finds position of least significant unset bit */

* @brief Calculating the Russian Roulette survival probability using the Guided/Adjoint-driven RR strategy. * * This function implements the Guided/

@brief If the samples originates from a surface event.

Constructor: takes a const ref to the matrix object with the data points

Deleted copy constructor*/

* KDTree constructor * * Refer to docs in README.md or online in * https://github.com/jlblancoc/nanoflann * * The KD-Tree poi

* KDTree constructor * * Refer to docs in README.md or online in * https://github.com/jlblancoc/nanoflann * * The KD-Tree poi

! default matrix constructor */

MemoryMappedFile's constructor tries to map memory to a file. If this succeeds, valid() will return true and all fields are usable; otherwise, valid()