source: trunk/python/linecatalog.py @ 1534

"""
A representation of a spectral line catalog.

Author: Malte Marquarding

"""
__revision__ = "$Revision: 1534 $"
from asap._asap import linecatalog as lcbase
from asap import rcParams
import os

class linecatalog(lcbase):
    """
    This class is a warpper for line catalogs. These can be either ASCII tables
    or the tables saved from this class.
    ASCII tables have the following restrictions:
    Comments can be present through lines starting with '#'.
    The first column contains the name of the Molecule. This can't contain spaces,
    if it does it has to be wrapped in ""
    The second column contains the frequency of the transition.
    The third column contains the error in frequency.
    The fourth column contains a value describing the intensity
    """

    def __init__(self, name):
        fpath = os.path.abspath(os.path.expandvars(os.path.expanduser(name)))
        if os.path.exists(fpath):
            lcbase.__init__(self, fpath)
        else:
            msg = "File '%s' not found" % fpath
            if rcParams['verbose']:
                print msg
                return
            else:
                raise IOError(msg)

    def __repr__(self):
        return lcbase.summary(self, -1)

    def summary(self):
        """
        Print the contents of the table.
        """
        try:
            from IPython.genutils import page as pager
        except ImportError:
            from pydoc import pager
        pager(lcbase.summary(self, -1))

    def set_name(self, name, mode="pattern"):
        """
        Set a name restriction on the table. This can be a standard unix-style
        pattern or a regular expression.
        Parameters:
            name:       the name patterrn/regex
            mode:       the matching mode, i.e. "pattern" (default) or "regex"
        """
        validmodes = "pattern regex".split()
        if not mode.lower() in validmodes:
            return
        lcbase.set_name(self, name, mode)

    def set_frequency_limits(self, fmin=1.0, fmax=120.0, unit="GHz"):
        """
        Set frequency limits on the table.
        Parameters:
            fmin:       the lower bound
            fmax:       the upper bound
            unit:       the frequency unit (default "GHz")

        Note:
            The underlying table conatins frequency values in MHz
        """
        base = { "GHz": 1000.0, "MHz": 1.0 }
        if not base.has_key(unit):
            raise ValueError("%s is not a valid unit." % unit)
        # the table conatins values in MHz
        lcbase.set_frequency_limits(self, fmin*base[unit], fmax*base[unit])

    def set_strength_limits(self, smin, smax):
        """
        Set line strength limits on the table (arbitrary units)
        Parameters:
            smin:       the lower bound
            smax:       the upper bound
        """
        lcbase.set_strength_limits(self, smin, smax)

    def save(self, name, overwrite=False):
        """
        Save the subset of the table to disk. This uses an internal data format
        and can be read in again.
        """
        name = os.path.expanduser(os.path.expandvars(name))
        if os.path.isfile(name) or os.path.isdir(name):
            if not overwrite:
                msg = "File %s exists." % name
                if rcParams['verbose']:
                    print msg
                    return
                else:
                    raise IOError(msg)
        lcbase.save(self, name)

    def reset(self):
        """
        Reset the table to its initial state, i.e. undo all calls to set_
        """
        lcbase.reset(self)

    def get_row(self, row=0):
        """
        Get the values in a specified row of the table.
        Parameters:
              row:        the row to retrieve
        """
        freq = lcbase.get_frequency(self, row)
        name = lcbase.get_name(self, row)
        return { 'name':name, 'value': freq }

    def __len__(self):
        return self.nrow()

    def __getitem__(self, k):
        if k < 0: k = self.nrow()-k
        return self.get_row(k)