Compute the empirical semivariogram for a data set with specified x and y spatial coordinates and residuals.
sv(data, xcoordcol, ycoordcol, residcol, bins = 15, cutoff = NULL, ...)A data frame or tibble that contains variables for the x coordinates, y coordinates, and residuals.
is the name of the column in the data frame with x coordinates or longitudinal coordinates
is the name of the column in the data frame with y coordinates or latitudinal coordinates
is the name of the column in the data frame with residuals.
Number of equally spaced semivariogram bins. The default is 15.
The maximum spatial distance to be considered. The default is half of the maximum observed distance in the data frame.
Additional arguments to be used by stats::dist() for
spatial distance calculations.
A data frame with the average distance in each bin (dist), the semivariance (gamma), and the number of unique pairs in each bin (np)
data(exampledataset) ## load a toy data set
slmobj <- slmfit(formula = counts ~ pred1 + pred2, data = exampledataset,
xcoordcol = 'xcoords', ycoordcol = 'ycoords', areacol = 'areavar')
sampleddataset <- na.omit(exampledataset)
svexample <- data.frame(
xcoords = sampleddataset$xcoords,
ycoords = sampleddataset$ycoords,
resids = residuals(slmobj)
)
svdata <- sv(svexample, "xcoords", "ycoords", "resids")