doc/documentation.html

<!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8">
        <title>quadrillionth-decimal-place User Documentation</title>
    </head>
    <body>

        <h1>Compilation</h1>

        <p>
        To compile my project, you need to first install the 
        <a href="http://gmplib.org/">GNU MP Bignum Library (GNU GMP)</a>.  On the CS50 Appliance,
        that is quite easy.  Simply type the following in the Terminal:
        <pre>
    sudo yum install gmp-devel</pre>
        <p>
        You also need to install Check:
        </p>
        <pre>
    sudo yum install check-devel</pre>
        <p>After GNU GMP is installed, simply type <i>make</i> in the Terminal in the project's 
        top-level directory (the one containing the Makefile).
        </p>
        
        <h1>Configuration</h1>

        <p>Other than installing GNU GMP, which you've already done, no special configuration is needed.</p>

        <h1>Use</h1>

        <p>Here is the usage string for my project:</p>
        <pre>
    project [-t] [-n number_code] d</pre>
        <p>
            <i>d</i> is the only required argument.  This specifies the position of the first digit to the right
            of the decimal place that you want to compute.
        </p>
        <p>
            <i>number_code</i> is an optional argument and has two valid values:
        </p>
            <ul>
                <li><i>pi</i> for computing hexadecimal digits of pi.</li>
                <li><i>log2</i> for computing binary digits of log(2).</li>
            </ul>
        <p>
            The default value for <i>number_code</i> is <i>pi</i>.
        </p>
        <p>
            <i>t</i> is an optional flag.  If set, the program reports how long the computation took.
        </p>
        <h2>Examples</h2>
        <p>Let's compute the millionth hexadecimal digit of pi:</p>
        <pre>
    jharvard@appliance (~/Dropbox/project/quadrillionth-decimal-place): ./project -n pi 1000000
    Hex digits of pi beginning at position 1000000: 26C65E52</pre>
        
        <p>
        Since the default value of <i>n</i> is <i>pi</i>, there is a shorter, equivalent invocation:
        </p>
        <pre>
    jharvard@appliance (~/Dropbox/project/quadrillionth-decimal-place): ./project 1000000
    Hex digits of pi beginning at position 1000000: 26C65E52</pre>
        <p>Now, using the <i>t</i> flag, let's see how long it takes our program to compute the 
        millionth digit of pi:
        </p>
        <pre>
    jharvard@appliance (~/Dropbox/project/quadrillionth-decimal-place): ./project -t 1000000
    Hex digits of pi beginning at position 1000000: 26C65E52
        Time to compute = 00:00:11.</pre>
        <p>
            11 seconds!  Pretty darn fast!!
        </p>
        <p>
        Finally, let's compute the millionth binary digit of log(2):
        </p>
        <pre>
    jharvard@appliance (~/Dropbox/project/quadrillionth-decimal-place): ./project -t -n log2 1000000
    Binary digits of log(2) beginning at position 1000000: 11010100
        Time to compute = 00:00:02.</pre>

    </body>
</html>