| n | the number of observations | 
| fitted | surface evaluated at the observed values of the predictors. | 
| residuals | response minus fitted values. | 
| enp | the equivalent number of parameters used in the model. | 
| s | the residual standard error for the model. | 
| one.delta | a numeric value used in prediction. | 
| two.delta | a numeric value used in prediction. | 
| trace.hat | an approximation of the trace of the hat matrix. | 
| divisor | a vector of values used to normalize the predictors. | 
| robust | the vector of robust weights | 
| pars | a list of the parameters used in the fitting. | 
| kd | a list containing information about the kd tree used in the fitting. Used for predictions. | 
| call | an image of the call that produced the object, but with the arguments all named and with the actual formula included as the formula argument. | 
| terms | an object of mode expression and class term summarizing the formula. Used by various methods, but typically not of direct relevance to users. | 
| xnames | the names of the predictors. | 
| x | the matrix of predictors. | 
| y | the response variable. | 
| weights | the weights used in the fit. | 
| model | the model frame for the model. This is only included if model = TRUE was set in the call. |