For my machine, it will give the wrong answer for any time $yearlyamount equals k * 13, for k at least 9. This is because 52 is 4 * 13, and hence the division by 52 gives the exact answer, and subtracting 0.005 (which cannot be represented exactly in binary) from it causes %f to round it down to the next decimal. For instance, 117 / 52 - 0.005, on my computer with my Perl (5.8.6, with longdoubles and 64bitints) is about 2.244999999999999999895916591441391574335284531116485595703125.
Just a tiny, tiny bit below 2.245, but that's enough to give the answer 2.24, instead of 2.25.
Doing arithmetic with reals is very tricky, and it's therefore better to use a good module. POSIX.pm for instance, with its floor method.
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|