./configure --prefix=$HOME --with-toolbox=$HOME/toolbox/ --with-boost=/opt/local/include/ CXXFLAGS=" -pipe -g -O2 -march=core2 -DNDEBUG" --disable-static
based on reading From http://www.gentoo.org/doc/en/gcc-optimization.xml, including:
-O2: A step up from -O1. This is the recommended level of optimization unless you have special needs. -O2 will activate a few more flags in addition to the ones activated by -O1. With -O2, the compiler will attempt to increase code performance without compromising on size, and without taking too much compilation time.
-O3: This is the highest level of optimization possible, and also the riskiest. It will take a longer time to compile your code with this option, and in fact it should not be used system-wide with gcc 4.x. The behavior of gcc has changed significantly since version 3.x. In 3.x, -O3 has been shown to lead to marginally faster execution times over -O2, but this is no longer the case with gcc 4.x. Compiling all your packages with -O3 will result in larger binaries that require more memory, and will significantly increase the odds of compilation failure or unexpected program behavior (including errors). The downsides outweigh the benefits; remember the principle of diminishing returns. Using -O3 is not recommended for gcc 4.x.
This is a big edit but with no templates involed, so it should not be a big deal.
New namespace gtsam::noiseModel collects all noise models, which provide efficient whitening and chain-rule implementation needed for optimization. The class hierarchy gives us the ability to use models from full covariances to i.i.d. unit variance noise with a single interface, where the latter will be much cheaper.
From now on, all non-linear factors take a shared_ptr to a Gaussian noise model. This is done through the parameter (const sharedGaussian& model). The use of a shared pointer allows us to share one noise models for thousands of factors, if applicable.
Just like Richard's Symbol change, there is a compile flag GTSAM_MAGIC_GAUSSIAN which allows you to use doubles, vectors, or matrices to created noise models on the fly. You have to set it to the correct dimension. Use of this is *not* encouraged and the flag will disappear after some good soul fixed all unit tests.
Kai Ni
Frank Dellaert
Chris Beall
Richard Roberts