Return angle between Distance tool and horizontal axis
getAngleFromHorizontal is not recommended. Use one of the ROI
classes instead, described in ROI Creation Overview.
Angle, returned as a numeric scalar in the range [0, 180] degrees.
To understand how
imdistline calculates the angle returned by
getAngleToHorizontal, draw an imaginary horizontal vector from
the bottom endpoint of the distance line, extending to the right. The value returned by
getAngleToHorizontal is the angle from this horizontal vector to
the distance line, which can range from 0 to 180 degrees.