Determinant and permanent: Difference between revisions

=={{header|Arturo}}==

<lang rebol>printMatrix: function [m][

loop m 'row -> print map row 'val [pad to :string .format:".2f" val 6]

print "--------------------------------"

]

permutations: function [arr][

d: 1

c: array.of: size arr 0

xs: new arr

sign: 1

ret: new @[@[xs, sign]]

while [true][

while [d > 1][

d: d-1

c\[d]: 0

]

while [c\[d] >= d][

d: d+1

if d >= size arr -> return ret

]

i: (1 = and d 1)? -> c\[d] -> 0

tmp: xs\[i]

xs\[i]: xs\[d]

xs\[d]: tmp

sign: neg sign

'ret ++ @[new @[xs, sign]]

c\[d]: c\[d] + 1

]

return ret

]

perm: function [a][

n: 0..dec size a

result: new 0.0

loop permutate n 'sigma [

x: 1.0

loop n 'i -> x: x * get a\[i] sigma\[i]

'result + x

]

return result

]

det: function [a][

n: 0..dec size a

result: new 0.0

loop.with:'i permutations n 'p[

x: p\1

loop n 'i -> x: x * get a\[i] p\0\[i]

'result + x

]

return result

]

A: [[1.0 2.0]

[3.0 4.0]]

B: [[ 1.0 2 3 4]

[ 4.0 5 6 7]

[ 7.0 8 9 10]

[10.0 11 12 13]]

C: [[ 0.0 1 2 3 4]

[ 5.0 6 7 8 9]

[10.0 11 12 13 14]

[15.0 16 17 18 19]

[20.0 21 22 23 24]]

print ["A: perm ->" perm A "det ->" det A]

print ["B: perm ->" perm B "det ->" det B]

print ["C: perm ->" perm C "det ->" det C]</lang>

{{out}}

<pre>A: perm -> 10.0 det -> -2.0

B: perm -> 29556.0 det -> 0.0

C: perm -> 6778800.0 det -> 0.0</pre>