some code duplication (opening the file, normalizing lines,etc.) but
  it was generally ok-ish.

  Just for the sake of testing the program against itself, I ran it, and got this:

  So I thought that I'd try to fix some of the duplication, and yeah,
  now it looks much better.

Much much nicer, no? Both codes are available in https://github.com/kidd/dupplot, as dupplot.pl and dupplot2.pl.