what is the nearest neighbour define mat crossvalidation what is a mat model what is nn crossvalidation what is nan model cost of model error what is mat what is the nn model of the nearest neighbour? what is the sst model what model is best to use for the closest nearest neighbours why is it important to use $k$ for a simulation what is the best model to estimate sst what is sql mat which method to use when predicting sst? what is mat what is the spatial accuracy of sst what is the purpose of a mat what is the spatial auto correlation of the training data? rmsep cost of rmsp estimate what is rmsep