Examples

1. Computation of tan^-1(∝) = π/2

This equation is realized as:

To convert radians to degrees, the angle in radians is multiplied by (180/π) = 57.2958.

Since the atan2 block uses the value of x₁, the signs of x₁ and x₂, and the ratio x₁/x₂ in computing the inverse tangent, the result depends on all these parameters. In the current case, since the ratio is infinity, atan2 computes the inverse correctly to be π/2 radians, or 90^o. Also, in the current case, x₁ can be any positive value, since its ratio with 0 will be infinity, regardless of its value.

2. Computation of tan^-1(-1): quadrant dependency

Using the same configuration in the above example, tan^-1(-1) is realized as:

Here, the angle obtained is -0.7854 radians, or -45^o, because the atan2 block determines that the angle lies in the fourth quadrant. However, it is immediately apparent that the same ratio of -1 can be obtained by flipping the signs on x₁ and x₂:

In this case, the atan2 block uses the relative signs of x₁ and x₂ to determine that the angle lies in the second quadrant, and yields an angle of 180 - 45 = 135^o, or 2.356 radians.