Choice of method: "cubic" is currently the only allowed option, which fits a cubic function with linear extrapolation, on a log-log scale.
plot
Output a diagnostic plot.
outfile
If NULL, plot to current device. Otherwise, plot to the .pdf file outfile.
Value
An object of class chicagoData, with the parameters of the distance function present as params(cd)$distFunParams.
Details
By default, we look in 75 distance bins, and a cubic fit is used. For distances that lie outside of the bin boundaries, it is assumed that the function is log-linear, with continuity of f and its first derivative on the log-scale.