Figure 3From: Exploratory disease mapping: kriging the spatial risk function from regional count dataEmpirical semivariogram from smoothed SIDS mortality rates and fitted exponential model. Exponential model (sill = 0.22, range = 0.37) fitted by weighted least squares (WLSE) to the robust empirical semivariogram from empirical Bayesian smoothed annual SIDS mortality rates per 1000 live births from 100 counties of North Carolina, 1974–1984.Back to article page