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author | Brad King <brad.king@kitware.com> | 2020-01-14 14:06:26 (GMT) |
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committer | Kitware Robot <kwrobot@kitware.com> | 2020-01-14 14:06:40 (GMT) |
commit | 710371ca2f5032462e8dc352da869834bb421261 (patch) | |
tree | 10aaf87b7b2cedfc27a80ee0f55aa5aa9bea3071 /Help/guide/tutorial/Step12/MathFunctions/mysqrt.cxx | |
parent | a2a91eb1416a5a48b7ba55973f3805998d0a643a (diff) | |
parent | a7d25358a0ad1a9d8c80413dd620e773363e1b76 (diff) | |
download | CMake-710371ca2f5032462e8dc352da869834bb421261.zip CMake-710371ca2f5032462e8dc352da869834bb421261.tar.gz CMake-710371ca2f5032462e8dc352da869834bb421261.tar.bz2 |
Merge topic 'tutorial'
a7d25358a0 Tutorial: Add the PRIVATE keyword to target_link_libraries command
cf2afb1065 Tutorial: Remove 'Consumer' example
77b515f3eb Tutorial: Improve "MultiPackage" example
3a510a47b0 Tutorial: Add links to relevant CMake documentation
Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !4113
Diffstat (limited to 'Help/guide/tutorial/Step12/MathFunctions/mysqrt.cxx')
-rw-r--r-- | Help/guide/tutorial/Step12/MathFunctions/mysqrt.cxx | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/Help/guide/tutorial/Step12/MathFunctions/mysqrt.cxx b/Help/guide/tutorial/Step12/MathFunctions/mysqrt.cxx new file mode 100644 index 0000000..8153f18 --- /dev/null +++ b/Help/guide/tutorial/Step12/MathFunctions/mysqrt.cxx @@ -0,0 +1,37 @@ +#include <iostream> + +#include "MathFunctions.h" + +// include the generated table +#include "Table.h" + +namespace mathfunctions { +namespace detail { +// a hack square root calculation using simple operations +double mysqrt(double x) +{ + if (x <= 0) { + return 0; + } + + // 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)]; + } + + // 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; +} +} +} |