ftle

Finite time Lyapunov exponent (FTLE) from analytical velocity field

• velocity field expression parsing (string in config file)

  • using the beautiful tool exprtk https://code.google.com/p/exprtk/

• the method is explained in multiple papers from G. Haller, F. Lekien. and S.C. Shadden.

  • http://en.wikipedia.org/wiki/Lyapunov_exponent
  • http://mmae.iit.edu/shadden/LCS-tutorial/FTLE-derivation.html

Usage:

1. make with the Makefile or with CLion or other IDE
2. ./main/ftle.bin config.txt (or other configs in /run/)
3. Output file (ftle.dat) will be created in running directory
4. Open in Tecplot to visualize FTLE field