-4
-2
0
2
4
-4
-3
-2
-1
0
1
2
3
4
-1
-0.5
0
0.5
1
-2
-1
0
1
2
0
5
10
15
20
25
30
0
0.2
0.4
0.6
0.8
1
1.2