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author | Anas Nashif <anas.nashif@intel.com> | 2012-10-30 15:39:57 -0700 |
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committer | Anas Nashif <anas.nashif@intel.com> | 2012-10-30 15:39:57 -0700 |
commit | 035c7fabc3b82cbc9a346c11abe2e9462b4c0379 (patch) | |
tree | 7e40f5a790eae329a8c5d3e59f046451767956ff /Tests/Tutorial/Step4/MathFunctions/mysqrt.cxx | |
download | cmake-035c7fabc3b82cbc9a346c11abe2e9462b4c0379.tar.gz cmake-035c7fabc3b82cbc9a346c11abe2e9462b4c0379.tar.bz2 cmake-035c7fabc3b82cbc9a346c11abe2e9462b4c0379.zip |
Imported Upstream version 2.8.9upstream/2.8.9
Diffstat (limited to 'Tests/Tutorial/Step4/MathFunctions/mysqrt.cxx')
-rw-r--r-- | Tests/Tutorial/Step4/MathFunctions/mysqrt.cxx | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/Tests/Tutorial/Step4/MathFunctions/mysqrt.cxx b/Tests/Tutorial/Step4/MathFunctions/mysqrt.cxx new file mode 100644 index 000000000..0cf7db480 --- /dev/null +++ b/Tests/Tutorial/Step4/MathFunctions/mysqrt.cxx @@ -0,0 +1,39 @@ +#include <stdio.h> +#include "MathFunctions.h" +#include "TutorialConfig.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 +#if defined(HAVE_LOG) && defined (HAVE_EXP) + result = exp(log(x)*0.5); + fprintf(stdout,"Computing sqrt of %g to be %g using log\n",x,result); +#else + double delta; + result = 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); + } +#endif + return result; +} |