Commit Graph

40 Commits

Author SHA1 Message Date
Sameer Agarwal a3afe3d724 ClangTidy fixes
Change-Id: I2ed57cd6f84bae81686a833834bf00ddef91f61b
2024-08-09 16:24:07 -07:00
Sameer Agarwal b97ffeadbb Use absl::time
Replace WallTimeInSeconds with absl::Now and use
absl::Time and absl::Duration objects instead of doubles.

wall_time.h/cc -> event_logger.h/cc

Change-Id: I41279961368840fbdf6bb3456ffdbdf2f9bfb85b
2024-08-08 07:18:44 -07:00
Sameer Agarwal 03caeed1c6 ceres/stringprintf -> absl::strings
Replace ceres::String* with their more modern and performant
absl strings library equivalent and delete our string
manipulation library.

Change-Id: Iecbdba9864e0abf329778f81fdc0708f78f7594f
2024-08-08 07:05:23 -07:00
Sameer Agarwal 57e26182f3 Add more missing headers
Change-Id: I35875ca856b7b80c622562a1c14b4c8ced10f740
2024-07-18 11:37:07 -07:00
Sameer Agarwal 5a30cae583 Preparing for 2.2.0rc1
1. Add a version history
2. Update copyright years across the code base
3. Run format_all.sh
4. Update version strings from 2.1.0 to 2.2.0 in the docs and
   elsewhere.

Change-Id: I46d8d479d54bd6002d532785e67342106e73c9ac
2023-09-21 11:23:38 -07:00
Sameer Agarwal ee90f6cbf7 Detect large Jacobians and return failure instead of crashing.
Detect when the number of non-zeros overflows when constructing
BlockSparseMatrix and CompressedRowSparseMatrix and return
with an error message instead of crashing.

Change-Id: I45e102f7c0519eef441ce0586b7adf96e4a954a9
2023-08-11 17:16:28 -07:00
Sameer Agarwal 749a442d97 Clang-Tidy fixes
Change-Id: I58900a452591315a39754b329e94b315c34926cd
2023-01-16 07:38:05 -08:00
Sameer Agarwal 9602ed7b76 ClangFormat changes
Change-Id: I88c9e38b0450aed26c60e1dd54964ab6571e3eef
2023-01-14 05:54:24 -08:00
Alexander Ivanov 53df5ddcfd Removing using std::...
Change-Id: I584402e2a34869183c1d59071a15d97b216c52fb
2023-01-11 16:51:38 +00:00
Dmitriy Korchemkin b158515089 Parallel operations on vectors
Main focus of this change is to parallelize remaining operations (most of them
are operations on vectors) in code-path utilized with iterative Schur
complement.

Parallelization is handled using lazy evaluation of Eigen expressions.

On linux pc with intel 8176 processor parallelization of vector operations has
the following effect:

Running ./bin/parallel_vector_operations_benchmark
Run on (112 X 3200.32 MHz CPU s)
CPU Caches:
  L1 Data 32 KiB (x56)
  L1 Instruction 32 KiB (x56)
  L2 Unified 1024 KiB (x56)
  L3 Unified 39424 KiB (x2)
Load Average: 3.30, 8.41, 11.82
-----------------------------------
Benchmark                      Time
-----------------------------------
SetZero                 10009532 ns
SetZeroParallel/1       10024139 ns
...
SetZeroParallel/16        877606 ns

Negate                   4978856 ns
NegateParallel/1         5145413 ns
...
NegateParallel/16         721823 ns

Assign                  10731408 ns
AssignParallel/1        10749944 ns
...
AssignParallel/16        1829381 ns

D2X                     15214399 ns
D2XParallel/1           15623245 ns
...
D2XParallel/16           2687060 ns

DivideSqrt               8220050 ns
DivideSqrtParallel/1     9088467 ns
...
DivideSqrtParallel/16     905569 ns

Clamp                    3502010 ns
ClampParallel/1          4507897 ns
...
ClampParallel/16          759576 ns

Norm                     4426782 ns
NormParallel/1           4442805 ns
...
NormParallel/16           430290 ns

Dot                      9023276 ns
DotParallel/1            9031304 ns
...
DotParallel/16           1157267 ns

Axpby                   14608289 ns
AxpbyParallel/1         14570825 ns
...
AxpbyParallel/16         2672220 ns
-----------------------------------

Multi-threading of vector operations in ISC and program evaluation results into
the following improvement:

Running ./bin/evaluation_benchmark
--------------------------------------------------------------------------------------
Benchmark                                                               this   2fd81de
--------------------------------------------------------------------------------------
Residuals<problem-13682-4456117-pre.txt>/1                           4136 ms   4292 ms
Residuals<problem-13682-4456117-pre.txt>/2                           2919 ms   2670 ms
Residuals<problem-13682-4456117-pre.txt>/4                           2065 ms   2198 ms
Residuals<problem-13682-4456117-pre.txt>/8                           1458 ms   1609 ms
Residuals<problem-13682-4456117-pre.txt>/16                          1152 ms   1227 ms

ResidualsAndJacobian<problem-13682-4456117-pre.txt>/1               19759 ms  20084 ms
ResidualsAndJacobian<problem-13682-4456117-pre.txt>/2               10921 ms  10977 ms
ResidualsAndJacobian<problem-13682-4456117-pre.txt>/4                6220 ms   6941 ms
ResidualsAndJacobian<problem-13682-4456117-pre.txt>/8                3490 ms   4398 ms
ResidualsAndJacobian<problem-13682-4456117-pre.txt>/16               2277 ms   3172 ms

Plus<problem-13682-4456117-pre.txt>/1                                 339 ms    322 ms
Plus<problem-13682-4456117-pre.txt>/2                                 220 ms
Plus<problem-13682-4456117-pre.txt>/4                                 128 ms
Plus<problem-13682-4456117-pre.txt>/8                                78.0 ms
Plus<problem-13682-4456117-pre.txt>/16                               49.8 ms

ISCRightMultiplyAndAccumulate<problem-13682-4456117-pre.txt>/1       2434 ms   2478 ms
ISCRightMultiplyAndAccumulate<problem-13682-4456117-pre.txt>/2       2706 ms   2688 ms
ISCRightMultiplyAndAccumulate<problem-13682-4456117-pre.txt>/4       1430 ms   1548 ms
ISCRightMultiplyAndAccumulate<problem-13682-4456117-pre.txt>/8        742 ms    883 ms
ISCRightMultiplyAndAccumulate<problem-13682-4456117-pre.txt>/16       438 ms    555 ms

ISCRightMultiplyAndAccumulateDiag<problem-13682-4456117-pre.txt>/1   2438 ms   2481 ms
ISCRightMultiplyAndAccumulateDiag<problem-13682-4456117-pre.txt>/2   2565 ms   2790 ms
ISCRightMultiplyAndAccumulateDiag<problem-13682-4456117-pre.txt>/4   1434 ms   1551 ms
ISCRightMultiplyAndAccumulateDiag<problem-13682-4456117-pre.txt>/8    765 ms    892 ms
ISCRightMultiplyAndAccumulateDiag<problem-13682-4456117-pre.txt>/16   435 ms    559 ms

JacobianSquaredColumnNorm<problem-13682-4456117-pre.txt>/1           1278 ms
JacobianSquaredColumnNorm<problem-13682-4456117-pre.txt>/2           1555 ms
JacobianSquaredColumnNorm<problem-13682-4456117-pre.txt>/4            833 ms
JacobianSquaredColumnNorm<problem-13682-4456117-pre.txt>/8            459 ms
JacobianSquaredColumnNorm<problem-13682-4456117-pre.txt>/16           250 ms

JacobianScaleColumns<problem-13682-4456117-pre.txt>/1                1468 ms
JacobianScaleColumns<problem-13682-4456117-pre.txt>/2                1871 ms
JacobianScaleColumns<problem-13682-4456117-pre.txt>/4                 957 ms
JacobianScaleColumns<problem-13682-4456117-pre.txt>/8                 528 ms
JacobianScaleColumns<problem-13682-4456117-pre.txt>/16                294 ms

End-to-end improvements with bundle_adjuster invoked with
./bin/bundle_adjuster --num_threads 28 --num_iterations 40 \
                      --linear_solver iterative_schur \
                      --preconditioner jacobi --input
---------------------------------------------
Problem                         this  2fd81de
---------------------------------------------
problem-13682-4456117-pre.txt  508.6    892.7
problem-1778-993923-pre.txt    763.8   1129.9
problem-1723-156502-pre.txt      6.3     14.4
problem-356-226730-pre.txt      76.3    116.2
problem-257-65132-pre.txt       38.6     52.0

Change-Id: Ie31cc5015f13fa479c16ffb5ce48c9b880990d49
2022-12-17 02:52:27 +03:00
Joydeep Biswas 829089053e CUDA CGNR, Part 4: CudaCgnrSolver
* Added CudaCgnrSolver, a new CUDA-accelerated CGNR.
* To use CudaCgnrSolver, the user must select CGNR as the linear_solver
  and CUDA_SPARSE as the sparse_linear_algebra_library.
* Updated ConjugateGradientSolver to work with an array of pointers to
  scratch to support CudaVectors as scratch.
* Moved CUDA initialization to run in Solver::Solve as needed.

Some performance comparisons on an Ubuntu 20.04 desktop with an
Intel i9-9940X CPU @ 3.30GHz, and an nVidia Quadro RTX 6000,
all configurations run with 24 threads, and 10 iterations.

=================================================
CGNR + CUDA_SPARSE + IDENTITY Preconditioner
problem-1778-993923-pre.txt
=================================================
Cost:
Initial                          2.563973e+08
Final                            1.724755e+06
Change                           2.546725e+08

Minimizer iterations                       11
Successful steps                            7
Unsuccessful steps                          4

Time (in seconds):
Preprocessor                         4.020158

  Residual only evaluation           1.567092 (10)
  Jacobian & residual evaluation     7.847130 (7)
  Linear solver                     31.688898 (10)
Minimizer                           46.834987

Postprocessor                        0.353974
Total                               51.209120

=================================================
SPARSE_SCHUR (CPU) + SUITE_SPARSE + AMD
problem-1778-993923-pre.txt
=================================================
Cost:
Initial                          2.563973e+08
Final                            1.651617e+06
Change                           2.547457e+08

Minimizer iterations                       11
Successful steps                           11
Unsuccessful steps                          0

Time (in seconds):
Preprocessor                        35.812003

  Residual only evaluation           1.658980 (10)
  Jacobian & residual evaluation    12.218799 (11)
  Linear solver                     76.409992 (10)
Minimizer                           98.809773

Postprocessor                        0.372712
Total                              134.994489

=================================================
ITERATIVE_SCHUR (CPU) + JACOBI Preconditioner
problem-1778-993923-pre.txt
=================================================
Cost:
Initial                          2.563973e+08
Final                            1.684447e+06
Change                           2.547128e+08

Minimizer iterations                       11
Successful steps                            8
Unsuccessful steps                          3

Time (in seconds):
Preprocessor                        15.331614

  Residual only evaluation           1.606114 (10)
  Jacobian & residual evaluation     8.502166 (8)
  Linear solver                    351.910080 (10)
Minimizer                          368.797327

Postprocessor                        0.363536
Total                              384.492478

=================================================
CGNR + CUDA_SPARSE + IDENTITY Preconditioner
problem-13682-4456117-pre.txt
=================================================
Cost:
Initial                          1.126372e+09
Final                            2.269329e+07
Change                           1.103678e+09

Minimizer iterations                       11
Successful steps                            7
Unsuccessful steps                          4

Time (in seconds):
Preprocessor                        19.140087

  Residual only evaluation           8.721920 (10)
  Jacobian & residual evaluation    41.955923 (7)
  Linear solver                    214.121861 (10)
Minimizer                          296.636890

Postprocessor                        1.971827
Total                              317.748804

Change-Id: I3a09f31aa6903f661e91f595afd39d427583e856
2022-08-15 23:44:34 -05:00
Sameer Agarwal 2c78c5f339 Small naming fixups.
use_power_series_expansion_initialization -> use_spse_initialization
max_linear_solve_iterations -> max_linear_solver_iterations

Change-Id: I7775fa9b1ad12e28c8d01d44349b7eaef9b57edd
2022-08-13 11:59:16 -07:00
Mark Shachkov 92d8379532 Enable usage of schur power series expansion preconditioner.
Add an option to use schur power series expansion for initialization
of pcg solution in ITERATIVE_SCHUR linear solver.

Change-Id: Ifb8bce02bc5f5ceebc74f961eefd3f6dd2ffab4a
2022-08-13 21:05:11 +03:00
Sameer Agarwal 8ba8fbb173 Remove Solver::Options::use_postordering
This was an ill-advised and complicated to interpret option
which offers nothing particularly useful.

Change-Id: Ia7741ed62ef977c96fa52299a884e404bee659ac
2022-05-19 21:10:33 +00:00
Sameer Agarwal 39ec5e8f99 Add Nested Dissection based fill reducing ordering
With this change, the user can now choose between Approximate Minimum
Degree and Nested Dissection as a fill reducing algorithm when using
a sparse direct factorization based linear solver like SPARSE_NORMAL_CHOLESKY
or SPARSE_SCHUR.

Currenly only SUITE_SPARSE is supported. It requires that
SuiteSparse be compiled with Metis support enabled.

On most problems AMD is still the better choice, but in some cases
like the grid3D dataset from https://lucacarlone.mit.edu/datasets/
the solution time with AMD is 57s and with NESDIS 38 on my M1 Mac.

On some other problems at Google we have observed speedups of 10x,
there is also a corresponding decrease in the total amount of memory
used.

This patch is based on the original work done by NeroBurner in
https://ceres-solver-review.googlesource.com/c/ceres-solver/+/20580

1. Add a new enum to the public api LinearSolverOrderingType and
   a setting Solver::Options::linear_solver_ordering_type.
2. TrustRegionPreprocessor had some complicated logic which determined
   when linear solvers should reorder their matrices on their own and not
   this has been refactored into a more readable function that lives
   inside reorder_program.h/cc.
3. Plumbing in reorder_program.cc and trust_region_processor.cc to use
   nested dissection.
4. Update bundle_adjuster.cc to use nested dissection.

Change-Id: I388b027934f86c58b4da2b65a4fa5204ea73bf40
2022-05-19 12:36:20 -07:00
Sameer Agarwal 41c5fb1e80 Refactor suitesparse.h/cc
1. Generalize SuiteSparse::AnalyzeCholesky and
   SuiteSparse::BlockAnalyzeCholesky from just doing AMD to taking
   OrderingType as an argument and using that to determine whether
   AMD & Nested Dissection algorithms are used for computing the
   fill-reducing ordering or a natural ordering when computing
   the symbolic factorization.

2. Remove AnalyzeCholeskyWithNaturalOrdering.

3. Replace and generalize SuiteSparse::BlockAMDOrdering with
   SuiteSparse::BlockOrdering which also takes OrderingType as an
   argument. Same for SuiteSparse::ApproximateMinimumDegreeOrdering
   and SuiteSparse::NestedDissectionOrdering by
   SuiteSparse::Ordering.

4. Remove LinearSolver::Options::use_postordering and replace it
   with LinearSolver::Options::ordering_type.

5. Replace Preconditioner::Options::use_postordering and replace it
   with Preconditioner::Options::ordering_type.

6. Add NESDIS to OrderingType. With the above changes, the linear
   solvers can now use Nested Dissection once this information
   is piped through the nonlinear solver.

Change-Id: Ib8e93fbf34ae2981bf2ac54dcda9e25c7c213790
2022-05-19 11:05:46 -07:00
Sameer Agarwal 12263e2830 Make the min. required version of SuiteSparse to be 4.5.6
With this change we can drop the complicated/conditional handling
around CAMD and assume that it is always available.

Change-Id: I93e1da676fb75817f79824b8b2b6549d03f278b0
2022-05-16 12:48:43 -07:00
Sameer Agarwal caf614a6c1 Modernize code using c++17 constructs
Mostly done using

find . \( -name '*.cc' -o -name '*.h' \) -a -type f -exec clang-tidy -p \
cmake-build -checks='-*,google-*,modernize-*,-modernize-use-nodiscard,-modernize-use-trailing-return-type' {} -fix \;

Change-Id: Ifccbcabe7a1d9a32a09d28ac4f3f8466696c1a50
2022-04-22 06:11:18 -07:00
Sergiu Deitsch c8658c8992 Modernize more
Apply clang-tidy Google and modernize fixes without trailing return type
using:

$ clang-tidy -p <build-dir> \
  -checks='-*,google-*,modernize-*,-modernize-use-trailing-return-type' {} -fix

Change-Id: I7450cc58ea9abf928f73a467e87876083217fa26
2022-02-26 22:16:56 +00:00
Sergiu Deitsch f90833f5fa Simplify symbol export
Currently, the logic for exporting symbols is rather complicated: when
tests are enabled internal symbols are exported in addition to the
public symbols. Such logic causes several problems. (1) Test binaries
link against a Ceres build that is different from the final release
since fewer optimizations are applied if more symbols are exported. (2)
Also, some toolchains hide symbols by default breaking the existing
logic eventually causing linker errors.

Since internal symbols are not intended to be used outside of the
project, we can compile them into object files and use exactly the same
binary code both for the final build and the tests without relying on
conditionals.

By default, all symbols are now hidden unless annotated as public.
Internal symbols are explicitly marked as not being exported in case
users chose not to hide symbols by default.

Change-Id: I589dd10be2f6f438508783cf99d141af0120057b
2022-02-14 20:19:08 +01:00
Sameer Agarwal ae65219e04 ClangTidy cleanups
1. NULL -> nullptr
2. foo.reset(new Bar) -> = foo = std::make_unique<Bar>()
3. Missing std library includes & prefixes

Change-Id: I260b261b484554be681ee5a7398126fdb3b3a789
2022-02-09 10:06:49 -08:00
Sergiu Deitsch a35bd1bf90 Use = default for trivial special members
Applied changes correspond to clang-tidy fixes
stemming from the modernize-use-equals-default check.

Change-Id: I254b0908a76d464131564b637cd0e42a6b03fb5a
2022-02-09 18:38:52 +01:00
Sameer Agarwal 8bfdb02fb1 Rewrite uses of VLOG_IF and LOG_IF.
VLOG_IF's evaluation order is ambiguous - does it mean
`if (cond) VLOG(lvl)` or `if (VLOG_IS_ON(lvl) && cond) LOG(INFO)`?
In particular, the way it works now is inconsistent with the way the
rest of the LOG macros evaluate their arguments.
Fixing this would be hard, and the macro's behavior would still surprise
some people. Replacing it with an if statement is simple, clear, and unambiguous.

Change-Id: I97a92d17a932c0a5344a1bf98d676308793ba877
2020-10-12 18:34:24 +00:00
Sameer Agarwal a614f788a3 Call EvaluationCallback before evaluating the fixed cost.
Fixe a subtle bug in Program::RemoveFixedBlocks, where we call
ResidualBlock::Evaluate on residual blocks with all constant parameter
blocks without paying attention to the presence of an
EvaluationCallback.

In the process also run clang-format on some of the files touched by
this change.

https://github.com/ceres-solver/ceres-solver/issues/482

Change-Id: I342b66f6f975fdee2eef139a31f24d4a3e568e84
2020-05-27 22:19:16 -07:00
Sameer Agarwal f66b513826 Fix some clang-tidy warnings.
Change-Id: Ic71bf0fc561edc22e3051d156fac630fcfea5d92
2019-07-15 13:23:04 -07:00
Sameer Agarwal 487c1aa51f Expose SubsetPreconditioner in the API
https://github.com/ceres-solver/ceres-solver/issues/270

Detailed list of changes:

1. Add SUBSET to the PreconditionerType enum.
2. Add Solver::Options::residual_blocks_for_subset_preconditioner
3. Integrate SubsetPreconditioner into the CGNR solver.
4. Add the reordering logic needed for this to TrustRegionPreprocessor.
5. Expect CreateJacobianBlockTranspose to take the starting row block
   so that we can work with subparts of the Jacobian matrix.
6. Extend the denoising example to use this preconditioner.

As an illustration of its performance, we consider the performance of
denoising -input ../data/ceres_noisy.pgm  --foe_file ../data/5x5.foe

tl;dr

For the same cost,

SPARSE_NORMAL_CHOLESKY -  81s
CGNR + JACOBI          - 718s
CGNR + SUBSET          -  57s

SPARSE_NORMAL_CHOLESKY
======================

Cost:
Initial                          2.317806e+05
Final                            2.232323e+04
Change                           2.094574e+05

Minimizer iterations                       10
Successful steps                           10
Unsuccessful steps                          0

Time (in seconds):
Preprocessor                         2.999746

  Residual only evaluation           2.306811 (10)
  Jacobian & residual evaluation     7.421727 (10)
  Linear solver                     65.517273 (10)
Minimizer                           78.731011

Postprocessor                        0.026079
Total                               81.756836

Termination:                      CONVERGENCE (Function tolerance reached. |cost_change|/cost: 8.573046e-04 <= 1.000000e-03)

CGNR + JACOBI
=============
Cost:
Initial                          2.317806e+05
Final                            2.232344e+04
Change                           2.094572e+05

Minimizer iterations                       10
Successful steps                           10
Unsuccessful steps                          0

Time (in seconds):
Preprocessor                         0.648814

  Residual only evaluation           2.297607 (10)
  Jacobian & residual evaluation     7.327886 (10)
  Linear solver                    699.601248 (10)
Minimizer                          712.419493

Postprocessor                        0.024014
Total                              713.092321

Termination:                      CONVERGENCE (Function tolerance reached. |cost_change|/cost: 8.528538e-04 <= 1.000000e-03)

CGNR + SUBSET (random 20% residuals used for the preconditioner)
===============================================================
Cost:
Initial                          2.317806e+05
Final                            2.232327e+04
Change                           2.094574e+05

Minimizer iterations                       10
Successful steps                           10
Unsuccessful steps                          0

Time (in seconds):
Preprocessor                         1.472743

  Residual only evaluation           2.428315 (10)
  Jacobian & residual evaluation     7.367796 (10)
  Linear solver                     42.585999 (10)
Minimizer                           55.664459

Postprocessor                        0.024098
Total                               57.161301

Termination:                      CONVERGENCE (Function tolerance reached. |cost_change|/cost: 8.538277e-04 <= 1.000000e-03)

Change-Id: Ifb011408bd53edbb9439b0b7345649a38f999e18
2019-07-12 16:08:36 +02:00
Sameer Agarwal bf709ecac2 Move EvaluationCallback from Solver::Options to Problem::Options.
Adding it to Solver::Options was a mistake, as it prevents it from
being used in covariance estimation. Also updated associated docs.

https://github.com/ceres-solver/ceres-solver/issues/380
https://github.com/ceres-solver/ceres-solver/issues/401
https://github.com/ceres-solver/ceres-solver/issues/484

Change-Id: I63809a47a58e84c04a58bf8e59ace92f45fc2873
2019-07-08 21:24:08 +02:00
Sameer Agarwal 94712db5c7 Convert calls to CHECK_NOTNULL to CHECK.
CHECK_NOTNULL is being deprecated and removed from the
glog library.

Change-Id: I4a6d1eec6e82a768c7861c8f776bf1f9c0b50c74
2018-08-28 08:14:19 -07:00
Sameer Agarwal f973e107d2 Enable mixed precision solves.
1. Add Solver::Options::use_mixed_precision_solves,
   and Solver::Options::max_num_refinement_iterations.
2. Make SparseCholesky::Create return a unique_ptr.
3. SparseCholesky::Create now takes LinearSolver::Options
   as an argument.
4. IterativeRefiner's constructor does not require num_cols
   as an argument.
5. SparseNormalCholeskySolver now uses a separate rhs vector.

This basic implementation results in a 10% reduction in solver time
and 30% reduction in linear solver memory usage.

Change-Id: I6830f32cae2febf082d2733262eb2c9f0482b0ea
2018-04-10 11:01:38 -07:00
Keir Mierle 7bdceb46cf Evaluation callback API
This adds a callback mechanism to for users to get notified just
before jacobian and residual evaluations. This will enable
aggressive caching and sharing of compute between cost functions.

Change-Id: I67993726920218edf71ab9ae70c34c204756c71a
2018-03-07 12:41:22 -08:00
Sameer Agarwal 3d933750a7 Deprecate Solver::Options::num_linear_solver_threads
1. Solver::Options::num_threads now controls parallelism in Ceres
   Solver. The user specified value of
   Solver::Options::num_linear_solver_threads is ignored.
2. If the user specifies Solver::Options::num_linear_solver_threads
   and it is different from Solver::Options::num_threads,
   a warning is printed.
3. Solver::Summary:num_linear_solver_threads_given and
   Solver::Summary::num_linear_solver_threads_used are also
   deprecated and are always set to Solver::Summary::num_threads_given
   and Solver::Summary::num_threads_used.

Change-Id: I20b9336d9336e400e6f0a15b63857c0c43eb271c
2018-02-27 20:38:05 -08:00
Mike Vitus f408f89e8b Adds a Ceres Context structure.
A Ceres Context holds common global state that can be re-used within
Ceres.  The Context current contains a thread pool if compiling with
C++11 threading support.  Threads are expensive to create and destroy so
it is good to maintain across multiple Ceres solves.

Tested by compiling with and without TBB support and ran unit tests. Ran
bazel as well.

Change-Id: I82f598dfae642aa0e81a6039dc174608a5e8dbfb
2018-02-26 10:37:53 -08:00
Sameer Agarwal 1182fc2884 SPARSE_SCHUR + CX_SPARSE = Faster
There was a bug in the trust region preprocessor where no fill
reducing ordering was computed for the case of SPARSE_SCHUR + CX_SPARSE
but this was not signaled to SchurComplementSolver, so it was using
a naive/natural ordering. To fix this two changes are made:

1. TrustRegionProcessor's logic for signaling the ordering to the
   linear solver has been re-worked. The surrounding code has also
   been re-organized for better readability.
2. In SchurComplementSolver::SolveReducedSystem the row and column
   block structure has been added to the CompressedRowSparseMatrix
   containing the Schur complement so that block AMD can be used.

As a result of these changes the linear solve time for
problem-744-543562-pre.txt has been brought down from 58 seconds to
35 seconds.

Change-Id: I4d82efce05175260f97b1f925f8a1b4a9d650cae
2017-06-20 09:13:02 -07:00
Keir Mierle 7492b0d8de Update copyright headers with new year and URL
Since Ceres is moving to using GitHub for issues, and the Google
Code URL in the current copyright header will soon become invalid,
update all the headers.

Change-Id: I1fce70375d1bcf098591f07b4d8f01a5c1e0789c
2015-03-18 05:43:23 +00:00
Sameer Agarwal 05a07ecc77 Remove using std::string from port.h
Change-Id: I7376f5e7eace22ec1fc05a61eaa858594f08682d
2015-01-07 15:10:46 -08:00
Sameer Agarwal bcc865f81c Remove using namespace std;
For historical reasons we had a "using namespace std;" in port.h. This
is generally a bad idea. So removing it and along the way doing a bunch
of cpplint cleanup.

Change-Id: Ia125601a55ae62695e247fb0250df4c6f86c46c6
2015-01-07 14:26:53 -08:00
Sameer Agarwal b44cfdef25 Let ITERATIVE_SCHUR use an explicit Schur Complement matrix.
Up till now ITERATIVE_SCHUR evaluates matrix-vector products
between the Schur complement and a vector implicitly by exploiting
the algebraic expression for the Schur complement.

This cost of this evaluation scales with the number of non-zeros
in the Jacobian.

For small to medium sized problems there is a sweet spot where
computing the Schur complement is cheap enough that it is much
more efficient to explicitly compute it and use it for evaluating
the matrix-vector products.

This changes implements support for an explicit Schur complement
in ITERATIVE_SCHUR in combination with the SCHUR_JACOBI preconditioner.

API wise a new bool Solver::Options::use_explicit_schur_complement
has been added.

The implementation extends the SparseSchurComplementSolver to use
Conjugate Gradients.

Example speedup:

use_explicit_schur_complement = false

Time (in seconds):
Preprocessor                            0.585

  Residual evaluation                   0.319
  Jacobian evaluation                   1.590
  Linear solver                        25.685
Minimizer                              27.990

Postprocessor                           0.010
Total                                  28.585

use_explicit_schur_complement = true

Time (in seconds):
Preprocessor                            0.638

  Residual evaluation                   0.318
  Jacobian evaluation                   1.507
  Linear solver                         5.930
Minimizer                               8.144

Postprocessor                           0.010
Total                                   8.791

Which indicates an end-to-end speedup of more than 3x, with the linear
solver being sped up by > 4x.

The idea to explore this optimization was inspired by the recent paper:

Mining structure fragments for smart bundle adjustment
L. Carlone, P. Alcantarilla, H. Chiu, K. Zsolt, F. Dellaert
British Machine Vision Conference, 2014

which uses a more complicated algorithm to compute parts of the
Schur complement to speed up the matrix-vector product.

Change-Id: I95324af0ab351faa1600f5204039a1d2a64ae61d
2014-09-29 10:29:32 -07:00
Sameer Agarwal 8de27be218 Fix a bug in TrustRegionPreprocessor
TrustRegionPreprocessor was not setting Minimizer::Options::is_constrained.
This meant that the line search for bounds constraints was not being
invoked for bounds constrained problems.

And some minor lint cleanup.

Change-Id: I18852cfaf1b33fd90b7d8c196f2063c128126658
2014-08-19 08:39:48 -07:00
Sameer Agarwal bd90384226 Lint comments from William Rucklidge.
Also some minor refactoring of the trust_region_preprocessor_test.cc

Change-Id: Ica28002254c95722faf93a7ef35bf3deab557f0b
2014-08-18 11:27:06 -07:00
Sameer Agarwal f7da411ef0 Preprocessor for the TrustRegionMinimizer.
1. Base class for preprocessors.
2. A preprocessor for problems that will be solved using
   the trust region minimizer.
3. Added sanity tests to the program reordering options
   for Schur type linear solvers.
4. Tests for the TrustRegionPreprocessor.

Change-Id: I88cd926f0053bbbf2bd6b11e03ec55b8bf473cf1
2014-08-12 21:58:25 -07:00