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atan2

atan2(y, x)

Compute the inverse tangent of y/x, using the signs of both x and y to determine the quadrant of the return value.

Examples

1. Compute the inverse tangent of a single value:

   julia> atan2(1, 1)
   0.7853981633974483

   This example computes the inverse tangent of 1/1, which corresponds to an angle of approximately 0.785 radians.

2. Compute the inverse tangent for multiple values:

   julia> x = [1, -1, 0];
   julia> y = [1, 1, -1];
   julia> atan2.(y, x)
   3-element Array{Float64,1}:
   0.7853981633974483
   2.356194490192345
   -1.5707963267948966

   Here, the atan2 function is applied element-wise to compute the inverse tangent for each corresponding pair of x and y values.

3. Handle division by zero:

   julia> atan2(0, 5)
   0.0

   When y is zero and x is non-zero, the result is always zero.

Common mistake example:

julia> atan2(5, 0)
ERROR: DomainError with atan2: angle is undefined for complex result

In this example, x is zero and y is non-zero, resulting in a domain error. It's important to avoid division by zero when using atan2 to prevent such errors.

See Also

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