tree ff1256caf75f43159be3c44b31448b4404b446bd
parent 621b79b972ddf88a6ecc23788953c5151f00a5c5
author Sameer Agarwal <sameeragarwal@google.com> 1498709799 -0700
committer Sameer Agarwal <sameeragarwal@google.com> 1499294458 -0700

Get rid of redundant function evaluations in LineSearchMinimizer

1. Replace LineSearch::Summary::optimal_step_size with
   LineSearch:Summary::optimal_point which is a FunctionSample.
2. Add the actual vector position and vector gradient of the
   point in the FunctionSample
3. Use the above two to get rid of an extraneous function evalation
   in LineSearchMinimizer.

Runtime performance is almost 2x improved as a result.

Thanks to @svenpilz for reporting this.

https://github.com/ceres-solver/ceres-solver/issues/296

Change-Id: Iebf2db7acecb2c95c9b1683b73cdc5faab78b02e