1 files changed, 40 insertions, 0 deletions
diff --git a/Tests/Tutorial/Step5/MathFunctions/mysqrt.cxx b/Tests/Tutorial/Step5/MathFunctions/mysqrt.cxx
new file mode 100644
index 0000000..458ed63
--- /dev/null
+++ b/Tests/Tutorial/Step5/MathFunctions/mysqrt.cxx
@@ -0,0 +1,40 @@
+#include "MathFunctions.h"
+#include "TutorialConfig.h"
+#include <stdio.h>
+
+// include the generated table
+#include "Table.h"
+
+#include <math.h>
+
+// a hack square root calculation using simple operations
+double mysqrt(double x)
+{
+  if (x <= 0) {
+    return 0;
+  }
+
+  double result;
+
+  // if we have both log and exp then use them
+  double delta;
+
+  // use the table to help find an initial value
+  result = x;
+  if (x >= 1 && x < 10) {
+    result = sqrtTable[static_cast<int>(x)];
+  }
+
+  // do ten iterations
+  int i;
+  for (i = 0; i < 10; ++i) {
+    if (result <= 0) {
+      result = 0.1;
+    }
+    delta = x - (result * result);
+    result = result + 0.5 * delta / result;
+    fprintf(stdout, "Computing sqrt of %g to be %g\n", x, result);
+  }
+
+  return result;
+}