geodXyInverse: Inverse Geodesic Calculation
Description
The calculation is done by finding a minimum value of a cost
function that is the vector difference between (x,y)
and the corresponding values returned by geodXy. This
minimum is calculated in C for speed, using the nmmin function
that is the underpinning for the Nelder-Meade version of the R function
optim.
Usage
geodXyInverse(x, y, longitudeRef = 0, latitudeRef = 0)
Arguments
x
value of x in metres, as given by geodXy y
value of y in metres, as given by geodXy longitudeRef
reference longitude, as supplied to geodXy latitudeRef
reference latitude, as supplied to geodXy Value
a data frame containing longitude and latitude