roboptim/roboptim-core — pull request #12 by bchretien (2013-06-12 04:43:15+00:00)
Title: Add support for sparse Jacobian for Gnuplot display

Note that gnuplot apparently [does not support sparse matrix display](http://stackoverflow.com/questions/15655682/gnuplot-sparse-matrix-display), so a sparse to dense matrix conversion is involved.