A-M baby

Task/Matrix-exponentiation-operator/Tcl/matrix-exponentiation-operator.tcl

@@ -0,0 +1,24 @@
+package require Tcl 8.5
+namespace path {::tcl::mathop ::tcl::mathfunc}
+
+proc matrix_exp {m pow} {
+    if { ! [string is int -strict $pow]} {
+        error "non-integer exponents not implemented"
+    }
+    if {$pow < 0} {
+        error "negative exponents not implemented"
+    }
+    lassign [size $m] rows cols
+    # assume square matrix
+    set temp [identity $rows]
+    for {set n 1} {$n <= $pow} {incr n} {
+        set temp [matrix_multiply $temp $m]
+    }
+    return $temp
+}
+
+proc identity {size} {
+    set i [lrepeat $size [lrepeat $size 0]]
+    for {set n 0} {$n < $size} {incr n} {lset i $n $n 1}
+    return $i
+}