CALL INV Routine

Calculates a matrix that is the inverse of the provided input matrix that should be a square, non-singular matrix.

Category:	Matrix Operations
Requirement:	Both the input and output matrices must be square and have the same dimensions.

Syntax

Example

Syntax

CALL INV(X, Y);

Required Arguments

X: specifies an input matrix with dimensions m x m (that is, X[m, m]).

Y: specifies an output matrix with dimensions m x m (that is, Y[m, m]), such that

where ' denotes inverse

and I is the identity matrix.

Example

The following example uses the INV CALL routine:

options pageno=1 nodate;

proc fcmp;
   array mat1[3,3] (0.3, -0.78, -0.82, 0.54, 1.74,
                    1.2, -1.3, 0.25, 1.49);
   array result[3,3];
   call inv(mat1, result);
   put result=;
quit;

Output from the INV CALL Routine

                                The SAS System                               1

                              The FCMP Procedure

result[1, 1]=4.0460407887 result[1, 2]=1.6892917399 result[1, 3]=0.8661767509
result[2, 1]=-4.173108283 result[2, 2]=-1.092427483 result[2, 3]=-1.416802558
result[3, 1]=4.230288655 result[3, 2]=1.6571719011 result[3, 3]=1.6645841716