##### dart:math library

1. Classes
2. MutableRectangle
3. Point
4. Random
5. Rectangle
6. Constants
7. e
8. ln2
9. ln10
10. log2e
11. log10e
12. pi
13. sqrt1_2
14. sqrt2
15. Functions
16. acos
17. asin
18. atan
19. atan2
20. cos
21. exp
22. log
23. max
24. min
25. pow
26. sin
27. sqrt
28. tan

# atan function

double atan (num x)

Converts `x` to a double and returns its arc tangent in radians.

Returns a value in the range -PI/2..PI/2, or NaN if `x` is NaN.

## Implementation

    external double atan(num x);