tasks a-s

Task/Nth-root/XPL0/nth-root.xpl0

@@ -0,0 +1,21 @@
+include c:\cxpl\stdlib;
+
+func real NRoot(A, N);  \Return the Nth root of A
+real A, N;
+real X, X0, Y;
+int  I;
+[X:= 1.0;               \initial guess
+repeat  X0:= X;
+        Y:= 1.0;
+        for I:= 1 to fix(N)-1 do Y:= Y*X0;
+        X:= ((N-1.0)*X0 + A/Y) / N;
+until   abs(X-X0) < 1.0E-15;            \(until X=X0 doesn't always work)
+return X;
+];
+
+[Format(5, 15);
+RlOut(0, NRoot( 2., 2.));  CrLf(0);
+RlOut(0, Power( 2., 0.5)); CrLf(0);     \for comparison
+RlOut(0, NRoot(27., 3.));  CrLf(0);
+RlOut(0, NRoot(1024.,10.)); CrLf(0);
+]