May 2017 release of OR-Tools

By -
We have just released a new version of OR-Tools on

Release notes:


New directory structure in C++

We have changed the source/include structure of or-tools when using C++. The goal is to provide better encapsulation of the C++ include files. It also has the benefit of aligning the C++ and the python directory structures.
  • src/ has been renamed ortools/.
  • All #include command in C++ files now have the prefix ortools added. #include "constraint/constraint_solver.h" is now #include "ortools/constraint/constraint_solver.h".

New features

Bazel support

You can now build or-tools with bazel, Google's build tool. It works on Linux and Mac OS X. After downloading bazel version 0.4.5 or later, change directory to or-tools and build the examples: bazel build examples/cpp/....

Routing

We have implemented the support for breaks (e.g., vehicle downtime due to drivers eating lunch)in the routing library. This feature is shown in the cvrptw_with_breaks.cc example.

SCIP support

The linear solver wrapper now support SCIP 4.0. You now need to build SCIP first, and then tell or-tools that you will use it. Instructions are available here.

GLPK support

We have also changed the way with build with GLPK. See here.

Cleanups

  • We have removed all usage of hash_map, hash_set in the C++ codebase as they are deprecated. They were replaced by unordered_map and unordered_set from the STL.
  • Cleanup of the C# makefiles, courtesy of Michael Powell.

Comments

  1. John PearsonNovember 24, 2017 at 5:06 AM

    Hello,
    I found this above furnished article very useful having good information regarding route optimization. I would like to have more posts. Thank you.

    ReplyDelete

Post a Comment

Popular posts from this blog

Linking glpk with or-tools on unix

By -
Following the change on SCIP, here is the new procedure to compile and link GLPK with or-tools This currently applies to unix only: First download the latest glpk archive (4.61 at the time of this post). Untar, cd into the glpk directory on linux:   ./configure --prefix=<install_path> --with-pic   make   make install on mac OS X:   ./configure --prefix=<install_path>   make CFLAGS='--mmacosx-version-min=10.8'   make install   then add:   UNIX_GLPK_DIR=<install_path> in or-tools/Makefile.local recompile or-tools:   make clean   make cc test it:   run bin/integer_programming and bin/linear_programming. Both must display glpk runs. I have no easy solution for glpk on windows currently, still investigating.
Read more

Changing the way we link with SCIP

By -
As of today, I pushed support for scip 4.0.0 on both unix and windows. In the process, I have changed the way to setup or-tools to include scip at compilation time. on Unix:   untar the scipoptsuite> archive somewhere   cd <path to scipoptsuite-4.0.0>   Mac OS X:  make GMP=false READLINE=false TPI=tny   Linux:  make GMP=false READLINE=false TPI=tny USRCFLAGS=-fPIC USRCXXFLAGS=-fPIC USRCPPFLAGS=-fPIC   in or-tools, edit Makefile.local   add:     UNIX_SCIP_DIR=<path to sciptopsuite-4.0.0>/scip-4.0.0   make clean   make cc   to test it, run:      bin/integer_programming   it should display the scip solver run. on windows:   download the compiled library:     http://scip.zib.de/download.php?fname=scip-4.0.0.win.x86_64.vc14.opt.spx2.lib.zip   download the headers:      http://scip.zib.de/download/release/scipoptheaders-4.0.0.tgz   uncompress, untar everything.   create a directory that will contains what is needed   md scip-4.0.0  
Read more

Heads up, upcoming incompatibility in the CP/Routing library

By -
Hello all, I will soon push a large incompatible change in the CP and Routing libraries. The change will replace parameters (CP solver parameters, routing model parameters, routing search parameters) from struct to protobuf. This will also hide the C++ command line flags (cp_trace_search, routing_first_solution, ...) and make them redundant for controlling the behavior of the libraries. They are currently kept in the C++ library, but will be dropped out eventually. With this move, all functionalities offered by the C++ command line flags will be available from all languages (provided you implement the command line parsing part). Let's see an example (tsp) Before (in C++):    // Setting first solution heuristic (cheapest addition).    FLAGS_routing_first_solution = "PathCheapestArc";    const Assignment* solution = routing.Solve() ; After (in C++, using the command line flags compatibility) :    RoutingSearchParameters parameters =  BuildSearchParametersFro
Read more