NAME

SYNOPSIS

  use Math::SimpleVariable;

  # Make a variable
  my $foo = new Math::SimpleVariable(name => 'foo', value => 0.3);

  # Some of the available accessors
  # Note that many are identical, but you might want to change
  # their behaviour in derived variable classes...
  my $name = $foo->name();       # yields 'foo'
  print $foo->stringify(), "\n"; # prints 'foo'
  my $id = $foo->id();           # yields 'foo'
  my $value = $foo->value();     # yields 0.3
  print $foo->evaluate(), "\n";  # prints 0.3

  # Make a second variable
  my $bar = $foo->clone();
  $bar->{name} = 'bar';      # changes the name (and as a consequence the id())
  print $bar->value(), "\n"; # prints the same value, 0.3

DESCRIPTION

Math::SimpleVariable has two data fields - name and value - that can be accessed and modified as if the variable object is a hash. E.g.

    $var->{name} = 'foo';

sets the name of the object $var to 'foo', and

    my $val = $var->{value};

reads the value of the $var object into $val.

In addition, the following accessor methods are available for Math::SimpleVariable objects:

$var->name()

Returns $var->{name}

$var->id()

Returns $var->name() for Math::SimpleVariable objects. The purpose of id() is to provide some unique identifier when using variables in some higher level concept, e.g. a matrix representation of a set of equations. Depending on your needs, you might want to change the implementation of id() in derived classes.

stringify()

Returns a printable representation of the variable. For Math::SimpleVariable objects, returns $var->name(). Again, you might want to override this for derived classes.

value()

Returns $var->{value}

evaluate()

Returns a numerical evaluation of the variable. For Math::SimpleVariable objects, returns $var->value(). You might want to override this behaviour in derived classes, athough I cannot think of any place where this might come in useful :-). evaluate() is still there for reasons of orthogonality.

SEE ALSO

VERSION

AUTHOR

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