Function prune

include/Eigen/Eigen/src/SparseCore/SparseVector.h:212–214

\copydoc SparseMatrix::prune(const Scalar&,const RealScalar&) */

    /** \copydoc SparseMatrix::prune(const Scalar&,const RealScalar&) */
    Index prune(const Scalar& reference, const RealScalar& epsilon = NumTraits<RealScalar>::dummy_precision()) {
      return prune([&](const Scalar& val){ return !internal::isMuchSmallerThan(val, reference, epsilon); });
    }

    /**
     * \brief Prunes the entries of the vector based on a `predicate`