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-rw-r--r--Help/guide/tutorial/Step5/MathFunctions/mysqrt.cxx23
1 files changed, 23 insertions, 0 deletions
diff --git a/Help/guide/tutorial/Step5/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step5/MathFunctions/mysqrt.cxx
new file mode 100644
index 0000000..7d9379e
--- /dev/null
+++ b/Help/guide/tutorial/Step5/MathFunctions/mysqrt.cxx
@@ -0,0 +1,23 @@
+#include "MathFunctions.h"
+#include <iostream>
+
+// a hack square root calculation using simple operations
+double mysqrt(double x)
+{
+ if (x <= 0) {
+ return 0;
+ }
+
+ double result = x;
+
+ // do ten iterations
+ for (int i = 0; i < 10; ++i) {
+ if (result <= 0) {
+ result = 0.1;
+ }
+ double delta = x - (result * result);
+ result = result + 0.5 * delta / result;
+ std::cout << "Computing sqrt of " << x << " to be " << result << std::endl;
+ }
+ return result;
+}