predict.stratafit function

Perform Finite Population Block Kriging

Uses an object of class stratafit from the stratafit()

function to predict the response on the unsampled sites for separate strata. The column of the data set that has the response should have numeric values for the observed response on the sampled sites and NA for any site that was not sampled. Note that there is no newdata argument to predict.stratafit(): any point in space for which a prediction is needed should be included in the original data set in stratafit()

with the response variable as NA.

## S3 method for class 'stratafit'
predict(object, wtscol = NULL, conf_level = 0.9, ...)

Arguments

• object: is an object generated from stratafit()
• wtscol: is the name of the column that contains the weights for prediction. The default setting predicts the population total
• conf_level,: by default, 0.90, this is the desired confidence level for a prediction interval
• ...: further arguments passed to or from other methods.

Returns

a list with

• the estimated population total

• the estimated prediction variance

• a data frame containing

  1. x-coordinates
  2. y-coordinates
  3. density predictions
  4. count predictions
  5. site-by-site density prediction variances
  6. site-by-site count prediction variances
  7. indicator variable for whether or not the each site was sampled
  8. estimated mean for each site
  9. area of each site

• vector with estimated covariance parameters

• the formula used to fit the model in slmfit()

Examples

data(exampledataset) ## load a toy data set
exampledataset$strata <- c(rep("A", 19), rep("B", 21))
strataobj <- stratafit(formula = counts ~ pred1 + pred2,
 data = exampledataset, stratacol = "strata",
xcoordcol = 'xcoords', ycoordcol = 'ycoords', areacol = 'areavar')
predict(strataobj)