If you care about your money, use Math::BigFloat, as dragonchild suggested.
As others have said, the problem is that floating point binary can't represent most decimal fractions exactly. It's analogous to the way that 1/3 is a repeating decimal (0.3333...). 0.95 and 0.9 are both repeating binary numbers. As can you see, it goes both ways: even 1/3 in trinary notation does not repeat: 0.1.
The solution is to use "fixed point" or "arbitrary precision" decimal arithmetic. This is usally implemented internally as an integer (or byte array) with a scale. I'm not sure how Math::BigFloat does its job, but it is the standard module for arbitrary precision arithmetic in Perl.
-
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.
|