A: Astro-WISE for Astronomical Wide-field Imaging System Europe, is an E.U. consortium and associated information system dedicated to the handling of wide-field image data resulting from large astronomical surveys. Please see the main page for a complete description.
A: The Astro-WISE Environment, or simply AWE, is the information system built to handle this flood of astronomical data. Start here to learn more about it.
A: The Astro-WISE Environmentis written mainly in the Python programming/scripting language. There are also Python utility modules written in C (see the HOW-TO Introduction), but these are wrapped in Python to interface with the system.
A: See the Introduction HOW-TO for a complete list of what AWE offers.
A: Do you have an AWE account? If not, please contact an Astro-WISE representative.
A: Anonymous CVS requires a special password and is not available to just anybody. Contact an Astro-WISE representative for help. Anonymous CVS is read-only access to the software. When ready to contribute to the code-base, you will need a full account. Again, see an Astro-WISE representative.
A: $AWEPIPE is the environmental variable that should point to your
``awe'' checkout, the code-base for AWE (e.g., 1#1
A: There are many options, but the typical one is to simply use AWE on a properly configured system:
...]$ awe Python 2.3.5 (#4, Aug 15 2005, 11:45:46) [GCC 3.4.3 20050227 (Red Hat 3.4.3-22.1)] on linux2 Type "help", "copyright", "credits" or "license" for more information. Welcome to the Astro-WISE Environment . . . awe>
You can also temporarily modify environmental variables that AWE uses so that AWE starts with a different configuration:
...]$ env AWEPIPE=~/test-awe/ awe or ...]$ env database_engine= awe
The first example causes AWE to use a code-base located in a specified
A: The first place any new user should look for documentation is the HOW-TOs
A: Docstrings are the inline comments added to Python code that allow for an automated documentation system called PyDoc. Docstrings are contained within triple quotes:
'''this is a docstring''' """this is also a docstring""" # this is just a comment
A: First, make sure you are in the top-level directory (or whatever directory you want fully updated) and issue the following command:
...]$ cvs -q update -dPA
If you chose a specific tagged version, that tag becomes sticky. The last option overrides this stickiness. See the cvs(1) man page for complete information on CVS.
A: are you sure that you retrieved every single sub-directory of the Astro-WISE system during checkout? Using a simple cvs co can sometimes result in some sub-directories not being retrieved. If you suspect that something like this might be the problem, go to the directory where the specific sub-directory should have been located and type cvs update -d.
A: To switch to the most recent check out use
... awe]$ cvs -q update -dPA
and to switch back to the AWBASE version, use
... awe]$ cvs -q update -r AWBASE -dP
in the `awe' directory.
A: Please look at the Observations Scheduling HOW-TO for guidelines.
A: AWE was created specifically for OmegaCAM and will handle OmegaCAM data ``out-of-the-box''. There is also support for the instruments listed on the Supported Data Sources page. If your instrument is not there, contact an AWE representative for verification and have a look at the New Instrument HOW-TO to get started.
A: In order for raw data to be processed in the Astro-WISE system, it must first be ingested, or imported into the system. Please see the Data Ingestion HOW-TO for a complete description.
A: Data in AWE is catagorized by purpose:
A: The filenames were converted to AWE cannonical names of the form:
<instrument>.<date_obs>.fits or <instrument>.<date_obs>_n.fits
The first from is for multi-extension FITS images, the second is for single-extension FITS images where n is the extension number.
A: An observation night is based on the local date at sunset and not on UTC. See the Dates and Times HOW-TO for more information.
A: In UTC only.
Q: What is the parallel processing interface in AWE?
A: The DPU (Distruibuted Processing Unit) is used to run tasks on the parallel compute cluster. It is initialized when AWE starts:
...]$ awe . . . Importing Astro-WISE packages. Please wait... Initializing Distributed Processing Unit... Current profile: . . . awe>
To initiallize it manually, use this method:
awe> from astro.recipes.mods.dpu import Processor awe> my_dpu = Processor(Env['dpu_name'])
Q: How do I find the instruments, task identifiers, and options supported by the DPU's run method: dpu.run()?
A: This information is somewhat hidden. The supported instrument list can be seen by querying the HeaderTranslatorFactory:
awe> from astro.instrument.HeaderTranslatorFactory import supported_instrument_list awe> print supported_instrument_list
Task identifiers can be found like this:
awe> from astro.recipes.mods import Pipeline awe> for id in Pipeline.get_available_sequence_identifiers(): print id
And the options can be printed in this way:
awe> from astro.recipes.util.ArgumentParser import ArgumentParser awe> for opt in ArgumentParser().opts: print opt
This gives you a list of tuples of the form (short_opt, long_opt, definition).
A: Simply speaking, namespace is all modules, classes, attributes, and methods available in the current scope (i.e., level). If the module, class, attribute, or method you need is not visible in the current namespace, then it cannot be used. It is either loaded within the namespace at a different scope, or it is not there at all. The builtins dir() and help() allow you to explore the namespace.
dir() without any arguments gives the namespace of the current scope. It typically will give Python builtins and any modules pre-loaded at startup or during the current session. Calling dir() with a module, class, attribute, or method as the argument will give you the namespace at that level or an arbitrary level:
awe> dir() ['__builtin__', '__builtins__', '__doc__', '__file__', '__name__', '__version_ _', 'astro', 'atexit', 'os', 'pydoc', 'readline', 'rlcompleter', 'sys', 'users tartup'] awe> dir(os) ['EX_CANTCREAT', 'EX_CONFIG', 'EX_DATAERR', 'EX_IOERR', 'EX_NOHOST', 'EX_NOINP UT', 'EX_NOPERM', 'EX_NOUSER', 'EX_OK', 'EX_OSERR', 'EX_OSFILE', 'EX_PROTOCOL' . . . ttyname', 'umask', 'uname', 'unlink', 'unsetenv', 'utime', 'wait', 'waitpid', 'walk', 'write'] awe> dir(os.write) ['__call__', '__class__', '__cmp__', '__delattr__', '__doc__', '__getattribute __', '__hash__', '__init__', '__module__', '__name__', '__new__', '__reduce__' , '__reduce_ex__', '__repr__', '__self__', '__setattr__', '__str__']
help() can be used in a similar way, but it gives all the docstrings recursively for the module, class, or method, or for the parent class of the attribute that was given as the argument.
A: Make sure that you are not importing something from within the awe directory structure. Due to some strange Python things concerning packages, this can lead to completely intractable error messages.
A: Sometimes problems arise because of old compiled Python files (*.pyc); there may be leftovers of Python files that no longer exist. Remove all these files and try again.
A: See the awe-prompt HOW-TO.
A: Queries in AWE are queries to the database from Python with the purpose of returning some needed information. The Queries HOW-TO containes a complete explaination of the use of queries in AWE.
A: The select() method is simply a convenience method to find the most recent, valid version of a given frame. Use the Python builtin help() on a particular select method to find out exactly how it makes this choice.
A: Generally speaking, all process parameters can be configured from the awe-prompt prior to running a make or executing a task. The Configuration HOW-TO gives a complete description of the various methods for process parameter configuration.
A: There are basically three ways to run SExtractor in the system. The most direct one would be to import `Sextractor' from `astro/external' and run `Sextractor.sex(image)'. You can also set the SExtractor configuration through this interface, and modify the list of output parameters. A second way to run SExtractor would be using the `sex' method of BaseFrame or children thereof. To be concrete, instantiate a ScienceFrame object and call the `sex' method. The third, and in our paradigm the most correct, way to run SExtractor, is to invoke the `make' method of a Catalog object. The frame you want to extract sources from is given as a dependency to the Catalog object. For the configuration of SExtractor and to modify its outputs, you need to provide the Catalog object with two additional dependencies: a SextractorConfig object, and a list of parameters. Note that this last way of creating a SExtractor catalog uses the first method. Also note, that the output of running SExtractor is in LDAC fits format.