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Experiment scripts

In the directory "new-scripts" you find some scripts that facilitate conducting experiments. An experiment is conducted in three stages: Generation of experiments, fetching of results and production of reports. Each stage has its own generic main module: experiments.py, resultfetcher.py and reports.py. These modules provide useful classes and methods and can be imported by scripts that actually define concrete actions. For the fast downward planning system the example scripts that use these modules are downward_experiments.py, downward-resultfetcher.py and downward-reports.py. Together they can be used to conduct Fast Downward experiments. Passing -h on the commandline gives you an overview of each script's commands.

Conducting a local Fast Downward experiment for the impatient

   1 # Preprocessing
   2 ./downward_experiments.py expname -s TEST --preprocess
   3 ./expname-p/run
   4 ./resultfetcher.py expname-p
   5 
   6 # Build and run the experiment
   7 ./downward_experiments.py expname -c downward_configs.py:yY -s TEST
   8 ./expname/run
   9 
  10 # Make reports
  11 ./downward-resultfetcher.py expname
  12 ./downward-reports.py expname

Below you find a detailed description of the above steps.

Generate an experiment

./downward_experiments.py expname -c downward_configs.py:yY -s TEST

Generates a planning experiment for the suite TEST in the directory "expname". The planner will use the configuration string yY found in the file downward_configs.py. When you invoke the script you can specify on the command line whether you want the experiment to be run locally or on the gkigrid. You can also directly set the timeout, memory limit, number of processes, etc.

Before you can execute that command however you have to run it once with the --preprocess parameter. This will generate a preprocessing experiment. After you have run this preprocessing experiment and fetched the results with ./resultfectcher.py you can generate the search experiment.

Local experiments can be started by running

./expname/run

Gkigrid experiments are submitted to the queue by running

qsub expname/expname.q

Fetch and parse results

./downward-resultfetcher.py expname

Traverses the directory tree under "expname" and parses each run's experiment files. The results are written into a new directory structure under "expname-eval". In the process each run's properties file is read and its "id" determines the run's destination directory in the new directory tree. By default only the properties file is copied and the parsed values are added to it. To copy all files you can pass the "--copy-all" option.

Combine results of multiple experiments

It is possible to combine the results of multiple experiments by running the above command on all the experiment directories while specifying the target evaluation directory. If you don't specify the evaluation directory it defaults to "exp-name-eval". An example would be

./downward-resultfetcher.py exp1 --dest my-eval-dir
./downward-resultfetcher.py exp2 --dest my-eval-dir

Make reports

./downward-reports.py expname-eval

Reads all properties files found under "test-exp-eval" and generates a big dataset from them. This dataset is serialized into the "expname-eval" directory for faster future reports. If you want to reload the information directly from the properties files, pass the "--reload" parameter.

The dataset is then used to generate a report. By default this report contains absolute numbers, writes a Latex file and analyzes all numeric attributes found in the dataset. You can however choose only a subset of attributes and filter by configurations or suites, too. A detailed description of the available parameters can be obtained by invoking downward-reports.py -h.

Show significant changes only

You can also compare two configs/revisions and only show the rows that have changed significantly. To do so select a relative report (-r rel) and specify a percent number (--change number). The report will then only contain those rows for which the two values in the row have changed by more than number percent. Here is an example:

   1 ./downward-reports.py expname-eval/ -a expanded -r rel --change 5

This will only show the rows where the number of expansions has changed by more than five percent.

Making a problem suite from results

The downward-reports.py also gives you the possibility to create a new problem suite based on the results of an experiment. To select a subset of problems you can specify filters for the set of the runs. E.g. to get a list of problems that had more than 1000 states expanded in the ou config, you could issue the following command:

   1 ./downward-reports.py expname-eval --filter config:eq:ou expanded:gt:1000

(Remember to pass the correct name for config, it might not be just its nickname) As you can see the format of a filter is <attribute_name>:<operator from the operator module>:<value>. If the expression operator(run[attribute], value) evaluates to True, the run's planning problem is not removed from the result list.

Comparing different revisions

If you want to compare different revisions of fast-downward, you can write your own script that importes python module downward_experiments.py. This module provides an easy way to select and compare specific revisions of the three subsystems (translate, preprocess and search). It does so by using the experiments.py module. The usage is pretty simple. As an example we will look at the code that has been used to get some information about issue69 from the issue tracker (The code resides in issue69.py):

   1 from downward_experiments import *
   2 
   3 combinations = [
   4     (TranslatorSvnCheckout(), PreprocessorSvnCheckout(), PlannerSvnCheckout(rev=3612)),
   5     (TranslatorSvnCheckout(), PreprocessorSvnCheckout(), PlannerSvnCheckout(rev=3613)),
   6     (TranslatorSvnCheckout(), PreprocessorSvnCheckout(), PlannerSvnCheckout(rev='HEAD')),
   7                ]
   8                
   9 build_experiment(combinations)

This code builds an experiment that compares three revisions of the search component; rev 3612, rev 3613 and the latest (HEAD) revision. As you can see, the translation and preprocessing components have been assigned no explicit revision. This can be done since all different Checkouts default to the HEAD or tip revision. The different Checkout classes also have another keyword parameter called repo that can be used when you don't want to checkout a subsystem from trunk.

One combination of three checkouts results in one run of the fast-downward system (translate -> preprocess -> search) for each problem and configuration. Obviously you should checkout different revisions of the subsystems you want to compare and let the other subsystems have the same revisions in all runs.

As another example, if you want to compare your modified translator in your own branch with the one from trunk, you could do:

   1 combinations = [
   2     (TranslatorSvnCheckout(repo='svn+ssh://downward/branches/my-own-translator/downward/translate', rev=1234), PreprocessorSvnCheckout(), PlannerSvnCheckout()),
   3     (TranslatorSvnCheckout(), PreprocessorSvnCheckout(), PlannerSvnCheckout()),
   4                ]

When running your script, you'll be prompted to specify the suites and configurations. You have the same options here as for the downward_experiments.py script.

Example: Issue 7

You don't have to supply new Checkout instances for each combination. See the comparison experiment for issue7 as an example. This code compares three different revisions of the translator in an external branch with the checked-in translator from trunk. The revisions for the preprocessor and the search component remain the same for all combinations.

   1 from downward_experiments import *
   2 
   3 branch = 'svn+ssh://downward-svn/branches/translate-andrew/downward/translate'
   4 
   5 preprocessor = PreprocessorSvnCheckout()
   6 planner = PlannerSvnCheckout(rev=3842)
   7 
   8 combinations = [
   9     (TranslatorSvnCheckout(repo=branch, rev=3827), preprocessor, planner),
  10     (TranslatorSvnCheckout(repo=branch, rev=3829), preprocessor, planner),
  11     (TranslatorSvnCheckout(repo=branch, rev=3840), preprocessor, planner),
  12     (TranslatorSvnCheckout(rev=4283), preprocessor, planner),
  13                ]
  14                
  15 build_experiment(combinations)

Example: Checking impacts of your changes

If you want to check the impacts of your changes in your working copy with the latest checked-in revision you could pass the following combinations to the function build_experiment() in downward_experiments.py.

   1 from downward_experiments import *
   2 
   3 combinations = [
   4     (TranslatorHgCheckout(rev='tip'), PreprocessorHgCheckout(rev='tip'), PlannerHgCheckout(rev='tip')),
   5     (TranslatorHgCheckout(rev='WORK'), PreprocessorHgCheckout(rev='WORK'), PlannerHgCheckout(rev='WORK')),
   6     ]
   7                
   8 build_experiment(combinations)

This command creates an experiment that compares the subsystems in the working copy with the versions of the subsystems in the tip revision. You can also see that you can set rev to 'WORK' to use the working copy.