PCL point cloud random sampling by ratio

One 、 Description of algorithm

  PCL Random sampling algorithm in the library pcl::RandomSample Is to enter a fixed number of points , Down sample the original point cloud to a fixed number of points . However, other point cloud Libraries , such as matlab2020b、matlab20212a、matlab2021b etc. , Both are input sampling rate and output sampling result . In order not to appear PCL backward , Also write an implementation by the way .

Two 、 Code implementation

#include <iostream>
#include <random>
#