June 2018 Update

Task/Matrix-exponentiation-operator/Sidef/matrix-exponentiation-operator.sidef

@@ -0,0 +1,22 @@
+class Array {
+    method ** (Number n { .>= 0 }) {
+        var tmp = self
+        var out = self.len.of {|i| self.len.of {|j| i == j ? 1 : 0 }}
+        loop {
+            out = (out `mmul` tmp) if n.is_odd
+            n >>= 1 || break
+            tmp = (tmp `mmul` tmp)
+        }
+        return out
+    }
+}
+
+var m = [[1, 2, 0],
+         [0, 3, 1],
+         [1, 0, 0]]
+
+for order in (0..5) {
+    say "### Order #{order}"
+    var t = (m ** order)
+    say ('  ', t.join("\n  "))
+}

Task/Matrix-exponentiation-operator/Stata/matrix-exponentiation-operator-1.stata

@@ -0,0 +1,13 @@
+real matrix matpow(real matrix a, real scalar n) {
+	real matrix p, x
+	real scalar i, s
+	s = n<0
+	n = abs(n)
+	x = a
+	p = I(rows(a))
+	for (i=n; i>0; i=floor(i/2)) {
+		if (mod(i,2)==1) p = p*x
+		x = x*x
+	}
+	return(s?luinv(p):p)
+}

Task/Matrix-exponentiation-operator/Stata/matrix-exponentiation-operator-2.stata

@@ -0,0 +1,7 @@
+: matpow((0,1\1,1),10)
+[symmetric]
+        1    2
+    +-----------+
+  1 |  34       |
+  2 |  55   89  |
+    +-----------+