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POPossible Code Speed Optimisations?
 

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    <p>Ok so I have a my Trig class that I use to store a static table of values for faster execution of sin, cos, and tan functions in my program. Are there any comments and/or speed improvements that could be made over my current method? Thanks to previous answers, I am already feeling much more competent with C++.</p> <p>Trig.h</p> <pre><code>#pragma once #include &lt;math.h&gt; class Trig { private: struct Table { static const int multiple = 10; // Accurately stores values to 1/10 of a degree double sin[360*multiple]; Table(); }; static const Table table; static void shrinkRange(double*); // Shrinks degrees to range 0-359 for proper array indexing public: static double sin(double); static double cos(double); static double tan(double); }; </code></pre> <p>Trig.cpp</p> <pre><code>#include "Trig.h" Trig::Table::Table() // table constructor { double const PI = 3.14159265358979323; double const degToRad = PI/180.0; double const incr = 1.0/multiple; int index = 0; for (double angle = 0; index != 360*table.multiple; angle += incr) Table::sin[index++] = _INC_MATH::sin(angle*degToRad); } Trig::Table const Trig::table; // initialize static table member void Trig::shrinkRange(double* degrees) { if (*degrees &gt;= 360) *degrees -= 360*( (int)*degrees/360); if (*degrees &lt; 0) *degrees += 360*( -(int)*degrees/360 + 1); } double Trig::sin(double degrees) { shrinkRange(&amp;degrees); degrees *= table.multiple; return Trig::table.sin[(int)(degrees+0.5)]; } double Trig::cos(double degrees) { return Trig::sin(degrees + 90); } double Trig::tan(double degrees) { return Trig::sin(degrees)/Trig::cos(degrees); } </code></pre>
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    1. COThis isn't Java. It's `Trig::createTable`.
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      1. POPossible Code Speed Optimisations?
      1. USLuchian Grigore
    2. COThis is basic C++ syntax. I recommend getting [a good book](http://stackoverflow.com/questions/388242/the-definitive-c-book-guide-and-list). (try `Trig::createTable()`)
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      1. USR. Martinho Fernandes
    3. COThere's no point in editing an existing closed off-topic question to the extent that it bears no relation to the original question in terms of topic, etc. As such, you probably want to ask a new question.
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      1. USJohn Parker
 

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