tree 5efbf3f94dd6e77ff6a2b03161670ae1b7d1ec92
parent 1fd0be916dd4ff4241bd52264b9e9170bc7e4339
author Sameer Agarwal <sameeragarwal@google.com> 1601316779 -0700
committer Sameer Agarwal <sameeragarwal@google.com> 1601320785 -0700

Fix a logging bug in TrustRegionMinimizer.

Upon encountering an unsuccessful step (one where the cost goes up)
the the trust region minimizer failed to populate the gradient norm
in the IterationSummary. This would cause the gradient norm to be
logged as zero which is incorrect. Instead it should be the gradient
norm at the current point.

This CL fixes this issue.

Before:
iter      cost      cost_change  |gradient|   |step|    tr_ratio  tr_radius  ls_iter  iter_time  total_time
   0  1.115206e+07    0.00e+00    1.90e+07   0.00e+00   0.00e+00  1.00e+04        0    2.72e-01    1.33e+00
   1  3.687552e+06    7.46e+06    1.84e+08   2.86e+03   6.91e-01  1.06e+04        1    1.32e+00    2.65e+00
   2  3.670266e+10   -3.67e+10    0.00e+00   3.27e+03  -1.07e+04  5.30e+03        1    7.52e-01    3.40e+00
   3  4.335397e+07   -3.97e+07    0.00e+00   2.74e+03  -1.16e+01  1.32e+03        1    7.28e-01    4.13e+00
   4  1.345488e+06    2.34e+06    4.12e+07   1.55e+03   6.87e-01  1.40e+03        1    9.31e-01    5.06e+00
   5  5.376653e+05    8.08e+05    9.99e+06   6.64e+02   7.46e-01  1.59e+03        1    9.64e-01    6.03e+00

After:
iter      cost      cost_change  |gradient|   |step|    tr_ratio  tr_radius  ls_iter  iter_time  total_time
   0  1.115206e+07    0.00e+00    1.90e+07   0.00e+00   0.00e+00  1.00e+04        0    2.37e-01    1.13e+00
   1  3.687552e+06    7.46e+06    1.84e+08   2.86e+03   6.91e-01  1.06e+04        1    1.08e+00    2.21e+00
   2  3.670266e+10   -3.67e+10    1.84e+08   3.27e+03  -1.07e+04  5.30e+03        1    7.50e-01    2.96e+00
   3  4.335397e+07   -3.97e+07    1.84e+08   2.74e+03  -1.16e+01  1.32e+03        1    7.13e-01    3.67e+00
   4  1.345488e+06    2.34e+06    4.12e+07   1.55e+03   6.87e-01  1.40e+03        1    9.01e-01    4.57e+00
   5  5.376653e+05    8.08e+05    9.99e+06   6.64e+02   7.46e-01  1.59e+03        1    9.36e-01    5.51e+00

Change-Id: Iae538fe089be07c7bb219337a6f1392f7213acfe