Data commit

Task/Nth-root/S-BASIC/nth-root-1.basic

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+rem - return nth root of x
+function nthroot(x, n = real) = real
+end = exp((1.0 / n) * log(x))
+
+rem - exercise the routine by finding successive roots of 144
+var i = integer
+
+print "Finding the nth root of x"
+print "  x      n         root"
+print "-----------------------"
+for i = 1 to 8
+   print using "###   ####    ###.####"; 144; i; nthroot(144, i)
+next i
+
+end

Task/Nth-root/S-BASIC/nth-root-2.basic

@@ -0,0 +1,23 @@
+rem - return the nth root of real.double value x to stated precision
+function nthroot(n, x, precision = real.double) = real.double
+   var x0, x1 = real.double
+   x0 = x
+   x1 = x / n   rem - initial guess
+   while abs(x1 - x0) > precision do
+      begin
+        x0 = x1
+        x1 = ((n-1.0) * x1 + x / x1 ^ (n-1.0)) / n
+      end
+end = x1
+
+rem -- exercise the routine
+
+var i = integer
+print "Finding the nth root of 144 to 6 decimal places"
+print "  x      n        root"
+print "------------------------"
+for i = 1 to 8
+   print using "###   ####    ###.######"; 144; i; nthroot(i, 144.0, 1E-7)
+next i
+
+end