tree d4ad16e682119cca2f85f15496600a862a4b5008
parent 3e2cdca542cab14697a0d7e411d6243f73e40d71
author Sameer Agarwal <sameeragarwal@google.com> 1559253280 -0700
committer Sameer Agarwal <sameeragarwal@google.com> 1559254601 -0700

Allow Solver::Options::max_num_line_search_step_size_iterations = 0.

This change only affects the TRUST_REGION minimizer and has no effect
on the LINE_SEARCH minimizer.

This options controls the number of iterations that the line search
algorithm performs. The line search algorithm is as the name implies,
used in the LINE_SEARCH minimizer. It is also used by the TRUST_REGION
minimizer when solving bounds constrained optimization problems.

In some bounds constrained problems, it is enough to project each step
onto the bounds constraints and not perform the line search. This can
have a significant impact on runtime. Setting
Solver::Options::max_num_line_search_step_size_iterations = 0 enables
this functionality.

Changchang Wu (ccwu@google.com) came up with the idea for this
implementation.

https://github.com/ceres-solver/ceres-solver/issues/477

Change-Id: Ifbe0bc5c48eedb2c1231d43cd98e4be7316c0682