Math::Symbolic::Constant(3pm)

1Math::Symbolic::ConstanUts(e3r)Contributed Perl DocumentMaattiho:n:Symbolic::Constant(3)
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NAME

6       Math::Symbolic::Constant - Constants in symbolic calculations
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SYNOPSIS

9         use Math::Symbolic::Constant;
10         my $const = Math::Symbolic::Constant->new(25);
11         my $zero  = Math::Symbolic::Constant->zero();
12         my $one   = Math::Symbolic::Constant->one();
13         my $euler = Math::Symbolic::Constant->euler();
14         # e = 2.718281828...
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DESCRIPTION

17       This module implements numeric constants for Math::Symbolic trees.
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19   EXPORT
20       None by default.
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METHODS

23   Constructor new
24       Takes hash reference of key-value pairs as argument.  Special case: a
25       value for the constant instead of the hash.  Returns a
26       Math::Symbolic::Constant.
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28   Constructor zero
29       Arguments are treated as key-value pairs of object attributes.  Returns
30       a Math::Symbolic::Constant with value of 0.
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32   Constructor one
33       Arguments are treated as key-value pairs of object attributes.  Returns
34       a Math::Symbolic::Constant with value of 1.
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36   Constructor euler
37       Arguments are treated as key-value pairs of object attributes.  Returns
38       a Math::Symbolic::Constant with value of e, the Euler number.  The
39       object has its 'special' attribute set to 'euler'.
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41   Constructor pi
42       Arguments are treated as key-value pairs of object attributes.  Returns
43       a Math::Symbolic::Constant with value of pi.  The object has its
44       'special' attribute set to 'pi'.
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46   Method value
47       value() evaluates the Math::Symbolic tree to its numeric
48       representation.
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50       value() without arguments requires that every variable in the tree
51       contains a defined value attribute. Please note that this refers to
52       every variable object, not just every named variable.
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54       value() with one argument sets the object's value if you're dealing
55       with Variables or Constants. In case of operators, a call with one
56       argument will assume that the argument is a hash reference. (see next
57       paragraph)
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59       value() with named arguments (key/value pairs) associates variables in
60       the tree with the value-arguments if the corresponging key matches the
61       variable name.  (Can one say this any more complicated?) Since version
62       0.132, an equivalent and valid syntax is to pass a single hash
63       reference instead of a list.
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65       Example: $tree->value(x => 1, y => 2, z => 3, t => 0) assigns the value
66       1 to any occurrances of variables of the name "x", aso.
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68       If a variable in the tree has no value set (and no argument of value
69       sets it temporarily), the call to value() returns undef.
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71   Method signature
72       signature() returns a tree's signature.
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74       In the context of Math::Symbolic, signatures are the list of variables
75       any given tree depends on. That means the tree "v*t+x" depends on the
76       variables v, t, and x. Thus, applying signature() on the tree that
77       would be parsed from above example yields the sorted list ('t', 'v',
78       'x').
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80       Constants do not depend on any variables and therefore return the empty
81       list.  Obviously, operators' dependencies vary.
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83       Math::Symbolic::Variable objects, however, may have a slightly more
84       involved signature. By convention, Math::Symbolic variables depend on
85       themselves. That means their signature contains their own name. But
86       they can also depend on various other variables because variables
87       themselves can be viewed as placeholders for more compicated terms. For
88       example in mechanics, the acceleration of a particle depends on its
89       mass and the sum of all forces acting on it. So the variable
90       'acceleration' would have the signature ('acceleration', 'force1',
91       'force2',..., 'mass', 'time').
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93       If you're just looking for a list of the names of all variables in the
94       tree, you should use the explicit_signature() method instead.
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96   Method explicit_signature
97       explicit_signature() returns a lexicographically sorted list of
98       variable names in the tree.
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100       See also: signature().
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102   Method special
103       Optional argument: sets the object's special attribute.  Returns the
104       object's special attribute.
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106   Method to_string
107       Returns a string representation of the constant.
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109   Method term_type
110       Returns the type of the term. (T_CONSTANT)
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AUTHOR

113       Please send feedback, bug reports, and support requests to the
114       Math::Symbolic support mailing list: math-symbolic-support at lists dot
115       sourceforge dot net. Please consider letting us know how you use
116       Math::Symbolic. Thank you.
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118       If you're interested in helping with the development or extending the
119       module's functionality, please contact the developers' mailing list:
120       math-symbolic-develop at lists dot sourceforge dot net.
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122       List of contributors:
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124         Steffen Mueller, symbolic-module at steffen-mueller dot net
125         Stray Toaster, mwk at users dot sourceforge dot net
126         Oliver Ebenhoeh
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NAME

SYNOPSIS

DESCRIPTION

METHODS

AUTHOR

SEE ALSO