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external:tectomt:tutorial [2009/01/20 14:23] kravalova |
external:tectomt:tutorial [2009/01/22 11:41] kravalova |
====== TectoMT Tutorial ====== | ====== TectoMT Tutorial ====== |
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Welcome at TectoMT Tutorial. This tutorial should take about 2 hours. | Welcome at TectoMT Tutorial. This tutorial should take about 3 hours. |
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TectoMT is a highly modular NLP (Natural Language Processing) software system implemented in Perl programming language under Linux. It is primarily aimed at Machine Translation, making use of the ideas and technology created during the Prague Dependency Treebank project. At the same time, it is also hoped to significantly facilitate and accelerate development of software solutions of many other NLP tasks, especially due to re-usability of the numerous integrated processing modules (called blocks), which are equipped with uniform object-oriented interfaces. | TectoMT is a highly modular NLP (Natural Language Processing) software system implemented in Perl programming language under Linux. It is primarily aimed at Machine Translation, making use of the ideas and technology created during the Prague Dependency Treebank project. At the same time, it is also hoped to significantly facilitate and accelerate development of software solutions of many other NLP tasks, especially due to re-usability of the numerous integrated processing modules (called blocks), which are equipped with uniform object-oriented interfaces. |
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* Your system is Linux | * Your system is Linux |
* Your shell is bash | * Your shell is bash |
* You have basic experience bash and you can read Perl | * You have basic experience with bash and can read basic Perl |
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==== Installation and setup ==== | |
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* Install TrED TODO | |
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* Checkout SVN repository. If you are running this installation in computer lab in Prague, you have checkout the repository into directory /home/BIG (because data quotas don't apply here): | |
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| ==== Installation and setup ==== |
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| * Checkout SVN repository. If you are running this installation in computer lab in Prague, you have to checkout the repository into directory ''/home/BIG'' (because data quotas don't apply here): |
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<code bash> | <code bash> |
</code> | </code> |
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* In ''tectomt/install/'' run ./install.sh: | * In ''tectomt/install/'' run ''./install.sh'': |
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<code bash> | <code bash> |
source ~/BIG/tectomt/config/init_devel_environ.sh | source ~/BIG/tectomt/config/init_devel_environ.sh |
</code> | </code> |
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| * In your ''.bash_profile'' file, add line |
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| <code bash> |
| source .bashrc |
| </code> |
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===== TectoMT Architecture ===== | ===== TectoMT Architecture ===== |
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In TectoMT, there is the following hierarchy of processing units (software components that process data): | In TectoMT, there is the following hierarchy of processing units (software components that process data): |
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* The basic units are blocks. They serve for some very limited, well defined, and often linguistically interpretable tasks (e.g., tokenization, tagging, parsing). Blocks are not parametrizable. Technically, blocks are Perl classes inherited from ''TectoMT::Block''. The blocks repository is in ''libs/blocks/''. | * The basic units are blocks. They serve for some very limited, well defined, and often linguistically interpretable tasks (e.g., tokenization, tagging, parsing). Technically, blocks are Perl classes inherited from ''TectoMT::Block'', each saved in a separate file. The blocks repository is in ''libs/blocks/''. |
* To solve a more complex task, selected blocks can be chained into a block sequence, called also a scenario. Technically, scenarios are instances of ''TectoMT::Scenario'' class, but in some situations (e.g. on the command line) it is sufficient to specify the scenario simply by listing block names separated with spaces. | * To solve a more complex task, selected blocks can be chained into a block sequence, called also a scenario. Technically, scenarios are instances of ''TectoMT::Scenario'' class, but in some situations (e.g. on the command line) it is sufficient to specify the scenario simply by listing block names separated with spaces. |
* The highest unit is called application. Applications correspond to end-to-end tasks, be they real end-user applications (such as machine translation), or 'only' NLP-related experiments. Technically, applications are often implemented as ''Makefiles'', which only glue the components existing in TectoMT. Some demo applications can be found in ''applications'' | * The highest unit is called application. Applications correspond to end-to-end tasks, be they real end-user applications (such as machine translation), or 'only' NLP-related experiments. Technically, applications are often implemented as ''Makefiles'', which only glue the components existing in TectoMT. Some demo applications can be found in ''applications''. |
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This tutorial itself has its blocks in ''libs/blocks/Tutorial'' and the application in ''applications/tutorial''. | This tutorial itself has its blocks in ''libs/blocks/Tutorial'' and the application in ''applications/tutorial''. |
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{{ external:tectomt:pyramid.gif?300x190|MT pyramid in terms of PDT layers}} | {{ external:tectomt:pyramid.gif?300x190|MT pyramid in terms of PDT layers}} |
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TectoMT blocks repository is saved in ''libs/blocks/''. In correspondence with ..., the blocks are located in directories describing their purpose. | The notion of 'layer' has a combinatorial nature in TectoMT. It corresponds not only to the layer of language description as used e.g. in the Prague Dependency Treebank, but it is also specific for a given language (e.g., possible values of morphological tags are typically different for different languages) and even for how the data on the given layer were created (whether by analysis from the lower layer or by synthesis/transfer). |
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Thus, the set of TectoMT layers is Cartesian product {S,T} x {English,Czech} x {W,M,P,A,T}, in which: | Thus, the set of TectoMT layers is a Cartesian product {S,T} x {English,Czech,...} x {W,M,P,A,T}, in which: |
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* {S,T} distinguishes whether the data was created by analysis or transfer/synthesis (mnemonics: S and T correspond to (S)ource and (T)arget in MT perspective). | * {S,T} distinguishes whether the data was created by analysis or transfer/synthesis (mnemonics: S and T correspond to (S)ource and (T)arget in MT perspective). |
* {W,M,P,A,T...} represents the layer of description in terms of PDT 2.0 (W - word layer, M - morphological layer, A - analytical layer, T - tectogrammatical layer) or extensions (P - phrase-structure layer). | * {W,M,P,A,T...} represents the layer of description in terms of PDT 2.0 (W - word layer, M - morphological layer, A - analytical layer, T - tectogrammatical layer) or extensions (P - phrase-structure layer). |
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//Example//: Block adding Czech morphological tags (pos, case, gender, etc.) can be found in ''libs/blocks/SCzechW_toSCzechM/Simple_tagger.pm''. | Blocks in block repository ''libs/blocks'' are located in directories indicating their purpose in machine translation. |
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| //Example//: Block adding Czech morphological tags (pos, case, gender, etc.) can be found in ''libs/blocks/SCzechW_to_SCzechM/Simple_tagger.pm''. |
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| There are also other directories for other purpose blocks, for example blocks which only print out some information go to ''libs/Print''. Our tutorial blocks are in ''libs/blocks/Tutorial/''. |
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There are also other directories for other purpose blocks, for example blocks which only print out some information go to ''libs/Print''. Our tutorial blocks are in ''libs/Tutorial''. | |
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===== First application ===== | ===== First application ===== |
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Once you have TectoMT installed on your machine, you can find this tutorial in ''applications/tutorial/''. After you cd in to this directory, you can see our plain text sample data in ''sample.txt''. | Once you have TectoMT installed on your machine, you can find this tutorial in ''applications/tutorial/''. After you ''cd'' into this directory, you can see our plain text sample data in ''sample.txt''. |
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Most applications are defined in Makefiles, which describe sequence of blocks to be applied on our data. In our particular ''Makefile'', four blocks are going to be applied on our sample text: sentence segmentation, tokenization, tagging and lemmatization. Since we have our input text in plain text format, the file is going to be converted into ''tmt'' format beforehand (the ''in'' section). | Most applications are defined in Makefiles, which describe sequence of blocks to be applied on our data. In our particular ''Makefile'', four blocks are going to be applied on our sample text: sentence segmentation, tokenization, tagging and lemmatization. Since we have our input text in plain text format, the file is going to be converted into ''tmt'' format beforehand (the ''in'' target in the Makefile). |
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We can run the application: | We can run the application: |
</code> | </code> |
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Our plain text data ''sample.txt'' have been transformed into ''tmt'', internal TectoMT format, and saved into ''sample.tmt''. Then, all four blocks have been loaded and our data has been processed. We can now examine ''sample.tmt'' using a regular text editor. We'll now stop and describe data structure in TectoMT. | Our plain text data ''sample.txt'' have been transformed into ''tmt'', an internal TectoMT format, and saved into ''sample.tmt''. Then, all four blocks have been loaded and our data has been processed. We can now examine ''sample.tmt'' with a text editor (vi, emacs, etc). |
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* One physical file corresponds to one document. | * One physical ''tmt'' file corresponds to one document. |
* A document consists of a sequence of bundles (''<bundle>''), mirroring a sequence of natural language sentences originating from the text. So, for one sentence we have one ''<bundle>''. | * A document consists of a sequence of bundles (''<bundle>''), mirroring a sequence of natural language sentences originating from the text. So, for one sentence we have one ''<bundle>''. |
* Each bundle contains tree shaped sentence representations on various linguistic layers. In our example ''sample.tmt'' we have morphological tree (''SEnglishM'') in each bundle. Later on, also an analytical layer (''SEnglishA'') will appear in each bundle as we proceed with our analysis. | * Each bundle contains tree shaped sentence representations on various linguistic layers. In our example ''sample.tmt'' we have morphological tree (''SEnglishM'') in each bundle. Later on, also an analytical layer (''SEnglishA'') will appear in each bundle as we proceed with our analysis. |
* Trees are formed by nodes and edges. Attributes can be attached only to nodes. Edge's attributes must be equivalently stored as the lower node's attributes. Tree's attributes must be stored as attributes of the root node. | * Trees are formed by nodes and edges. Attributes can be attached only to nodes. Edge's attributes must be equivalently stored as the lower node's attributes. Tree's attributes must be stored as attributes of the root node. |
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===== Changing the scenario ===== | ===== Changing the scenario ===== |
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We'll now add syntax analysis to our scenario by adding four more blocks. Instead of | We'll now add a syntax analysis (dependency parsing) to our scenario by adding three more blocks. Instead of |
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<code bash> | <code bash> |
SEnglishW_to_SEnglishM::Sentence_segmentation_simple \ | SEnglishW_to_SEnglishM::Sentence_segmentation_simple \ |
SEnglishW_to_SEnglishM::Penn_style_tokenization \ | SEnglishW_to_SEnglishM::Penn_style_tokenization \ |
SEnglishW_to_SEnglishM::TagTnT \ | SEnglishW_to_SEnglishM::TagMxPost \ |
SEnglishW_to_SEnglishM::Lemmatize_mtree -- sample.tmt | SEnglishW_to_SEnglishM::Lemmatize_mtree \ |
| -- sample.tmt |
</code> | </code> |
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SEnglishW_to_SEnglishM::Sentence_segmentation_simple \ | SEnglishW_to_SEnglishM::Sentence_segmentation_simple \ |
SEnglishW_to_SEnglishM::Penn_style_tokenization \ | SEnglishW_to_SEnglishM::Penn_style_tokenization \ |
SEnglishW_to_SEnglishM::TagTnT \ | SEnglishW_to_SEnglishM::TagMxPost \ |
SEnglishW_to_SEnglishM::Lemmatize_mtree \ | SEnglishW_to_SEnglishM::Lemmatize_mtree \ |
SEnglishM_to_SEnglishA::McD_parser_local \ | SEnglishM_to_SEnglishA::McD_parser_local \ |
SEnglishM_to_SEnglishA::Fix_McD_Tree \ | SEnglishM_to_SEnglishA::Fix_McD_Tree \ |
SEnglishM_to_SEnglishA::Fill_afun_after_McD -- sample.tmt | SEnglishM_to_SEnglishA::Fill_afun_after_McD \ |
| -- sample.tmt |
</code> | </code> |
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we can examine our ''sample.tmt'' again. Really, an analytical layer ''SEnglishA'' describing a dependency tree with analytical functions (''<afun>'') has been added to each bundle. | we can examine our ''sample.tmt'' again. Really, an analytical layer ''SEnglishA'' describing a dependency tree with analytical functions (''<afun>'') has been added to each bundle. |
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| Blocks can also be parametrized. For syntax parser, we might want to use a smaller but faster model. To achieve this, replace the line |
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| <code bash> |
| SEnglishM_to_SEnglishA::McD_parser_local \ |
| </code> |
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| with |
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| <code bash> |
| SEnglishM_to_SEnglishA::McD_parser_local MT_PARAM_MCD_EN_MODEL=conll_mcd_order2_0.1.model \ |
| </code> |
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You can view the trees in ''sample.tmt'' with TrEd by typing | You can view the trees in ''sample.tmt'' with TrEd by typing |
tmttred sample.tmt | tmttred sample.tmt |
</code> | </code> |
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| Try to click on some nodes to see their parameters (tag, lemma, form, analytical function etc). |
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| //Note//: For more information about tree editor TrEd, see [[http://ufal.mff.cuni.cz/~pajas/tred/ar01-toc.html|TrEd User's Manual]]. |
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This block illustrates some of the most common methods for accessing objects: | This block illustrates some of the most common methods for accessing objects: |
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* ''my @bundles = $document->get_bundles'' - an array of bundles contained in the document | * ''my @bundles = $document<nowiki>-></nowiki>get_bundles()'' - an array of bundles contained in the document |
* ''my $root_node = $bundle->get_tree($layer_name);'' - the root node of the tree of the given type in the given bundle | * ''my $root_node = $bundle<nowiki>-></nowiki>get_tree($layer_name)'' - the root node of the tree of the given type in the given bundle |
* ''my @children = $node->get_children;'' - array of the node's children | * ''my @children = $node<nowiki>-></nowiki>get_children()'' - array of the node's children |
* ''my @descendants = $node->get_descendants;'' - array of the node's children and their children and children of their children ... | * ''my @descendants = $node<nowiki>-></nowiki>get_descendants()'' - array of the node's children and their children and children of their children ... |
* ''my $parent = $node->get_parent;'' - parent node of the given node, or undef for root | * ''my $parent = $node<nowiki>-></nowiki>get_parent()'' - parent node of the given node, or undef for root |
* ''my $root_node = $node->get_root;'' - the root node of the tree into which the node belongs | * ''my $root_node = $node<nowiki>-></nowiki>get_root()'' - the root node of the tree into which the node belongs |
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Attributes of documents, bundles or nodes can be accessed by attribute getters and setters, for example: | Attributes of documents, bundles or nodes can be accessed by attribute getters and setters, for example: |
* ''$node->get_attr($attr_name);'' | |
* ''$node->set_attr($attr_name, $attr_value);'' | |
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Our tutorial block ''Print_node_info.pm'' is ready to use. You only need to add this block to our scenario: | * ''$node<nowiki>-></nowiki>get_attr($attr_name)'' |
| * ''$node<nowiki>-></nowiki>set_attr($attr_name, $attr_value)'' |
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| Some interesting attributes on morphologic layer are ''form'', ''lemma'' and ''tag''. Some interesting attributes on analytical layer are ''afun'' (analytical function) and ''ord'' (surface word order). To reach ''form'', ''lemma'' or ''tag'' from analytical layer, that is, when calling this attribute on an ''a-node'', you use ''$a_node->get_attr('m/form')'' and the same way for ''lemma'' and ''tag''. The easiest way to see the node attributes is to click on the node in TrEd: |
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| <code bash> |
| tmttred sample.tmt |
| </code> |
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| Our tutorial block ''Print_node_info.pm'' is ready to use. You only need to add this block to our scenario, e.g. as a new Makefile target: |
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<code bash> | <code bash> |
</code> | </code> |
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Try to change the block so that it prints out the information only for verbs. (You need to look at attribute ''tag'' at the ''m'' level). The tagset used is Penn Treebank Tagset. | Try to change the block so that it prints out the information only for verbs. (You need to look at an attribute ''tag'' at the ''m'' level). The tagset used is Penn Treebank Tagset. |
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It is assumed that finite clauses can be translated independently, which would reduce computational complexity or make parallel translation possible. We could even use hybrid translation - each finite clause could be translated by the most self-confident translation system. In this task, we are going to split the sentence into finite clauses. | It is assumed that finite clauses can be translated independently, which would reduce computational complexity or make parallel translation possible. We could even use hybrid translation - each finite clause could be translated by the most self-confident translation system. In this task, we are going to split the sentence into finite clauses. |
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==== Task ==== | ==== Task ==== |
A block which, given an analytical tree (''SEnglishA''), fills each ''a-node'' with boolean attribute ''is_head'' which is set to ''1'' if the ''a-node'' corresponds to a finite verb, and to ''0'' otherwise. | A block which, given an analytical tree (''SEnglishA''), fills each ''a-node'' with boolean attribute ''is_clause_head'' which is set to ''1'' if the ''a-node'' corresponds to a finite verb, and to ''0'' otherwise. |
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==== Instructions ==== | ==== Instructions ==== |
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There is a block template with hints in ''libs/blocks/Tutorial/Mark_heads.pm''. You should edit the block so that the ouput of this block is the same a-tree, in addition with attribute ''is_head'' attached to each ''a-node''. There is also a printing block ''libs/blocks/Print_finite_clauses.pm'' which will print out the ''a-nodes'' grouped by clauses: | There is a block template with hints in ''libs/blocks/Tutorial/Mark_heads.pm''. You should edit the block so that the output of this block is the same a-tree, in addition with attribute ''is_clause_head'' attached to each ''a-node''. There is also a printing block ''libs/blocks/Print_finite_clauses.pm'' which will print out the ''a-nodes'' grouped by clauses: |
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<code bash> | <code bash> |
brunblocks -S -o \ | brunblocks -S -o \ |
Tutorial::Mark_heads \ | Tutorial::Mark_heads \ |
Tutorial::Print_finite_clauses -- sample.tmt | Tutorial::Print_finite_clauses \ |
| -- sample.tmt |
</code> | </code> |
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You are going to need these methods: | You are going to need these methods: |
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* ''my root = $bundle->get_tree('tree_name')'' | * ''my $root = $bundle<nowiki>-></nowiki>get_tree('tree_name')'' |
* ''my $attr = $node->get_attr('attr_name')'' | * ''my $attr = $node<nowiki>-></nowiki>get_attr('attr_name')'' |
* ''$node->set_attr('attr_name',$attr_value)'' | * ''$node<nowiki>-></nowiki>set_attr('attr_name',$attr_value)'' |
* ''my @eff_children = $node->get_eff_children()'' | * ''my @eff_children = $node<nowiki>-></nowiki>get_eff_children()'' |
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//Note//: ''get_children'' returns topological node children in a tree, while ''get_eff_children'' returns node children in a linguistic sense. Mostly, these do not differ. | //Note//: ''get_children()'' returns topological node children in a tree, while ''get_eff_children()'' returns node children in a linguistic sense. Mostly, these do not differ. If interested, see Figure 1 in [[http://ufal.mff.cuni.cz/pdt2.0/doc/tools/tred/bn-tutorial.html|btred tutorial]]. |
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| //Hint//: Finite clauses in English usually require grammatical subject to be present. |
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| ==== Advanced version ==== |
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//Advanced version//: The output of our block might still be incorrect in special cases - we don't solve coordination and subordinate conjunctions. | The output of our block might still be incorrect in special cases - we don't solve coordination (see the second sentence in sample.txt) and subordinate conjunctions. |
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==== SVO typology ==== | |
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TODO | |
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| ==== SVO to SOV ==== |
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| **Motivation**: During translation from an SVO based language (e.g. English) to an SOV based language (e.g. Korean) we might need to change the word order from SVO to SOV. |
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| **Task**: Change the word order from SVO to SOV. |
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==== Prepositions ==== | **Instructions**: |
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In dependency approach a question "where to hang prepositions" arises. In praguian style (PDT), prepositions are heads of the subtree and the noun/pronoun is dependent on the preposition. However, another ordering might be preferable: The noun/pronoun might be the head of subtree, while the preposition would take the role of a modifier. | * You can use block template in ''libs/blocks/BlockTemplate.pm''. |
| * To find an object to a verb, look for objects among effective children of a verb (''$child<nowiki>-></nowiki>get_attr('afun') eq 'Obj' ''). That implies working on analytical layer. |
| * For debugging, a method returning surface word order of a node is useful: ''$node<nowiki>-></nowiki>get_attr('ord')''. It can be used to print out nodes sorted by attribute ''ord''. |
| * Once you have node ''$object'' and node ''$verb'', use method ''$object<nowiki>-></nowiki>shift_before_node($verb)''. This method takes the whole subtree under node ''$object'' and re-counts the attributes ''ord'' (surface word order) so that all nodes in subtree under ''$object'' have smaller ''ord'' than ''$verb''. That is, the method rearranges the surface word order from VO to OV. |
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TODO obrazek | **Advanced version**: This solution shifts object (or more objects) of a verb just in front of that verb node. So f.e.: //Mr. Brown has urged MPs.// changes to: //Mr. Brown has MPs urged.// You can try to change this solution, so the final sentence would be: //Mr. Brown MPs has urged.// You may need a method ''$node->shift_after_subtree($root_of_that_subtree)''. Subjects should have attribute '''afun' eq 'Sb'''. |
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The task is to rehang all prepositions as indicated at the picture. You may assume that prepositions have at most 1 child. | |
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You are going to need these new methods: | |
* ''my @children = $node->get_children'' | |
* ''my $parent = $node->get_parent'' | |
* ''$node->set_parent($parent)'' | |
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//Hint//: | |
* On analytical layer, you can use this test to recognize prepositions: ''$afun eq 'AuxP' '' | |
* You can use block template in ''libs/blocks/BlockTemplate.pm''. To see the results, you can again use TrEd (''tmttred sample.tmt'') | |
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//Advanced version//: What happens in case of multiword prepositions? For example, ''because of'', ''instead of''. Can you handle it? | |
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===== Further information ===== | |
* [[http://ufallab2.ms.mff.cuni.cz/~bojar/cruise_control_tmt/last_doc/generated/guide/guidelines.html|TectoMT Developer's Guide]] - obsolete | |
* Questions? Ask ''kravalova'' at ''ufal.mff.cuni.cz'' | |
* Solutions to this tutorial tasks are in ''libs/blocks/Tutorial/*solution.pm''. | |
* [[http://ufal.mff.cuni.cz/~pajas/tred/|TrEd]] - tree editor | |
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| ==== Prepositions ==== |
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| {{ external:tectomt:preps.png?200x80|Prepositions example}} |
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| **Motivation**: In dependency approach a question "where to hang prepositions" arises. In praguian style (PDT), prepositions are heads of the subtree and the noun/pronoun is dependent on the preposition. However, another ordering might be preferable: The noun/pronoun might be the head of subtree, while the preposition would take the role of a modifier. |
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| **Task**: The task is to rehang all prepositions as indicated at the picture. You may assume that prepositions have at most 1 child. |
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| ** Instructions**: |
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| You are going to need these new methods: |
| * ''my @children = $node<nowiki>-></nowiki>get_children()'' |
| * ''my $parent = $node<nowiki>-></nowiki>get_parent()'' |
| * ''$node<nowiki>-></nowiki>set_parent($parent)'' |
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| //Hint//: |
| * On analytical layer, you can use this test to recognize prepositions: ''$node<nowiki>-></nowiki>get_attr('afun') eq 'AuxP' '' |
| * To see the results, you can again use TrEd (''tmttred sample.tmt'') |
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| **Advanced version**: What happens in case of multiword prepositions? For example, ''because of'', ''instead of''. Can you handle it? |
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| ===== Further information ===== |
| * [[http://ufallab2.ms.mff.cuni.cz/~bojar/cruise_control_tmt/last_doc/generated/guide/guidelines.html|TectoMT Developer's Guide]] |
| * Questions? Ask ''kravalova'' at ''ufal.mff.cuni.cz'' |
| * Solutions to this tutorial tasks are in ''libs/blocks/Tutorial/*solution*.pm''. |
| * [[http://ufal.mff.cuni.cz/~pajas/tred/|TrEd]], [[http://ufal.mff.cuni.cz/~pajas/tred/ar01-toc.html|TrEd User's Manual]] - tree editor |
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