acos_d: Compute inverse cosine with angle given in degrees
Description
Provides the functionality of acos, but for input angles measured in degrees (not radians).
Usage
acos_d(theta = 0)
Value
Returns a numeric value for the inverse cosine of the specified angular measurement
Arguments
theta
A numeric angular measurement in degrees from north.
Author
Tarmo K. Remmel
Details
Since the R default is to compute trigonometric functions on angular measurements stored in radians, this simple function performs the conversion from degrees, reducing the need to do so a priori, outside the function.