pcl::PointCloud<pcl::PointXYZI>::Ptr pointcloud_in(new pcl::PointCloud<pcl::PointXYZI>());去掉小于2m以下的点，给出C++代码

Sure! Here is the C++ code to remove points below 2m from a pcl::PointCloud<pcl::PointXYZI>::Ptr named "pointcloud_in":

#include <pcl/point_cloud.h>
#include <pcl/point_types.h>

pcl::PointCloud<pcl::PointXYZI>::Ptr removePointsBelow2m(pcl::PointCloud<pcl::PointXYZI>::Ptr cloud_in)
{
    pcl::PointCloud<pcl::PointXYZI>::Ptr cloud_out(new pcl::PointCloud<pcl::PointXYZI>);

    for (const auto& point : cloud_in->points)
    {
        if (point.z >= 2.0) // Check if the point's z-coordinate is greater than or equal to 2m
        {
            cloud_out->points.push_back(point);
        }
    }

    cloud_out->width = cloud_out->points.size();
    cloud_out->height = 1;
    cloud_out->is_dense = true;

    return cloud_out;
}

int main()
{
    pcl::PointCloud<pcl::PointXYZI>::Ptr pointcloud_in(new pcl::PointCloud<pcl::PointXYZI>);

    // Populate the point cloud with data

    pcl::PointCloud<pcl::PointXYZI>::Ptr pointcloud_filtered = removePointsBelow2m(pointcloud_in);

    // Use the filtered point cloud

    return 0;
}

In this code, the `removePointsBelow2m` function takes a `pcl::PointCloud<pcl::PointXYZI>::Ptr` as input and returns a new filtered point cloud where points below 2m are removed. The function iterates over each point in the input cloud and checks if its z-coordinate is greater than or equal to 2.0. If it is, the point is added to the output cloud.

Please note that you need to populate the `pointcloud_in` with actual data before calling the `removePointsBelow2m` function.