Math::Symbolic::Custom::Transformation 2.01

Math::Symbolic::Custom::Transformation is a Perl extension to the Math::Symbolic module. You're assumed to be remotely familiar with that module throughout the documentation.<br /><br />This package implements transformations of Math::Symbolic trees using Math::Symbolic trees. I'll try to explain what this means in the following paragraphs.<br /><br />Until now, in order to be able to inspect a Math::Symbolic tree, one had to use the low-level Math::Symbolic interface like comparing the top node's term type with a constant (such as T_OPERATOR) and then its operator type with more constants. This has changed with the release of Math::Symbolic::Custom::Pattern.<br /><br />To modify the tree, you had to use equally low-level or even encapsulation-breaking methods. This is meant to be changed by this distribution.<br /><br />SYNOPSIS<br /><br /> use Math::Symbolic::Custom::Transformation;<br /> my $trafo = Math::Symbolic::Custom::Transformation->new(<br /> 'TREE_x + TREE_x' => '2 * TREE_x'<br /> );<br /> <br /> my $modified = $trafo->apply($math_symbolic_tree);<br /> if (defined $modified) {<br /> print "Outermost operator is a sum of two identical trees.<br />";<br /> print "Transformed it into a product. ($modified)<br />";<br /> }<br /> else {<br /> print "Transformation could not be applied.<br />";<br /> }<br /> <br /> # shortcut: new_trafo<br /> use Math::Symbolic::Custom::Transformation qw/new_trafo/;<br /><br /> # use the value() function to have the transformation compute the value<br /> # of the expression after the replacements. simplify{} works similar.<br /> my $another_trafo = new_trafo(<br /> 'TREE_foo / CONST_bar' => 'value{1/CONST_bar} * TREE_foo'<br /> );<br /> <br /> # If you'll need the same transformation but don't want to keep it around in<br /> # an object, just do this:<br /> use Memoize;<br /> memoize('new_trafo');<br /> # Then, passing the same transformation strings will result in a speedup of<br /> # about a factor 130 (on my machine) as compared to complete recreation<br /> # from strings. This is only 20% slower than using an existing<br /> # transformation.

Requirements:	No special requirements
Platforms:	*nix, Linux
Keyword:	Changed,  Lowlevel,  Mathsymboliccustomtransformation 2 01,  Modified,  Module,  Operator,  Print,  Replacements,  Similar,  Simplify,  Strings,  Trafo,  Transformation,  Tree,  Trees,  Works
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