Speed up corrector.cc
Remove the Eigen temporary by revealing the columnwise nature
of the computation. This also allows us to get rid of the
special case for nrow = 1.
On problem-356-226730-pre.txt with -robustify evaluation times
change from:
Before:
Residual Evaluations 1.015
Jacobian Evaluations 18.313
After:
Residual Evaluations 1.005
Jacobian Evaluations 8.382
To give a sense of the overhead reduction, compare these numbers
when loss functions are disabled.
Residual Evaluations 0.955
Jacobian Evaluations 7.772
So, this is a 17.5x speedup!
The one dimensional specialization was motivated by denoising.cc.
The evaluation times there are essentially unchanged.
Before:
Residual Evaluations 2.774
Jacobian Evaluations 20.178
After:
Residual Evaluations 2.588
Jacobian Evaluations 19.781
Change-Id: Ic0efbaed75fe4489635039f17189ae24b97802c8
2 files changed
