RosettaCodeData/Task/Matrix-multiplication/REXX/matrix-multiplication.rexx
2023-07-01 13:44:08 -04:00

82 lines
2.7 KiB
Rexx

/*REXX program calculates the Kronecker product of two arbitrary size matrices. */
Signal On syntax
x.=0
amat=4X2 1 2 3 4 5 6 7 8 /* define A matrix size and elements */
bmat=2X3 1 2 3 4 5 6 /* " B " " " " */
Call makeMat 'A',amat /* construct A matrix from elements */
Call makeMat 'B',bmat /* " B " " " */
If cols.A<>rows.B Then
Call exit 'Matrices are incompatible for matrix multiplication',
'cols.A='cols.A'<>rows.B='rows.B
Call multMat /* multiply A x B */
Call showMat 'A',amat /* display matrix A */
Call showMat 'B',bmat /* " " B */
Call showMat 'C',mm /* " " C */
Exit
/*--------------------------------------------------------------------*/
makeMat:
Parse Arg what,size elements /*elements: e.1.1 e.1.2 - e.rows cols*/
Parse Var size rows 'X' cols
x.what.shape=rows cols
Parse Value rows cols With rows.what cols.what
n=0
Do r=1 To rows
Do c=1 To cols
n=n+1
element=word(elements,n)
x.what.r.c=element
End
End
Return
/*--------------------------------------------------------------------*/
multMat:
/* x.C.*.* = x.A.*.* x x.B.*.* */
Do i=1 To rows.A
Do j=1 To cols.B
Do k=1 To cols.A
x.C.i.j=x.C.i.j+x.A.i.k*x.B.k.j
End /*k*/
End /*j*/
End /*i*/
mm=rows.A||'X'||cols.B
Do i=1 To rows.A
Do j=1 To cols.B
mm=mm x.C.i.j
End /*j*/
End /*i*/
Call makeMat 'C',mm
Return
/*--------------------------------------------------------------------*/
showMat:
Parse Arg what,size .
Parse Var size rows 'X' cols
z='+'
b6=left('',6)
Say ''
Say b6 copies('-',7) 'matrix' what copies('-',7)
w=0
Do r=1 To rows
Do c=1 To cols
w=max(w,length(x.what.r.c))
End
End
Say b6 b6 '+'copies('-',cols*(w+1)+1)'+' /* top border */
Do r=1 To rows
line='|' right(x.what.r.1,w) /* element of first colsumn */ /* start with long vertical bar */
Do c=2 To cols /* loop for other columns */
line=line right(x.what.r.c,w) /* append the elements */
End /* c */
Say b6 b6 line '|' /* append a long vertical bar. */
End /* r */
Say b6 b6 '+'copies('-',cols*(w+1)+1)'+' /* bottom border */
Return
exit:
Say arg(1)
Exit
Syntax:
Say 'Syntax raised in line' sigl
Say sourceline(sigl)
Say 'rc='rc '('errortext(rc)')'
Say '***** There was a problem!'
Exit