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author | Betsy McPhail <betsy.mcphail@kitware.com> | 2019-07-26 16:46:08 (GMT) |
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committer | Brad King <brad.king@kitware.com> | 2019-08-19 15:49:05 (GMT) |
commit | a36731c63460a41caae596b6dcbc75771a810549 (patch) | |
tree | 28c38e2c540d20eacbcf58cbadc5694c8cda82bf /Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx | |
parent | df9cdf629c5211282dcab2e4751f69032e25a244 (diff) | |
download | CMake-a36731c63460a41caae596b6dcbc75771a810549.zip CMake-a36731c63460a41caae596b6dcbc75771a810549.tar.gz CMake-a36731c63460a41caae596b6dcbc75771a810549.tar.bz2 |
Tutorial: Improve Step 6
* Print message when using the table
* Remove duplicated comment
* Remove HAVE_LOG and HAVE_EXP checks, use generated table instead
Diffstat (limited to 'Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx')
-rw-r--r-- | Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx | 13 |
1 files changed, 2 insertions, 11 deletions
diff --git a/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx index 2b1d889..2ae60c6 100644 --- a/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx +++ b/Help/guide/tutorial/Step8/MathFunctions/mysqrt.cxx @@ -4,8 +4,6 @@ // include the generated table #include "Table.h" -#include <cmath> - // a hack square root calculation using simple operations double mysqrt(double x) { @@ -13,20 +11,13 @@ double mysqrt(double x) return 0; } - // if we have both log and exp then use them -#if defined(HAVE_LOG) && defined(HAVE_EXP) - double result = exp(log(x) * 0.5); - std::cout << "Computing sqrt of " << x << " to be " << result - << " using log and exp" << std::endl; -#else // use the table to help find an initial value double result = x; if (x >= 1 && x < 10) { + std::cout << "Use the table to help find an initial value " << std::endl; result = sqrtTable[static_cast<int>(x)]; } - // if we have both log and exp then use them - // do ten iterations for (int i = 0; i < 10; ++i) { if (result <= 0) { @@ -36,6 +27,6 @@ double mysqrt(double x) result = result + 0.5 * delta / result; std::cout << "Computing sqrt of " << x << " to be " << result << std::endl; } -#endif + return result; } |