Dear maintainers, contributors, Hope this email finds you well.
This mail can be considered as a status report for detailing next week's plan in addition to seeking feedback/ suggestions regarding the project. After a fruitful discussion with my mentors Nick, Flammie and Francis, we have agreed on implementing the supervised way of weighing automata as follows: The command will look like: lt-weight transducer.bin corpus.tagged transducer.bin: A FST compiled using lttoolbox. corpus.tagged: A tagged corpus that will be used to estimate the weights. The weighting will be done by composing the main "unweighted" FST with a set of simple FSTs that are generated for each token. A simplified example: If the main FST had an edge a:b::0 and the estimated weight for this edge is W, then The main FST will be composed with a simple FST of an edge b:b::w generating a new FST with an edge a:b::W. To achieve this, I will create a new shell script that makes use of hfst's compose (Instead of implementing/adding a compose function to the lttoolbox). We will approve and use this approach if the prototype has proven to be functioning as expected. The shell script will work as follows: 1) lt-print will be used to convert the FST to at&t format. 2) The weights will be estimated from the tagged corpus by counting the unigram lexical forms (A clever set of shell commands can do the job but I am not an expert in shell scripting so it will take me some time - I am open to suggestions/ sources/ examples for doing so). 3) For each weighted string, hfst-str2fst (or the corresponding regex version) will be used to generate simple FSTS. 4) The FSTs will be composed using hfst-compose. 5) The final FST will be converted to at&t format. 6) lt-comp will be be used to regenerate a weighted FST that is compatable with all the tools that rely on apertium. In this version, We will just use unigram counts for the lexical forms to estimate the weights. Additionally, The weight will be assigned to the final state and won't be distributed among the edges (We will most probably want to change this later). On the other hand, I will try to improve the list of publications/ideas that will be used to weigh automata in an unsupervised way. I would be grateful if you can share with me resources/ ideas regarding this part. Finally, Do you have recommendations for tagged corpora that can be used throughout the project for benchmarking? I am using this English Tagged corpus from the apertium-eng repository (https://github.com/apertium/apertium-eng/blob/master/texts/eng.tagged) It would be better if we can do benchmarking on corpora and FSTs of different sizes and complexity. Thanks and looking forward to hearing from you. Your suggestions, feedback, feature requests are more than welcome. Best Regards, Amr ________________________________ From: Amr Mohamed Hosny Anwar Sent: Sunday, May 19, 2019 12:50:52 AM To: apertium-stuff Cc: nlhow...@gmail.com Subject: GSoC 19: Unsupervised weighting of automata - Implementing the supervised method of weighing autoamata Dear maintainers, contributors, Hope this email finds you well. This mail can be considered as a status report for detailing next week's plan in addition to seeking feedback/ suggestions regarding the project. Best Regards, Amr Keleg
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