Calling Functions in the R Language

Read the data. The following statements read the Weight and Height variables from the Sashelp.Class data set into SAS/IML vectors with the same names:

proc iml;
use Sashelp.Class;
read all var {Weight Height};
close Sashelp.Class;

Transfer the data to R. The following statements run the ExportMatrixToR subroutine in order to transfer data from a SAS/IML matrix into an R matrix. The names of the corresponding R vectors that contain the data are w and h.

/* send matrices to R */
call ExportMatrixToR(Weight, "w");
call ExportMatrixToR(Height, "h");

Call R functions to perform some analysis. The SUBMIT statement with the R option is used to send statements to R. Comments in R begin with a hash mark (#, also called a number sign or a pound sign).

submit / R;
   Model    <- lm(w ~ h, na.action="na.exclude")         # a
   ParamEst <- coef(Model)                               # b
   Pred     <- fitted(Model)
   Resid    <- residuals(Model)
endsubmit;

The R program consists of the following steps:

Transfer the data from R. The ImportMatrixFromR subroutine transfers the ParamEst vector from R into a SAS/IML vector named pe. This vector is printed by the SAS/IML PRINT statement. The predicted values (Pred) and residual values (Resid) can be transferred similarly. The parameter estimates are used to compute the predicted values for a series of hypothetical heights, as shown in Figure 12.3.

call ImportMatrixFromR(pe, "ParamEst");
print pe[r={"Intercept" "Height"}];

ht = T( do(55, 70, 5) );
A = j(nrow(ht),1,1) || ht;
pred_wt = A * pe;
print ht pred_wt;