sci Ceres Solver is a portable C++ library that allows for modeling and solving large complicated nonlinear least squares problems. It features: * automatic differentiation * robust loss functions * local parameterizations * threaded Jacobian evaluators and linear solvers * Levenberg-Marquardt and Dogleg (Powell, Subspace) solvers * Dense QR and Cholesky factorization (using Eigen) for small problems * Sparse Cholesky factorization (using SuiteSparse) for large sparse problems * Specialized solvers for bundle adjustment problems in computer vision * Iterative linear solvers for general sparse and bundle adjustment problems Enable simple support for sparse matrix algebra from sci-libs/cxsparse with no LAPACK dependencies Enable fixed-size schur specializations (disable if binary size is an issue) Use METIS via sci-libs/cholmod for matrix partitioning Enable support for sparse matrix algebra with various packages from SuiteSparse Use dev-cpp/gflags for flag parsing Use dev-libs/protobuf to encode structured data