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Determinant and permanent: Difference between revisions
added Ol
m (Maknongan moved page Matrix arithmetic to Determinant and permanent: "Matrix arithmetic" would generally refer to something other than determinants (e.g., matrix products, sums, scalar multiplication, polynomials).) |
(added Ol) |
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perm: 29556.0 det: 0.0
perm: 6778800.0 det: 0.0</pre>
=={{header|Ol}}==
<lang scheme>
; helper function that returns rest of matrix by col/row
(define (rest matrix i j)
(define (exclude1 l x) (append (take l (- x 1)) (drop l x)))
(exclude1
(map exclude1
matrix (repeat i (length matrix)))
j))
; det calculator
(define (det matrix)
(let loop ((n (length matrix)) (matrix matrix))
(if (eq? n 1)
(caar matrix)
(fold (lambda (x a j)
(+ x (* a (lref '(-1 1) (mod j 2)) (det (rest matrix j 1)))))
0
(car matrix)
(iota n 1)))))
; ---=( testing )=---------------------
(print (det '(
(1 2)
(3 4)))
; ==> -2
(print (det '(
( 1 2 3 1)
(-1 -1 -1 2)
( 1 3 1 1)
(-2 -2 0 -1)))
; ==> 26
(print (det '(
( 0 1 2 3 4)
( 5 6 7 8 9)
(10 11 12 13 14)
(15 16 17 18 19)
(20 21 22 23 24)))
; ==> 0
</lang>
=={{header|PARI/GP}}==
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