Revert to quadratic interpolation when selecting initial step-size.
Merge branch 'master' of https://github.com/stan-dev/stan
Use std::fabs in BFGS just to be safe.
Merge branch 'master' of https://github.com/stan-dev/stan
rstan, updated to Eigen 3.1.3
rstan, change due to 30c7e04cd2973c409a4d187ee60f393b40adccdb
Merge branch 'master' of https://github.com/stan-dev/stan
More detailed output during BFGS.
Better output with BFGS.
added block, sub_col, sub_row, head, tail functions with tests and function sigs and doc
Improved BFGS output.
Merge branch 'master' of https://github.com/stan-dev/stan
Revert change which broke BFGS optimization.