ros下运行报错

问题1：
[pcl_test.launch] is neither a launch file in package [pcl_test] nor is [pcl_test] a launch file name
The traceback for the exception was written to the log file

解决方案：
source devel/setup.sh

问题2：For frame [velodyne]: Fixed Frame [map] does not exist
解决方式：
配置Rviz的Frame为velodyne，并且