SIMSCRIPT II.5 Programming Language

Programming Language Concepts
2.27.3 A Matrix Multiplication Program
Two matrices (double-subscripted variables) are to be read from data records. Matrix A is input row
by row. That is, the values appear in the order A(1,1), A(1,2), ..., A(1,M), A(2,1),
..., A(2,M), A(3,1), ..., A(N,M). Matrix B appears column by column in the order
B(1,1), B(2,1) ..., B(S,1), B(1,2), ..., B(S,2), B(1,3), ..., B(R,S).
The values of the matrix dimensions N, M, R, and S precede the element data. This program reads
the data, checks that multiplication is possible and, if so, multiplies the matrices A and B together
placing the values in matrix C.
For matrix multiplication to be possible, M must equal R. The rules for computation are:
if A has dimensions N, M and
B has dimensions M, S then
C has dimensions N, S and the elements of C are computed as:
M
C(I,K) = Σ A(I,J) * B(J,K)
j = 1
The program below illustrates the use of the reserve statement with variable dimensions executed
in the body of a program, two forms of read statement formats for inputting subscripted variables,
nested for loops, and the use of the list statement.
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