copy a pointcloud but just copy a part of points data [closed]

edit

I want to copy a pointcloud to do transformpointCloud, but the data from pointcloud is too much, so I want to pickup one every 25 data.

pcl::PointCloud<pcl::PointXYZ>::Ptr simpleCloud(new pcl::PointCloud<pcl::PointXYZ>);
int cloudsize = (int)ceil((outputCloud1 -> width) * (outputCloud1 -> height)*1.0/25.0);
simpleCloud ->width =outputCloud1->width;
simpleCloud ->height =outputCloud1->height;
simpleCloud ->is_dense =outputCloud1->is_dense;
//simpleCloud ->sensor_origin_ =outputCloud1->sensor_origin_;
//simpleCloud ->sensor_orientation_ =outputCloud1->sensor_orientation_;
for(int i=0; i<cloudsize;i++)
   {

      simpleCloud ->points[i] = outputCloud1 -> points[i*25];

    }

Then everytime I launch this code, node died. Does anybody give me suggestions? Thanks very much.

I find solution in answer