Calculate the label angle

Get the angle from the end points of the segment. The angles makes the segment labels perpendicular to the circle. An angle of 0 is the positive x-axis so the angle adjustment is directly the correction for ggplot. A correction is applied to make the labels on the left side of the plot more readable.

Usage

calculate_angle(box_max, box_min)

Arguments

box_max

A numeric vector of upper endpoints of segments as a proportion.

box_min

A numeric vector of lower endpoints of segments as a proportion.

Value

The angle correction as should be given to ggplot.