Time for an 2014 update…

Task/Matrix-arithmetic/D/matrix-arithmetic.d

@@ -1,7 +1,7 @@
 import std.algorithm, std.range, std.traits, permutations2,
        permutations_by_swapping1;
 
-auto prod(Range)(/*in*/ Range r) /*pure nothrow*/ {
+auto prod(Range)(Range r) /*pure*/ nothrow {
     return reduce!q{a * b}(cast(ForeachType!Range)1, r);
 }
 

Task/Matrix-arithmetic/Go/matrix-arithmetic.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+    "fmt"
+    "permute"
+)
+
+func determinant(m [][]float64) (d float64) {
+    p := make([]int, len(m))
+    for i := range p {
+        p[i] = i
+    }
+    it := permute.Iter(p)
+    for s := it(); s != 0; s = it() {
+        pr := 1.
+        for i, σ := range p {
+            pr *= m[i][σ]
+        }
+        d += float64(s) * pr
+    }
+    return
+}
+
+func permanent(m [][]float64) (d float64) {
+    p := make([]int, len(m))
+    for i := range p {
+        p[i] = i
+    }
+    it := permute.Iter(p)
+    for s := it(); s != 0; s = it() {
+        pr := 1.
+        for i, σ := range p {
+            pr *= m[i][σ]
+        }
+        d += pr
+    }
+    return
+}
+
+var m2 = [][]float64{
+    {1, 2},
+    {3, 4}}
+
+var m3 = [][]float64{
+    {2, 9, 4},
+    {7, 5, 3},
+    {6, 1, 8}}
+
+func main() {
+    fmt.Println(determinant(m2), permanent(m2))
+    fmt.Println(determinant(m3), permanent(m3))
+}

Task/Matrix-arithmetic/Julia/matrix-arithmetic-1.julia

@@ -0,0 +1 @@
+det(A)

Task/Matrix-arithmetic/Julia/matrix-arithmetic-2.julia

@@ -0,0 +1,5 @@
+function perm(A)
+  m, n = size(A)
+  if m != n; throw(ArgumentError("permanent is for square matrices only")); end
+  sum(σ -> prod(i -> A[i,σ[i]], 1:n), permutations(1:n))
+end

Task/Matrix-arithmetic/Julia/matrix-arithmetic-3.julia

@@ -0,0 +1,3 @@
+julia> A = [2 9 4; 7 5 3; 6 1 8]
+julia> det(A), perm(A)
+(-360.0,900)