# kinect PointCloud2 differs in rviz and numpy array plot, redundant data in PointCloud2? [closed]

I need an numpy array with the xz coordinates in an certain y-range for an obstacle avoidance from the Kinect pointCloud2 Data. I wrote a test program and compared it with the rviz output. Now I am a little confused about the result. Can someone explain to me the array plot on the left?

Thank you very much!

Picture:

left: plot of np.array

right: rviz (TopDownOrtho)

test code

```
def callback_kinectPointCloud(data):
# data '/camera/depth/points', PointCloud2
a = np.fromstring(data.data, dtype=np.float32)
b = a.reshape((-1,3))
# Filter data
#d = b[ np.where( b[:,1] < robot_height_kinect),:][0]
e =b [:,(0,2)]
plt.plot(*np.transpose(e), marker=',', color='r', ls='')
plt.show()
```