TTVFast efficiently calculates transit times for n-planet systems and the corresponding radial velocities.

The C version of the code is in the directory c_version, the Fortran version is in fortran_version. Both versions have specific README files.

There is a Julia interface in the directory jl_version. First, you must create libttvfast.so (e.g., "cd jl_version; source compile_libttvfast.cmd" on Linux). Once you've done this, start julia and type 'include("demo_julia.jl")' to see an example of calling ttvfast and accessing the outputs from Julia. There's another example of using the same input file foramts as TTVFast.

If you use this code, please cite Deck, Agol, Holman, & Nesvorny (2014), ApJ, 787, 132, arXiv:1403.1895.

Please check back for updates to ensure that you are using the latest version.

-Katherine Deck, Eric Agol, Matt Holman, & David Nesvorny