# 4*atan(x)
# x	y1
-20.0	-6.083351724291815
-19.0	-6.072853060735819
-18.0	-6.061191286196719
-17.0	-6.048162016316696
-16.0	-6.033510067195757
-15.0	-6.016912652076291
-14.0	-5.997955448038425
-13.0	-5.976097742100475
-12.0	-5.950620379625821
-11.0	-5.920545758376606
-10.0	-5.884510697214939
-9.0	-5.840556422484004
-8.0	-5.78576532899254
-7.0	-5.715597088762931
-6.0	-5.6225905975210795
-5.0	-5.493603067780064
-4.0	-5.30327065467213
-3.0	-4.996183089593018
-2.0	-4.428594871176362
-1.0	-3.141592653589793
0.0	0.0
1.0	3.141592653589793
2.0	4.428594871176362
3.0	4.996183089593018
4.0	5.30327065467213
5.0000000000000036	5.493603067780064
6.0	5.6225905975210795
7.0	5.715597088762931
8.0	5.78576532899254
9.0	5.840556422484004
10.0	5.884510697214939
10.999999999999996	5.920545758376606
12.0	5.950620379625821
13.0	5.976097742100475
14.0	5.997955448038425
15.0	6.016912652076291
16.0	6.033510067195757
17.0	6.048162016316696
18.0	6.061191286196719
19.0	6.072853060735819