NAME
Math::Symbolic::Variable - Variable in symbolic calculations
SYNOPSIS
use Math::Symbolic::Variable;
my $var1 = Math::Symbolic::Variable->new('name');
$var1->value(5);
my $var2 = Math::Symbolic::Variable->new('x', 2);
my $var3 = Math::Symbolic::Variable->new(
{
name => 'variable',
value => 1,
}
);DESCRIPTION
This class implements variables for Math::Symbolic trees. The objects are overloaded in stringification context to return their names.
EXPORT
None by default.
METHODS
Constructor new
First argument is expected to be a hash reference of key-value pairs which will be used as object attributes.
Special case: First argument is not a hash reference. In this case, first argument is treated as variable name, second as value. This special case disallows cloning of objects (when used as object method).
Returns a Math::Symbolic::Variable.
Method value
value() evaluates the Math::Symbolic tree to its numeric representation.
value() without arguments requires that every variable in the tree contains a defined value attribute. Please note that this refers to every variable object, not just every named variable.
value() with one argument sets the object's value.
value() with named arguments (key/value pairs) associates variables in the tree with the value-arguments if the corresponging key matches the variable name. (Can one say this any more complicated?)
Example: $tree->value(x => 1, y => 2, z => 3, t => 0) assigns the value 1 to any occurrances of variables of the name "x", aso.
Method set_value
set_value() returns nothing.
set_value() requires named arguments (key/value pairs) that associate variable names of variables in the tree with the value-arguments if the corresponging key matches the variable name. (Can one say this any more complicated?)
Example: $tree->set_value(x => 1, y => 2, z => 3, t => 0) assigns the value 1 to any occurrances of variables of the name "x", aso.
As opposed to value(), set_value() assigns to the variables permanently and does not evaluate the tree.
Method name
Optional argument: sets the object's name. Returns the object's name.
Method to_string
Returns a string representation of the variable.
Method term_type
Returns the type of the term. (T_VARIABLE)
AUTHOR
Steffen Mueller, <symbolic-module at steffen-mueller dot net>
New versions of this module can be found on http://steffen-mueller.net or CPAN.