Difference between revisions of "Infinity (MathObject Class)"

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(Add headings and update answer checkers, properties, and methods)
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== The Infinity Class ==
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=== Infinity Class ===
   
The Infinity class handles the positive infinity of the extended reals. This value can be negated and used in intervals, but can be added to Reals (or other MathObjects) and can't be used as an argument to functions like <code>sin()</code> or <code>sqrt()</code>. In Perl code, you can use <code>Infinity</code> to obtain this value, or <code>-(Infinity)</code> to obtain its negation. E.g.,
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The Infinity class handles the positive infinity of the extended reals. This value can be negated and used in intervals, but can be added to Reals (or other MathObjects) and can't be used as an argument to functions like <code>sin()</code> or <code>sqrt()</code>. Infinity can be created in any Context, though <code>Numeric</code> context is commonly used.
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=== Creation ===
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In Perl code, you can use <code>Infinity</code> to obtain this value, or <code>-(Infinity)</code> to obtain its negation. E.g.,
   
 
Context("Numeric");
 
Context("Numeric");
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$Inf = Infinity;
 
$Inf = Infinity;
 
$MInf = -(Infinity);
 
$MInf = -(Infinity);
$I = Interval("(",0,Infinity,"]"); # easier as Interval("(0,infinity]");
 
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Context("Interval");
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$I = Interval("(",0,Infinity,"]"); # but easier as Interval("(0,infinity]");
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=== Answer Checker ===
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As with all MathObjects, you obtain an answer checker for an Infinity object via the <code>cmp()</code> method:
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ANS(Infinity->cmp);
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ANS((-(Infinity))->cmp);
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The Infinity class supports the [[Answer_Checker_Options_(MathObjects)| common answer-checker options]]. There are no additional options.
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=== Methods ===
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As with all MathObjects, the Infinity object supports the [[MathObject_Methods_and_Properties| common MathObject methods]]. There are no additional methods for this class.
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=== Properties ===
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As with all MathObjects, the Infinity object supports the [[MathObject_Methods_and_Properties| common MathObject properties]], and the following additional ones:
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{| class="wikitable"
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! Property !! Description
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|- style="vertical-align: baseline"
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| style="padding: 5px; white-space: nowrap" | <code>$r->{isNegative}</code>
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| style="padding: 5px" | True when the object represents <code>-Infinity</code>, false otherwise. You should not set this value yourself.
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|}
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<br>
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[[Category:MathObject_Classes]]
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[[Category:MathObjects]]
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<br>
 
<br>

Revision as of 12:22, 4 August 2012

Infinity Class

The Infinity class handles the positive infinity of the extended reals. This value can be negated and used in intervals, but can be added to Reals (or other MathObjects) and can't be used as an argument to functions like sin() or sqrt(). Infinity can be created in any Context, though Numeric context is commonly used.


Creation

In Perl code, you can use Infinity to obtain this value, or -(Infinity) to obtain its negation. E.g.,

   Context("Numeric");
   
   $Inf = Infinity;
   $MInf = -(Infinity);
   
   Context("Interval");
   $I = Interval("(",0,Infinity,"]");   # but easier as Interval("(0,infinity]");


Answer Checker

As with all MathObjects, you obtain an answer checker for an Infinity object via the cmp() method:

   ANS(Infinity->cmp);
   ANS((-(Infinity))->cmp);

The Infinity class supports the common answer-checker options. There are no additional options.


Methods

As with all MathObjects, the Infinity object supports the common MathObject methods. There are no additional methods for this class.


Properties

As with all MathObjects, the Infinity object supports the common MathObject properties, and the following additional ones:

Property Description
$r->{isNegative} True when the object represents -Infinity, false otherwise. You should not set this value yourself.