Calling Functions in the R Language |

In order to call R from the SAS system, the R statistical software must be installed on the SAS workspace server and the RLANG system option must be enabled. (See The RLANG System Option.)

Chapter 10, Submitting SAS Statements, describes how to submit SAS statements from PROC IML. Submitting R statements is similar. You use a SUBMIT statement, but add the R option: SUBMIT / R. All statements in the program between the SUBMIT statement and the next ENDSUBMIT statement are sent to R for execution. The ENDSUBMIT statement must appear on a line by itself.

The simplest program that calls R is one that does not transfer any data between the two environments. In the following program, SAS/IML is used to compute the product of a matrix and a vector. The result is printed. Then the SUBMIT statement with the R option is used to send an equivalent set of statements to R.

proc iml; /* Comparison of matrix operations in IML and R */ print "---------- SAS/IML Results -----------------"; x = 1:3; /* vector of sequence 1,2,3 */ m = {1 2 3, 4 5 6, 7 8 9}; /* 3 x 3 matrix */ q = m * t(x); /* matrix multiplication */ print q;

print "------------- R Results --------------------"; submit / R; rx <- matrix( 1:3, nrow=1) # vector of sequence 1,2,3 rm <- matrix( 1:9, nrow=3, byrow=TRUE) # 3 x 3 matrix rq <- rm %*% t(rx) # matrix multiplication print(rq) endsubmit;

The printed output from R is automatically routed to the SAS/IML Studio output window, as shown in Figure 11.1. As expected, the result of the computation is the same in R as in SAS/IML.

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