Source code for lsst.sims.maf.slicers.moSlicer

import numpy as np
import pandas as pd

from .baseSlicer import BaseSlicer
from lsst.sims.maf.plots.moPlotters import MetricVsH, MetricVsOrbit

from .orbits import Orbits

__all__ = ['MoObjSlicer']


[docs]class MoObjSlicer(BaseSlicer): """ Slice moving object _observations_, per object and optionally clone/per H value. Iteration over the MoObjSlicer will go as: * iterate over each orbit; * if Hrange is not None, for each orbit, iterate over Hrange. Parameters ---------- Hrange : numpy.ndarray or None The H values to clone the orbital parameters over. If Hrange is None, will not clone orbits. """ def __init__(self, Hrange=None, verbose=True, badval=0): super(MoObjSlicer, self).__init__(verbose=verbose, badval=badval) self.Hrange = Hrange self.slicer_init = {'Hrange': Hrange, 'badval': badval} # Set default plotFuncs. self.plotFuncs = [MetricVsH(), MetricVsOrbit(xaxis='q', yaxis='e'), MetricVsOrbit(xaxis='q', yaxis='inc')]
[docs] def setupSlicer(self, orbitFile, delim=None, skiprows=None, obsFile=None): """Set up the slicer and read orbitFile and obsFile from disk. Sets self.orbits (with orbit parameters), self.allObs, and self.obs self.orbitFile and self.obsFile Parameters ---------- orbitFile : str The file containing the orbit information. This is necessary, in order to be able to generate plots. obsFile : str, optional The file containing the observations of each object, optional. If not provided (default, None), then the slicer will not be able to 'slice', but can still plot. """ self.readOrbits(orbitFile, delim=delim, skiprows=skiprows) if obsFile is not None: self.readObs(obsFile) else: self.obsFile = None self.allObs = None self.obs = None # Add these filenames to the slicer init values, to preserve in output files. self.slicer_init['orbitFile'] = self.orbitFile self.slicer_init['obsFile'] = self.obsFile
[docs] def readOrbits(self, orbitFile, delim=None, skiprows=None): # Use sims_movingObjects to read orbit files. orb = Orbits() orb.readOrbits(orbitFile, delim=delim, skiprows=skiprows) self.orbitFile = orbitFile self.orbits = orb.orbits # Then go on as previously. Need to refactor this into 'setupSlicer' style. self.nSso = len(self.orbits) self.slicePoints = {} self.slicePoints['orbits'] = self.orbits # And set the slicer shape/size. if self.Hrange is not None: self.shape = [self.nSso, len(self.Hrange)] self.slicePoints['H'] = self.Hrange else: self.shape = [self.nSso, 1] self.slicePoints['H'] = self.orbits['H'] # Set the rest of the slicePoint information once self.nslice = self.shape[0] * self.shape[1]
[docs] def readObs(self, obsFile): """Read observations of the solar system objects (such as created by sims_movingObjects). Parameters ---------- obsFile: str The file containing the observation information. """ # For now, just read all the observations (should be able to chunk this though). self.allObs = pd.read_csv(obsFile, delim_whitespace=True, comment='#') self.obsFile = obsFile # We may have to rename the first column from '#objId' to 'objId'. if self.allObs.columns.values[0].startswith('#'): newcols = self.allObs.columns.values newcols[0] = newcols[0].replace('#', '') self.allObs.columns = newcols if 'velocity' not in self.allObs.columns.values: self.allObs['velocity'] = np.sqrt(self.allObs['dradt']**2 + self.allObs['ddecdt']**2) if 'visitExpTime' not in self.allObs.columns.values: self.allObs['visitExpTime'] = np.zeros(len(self.allObs['objId']), float) + 30.0 # If we created intermediate data products by pandas, we may have an inadvertent 'index' # column. Since this creates problems later, drop it here. if 'index' in self.allObs.columns.values: self.allObs.drop('index', axis=1, inplace=True) self.subsetObs()
[docs] def subsetObs(self, pandasConstraint=None): """ Choose a subset of all the observations, such as those in a particular time period. """ if pandasConstraint is None: self.obs = self.allObs else: self.obs = self.allObs.query(pandasConstraint)
def _sliceObs(self, idx): """Return the observations of a given ssoId. For now this works for any ssoId; in the future, this might only work as ssoId is progressively iterated through the series of ssoIds (so we can 'chunk' the reading). Parameters ---------- idx : integer The integer index of the particular SSO in the orbits dataframe. """ # Find the matching orbit. orb = self.orbits.iloc[idx] # Find the matching observations. if self.obs['objId'].dtype == 'object': obs = self.obs.query('objId == "%s"' %(orb['objId'])) else: obs = self.obs.query('objId == %d' %(orb['objId'])) # Return the values for H to consider for metric. if self.Hrange is not None: Hvals = self.Hrange else: Hvals = np.array([orb['H']], float) # Note that ssoObs / obs is a recarray not Dataframe! # But that the orbit IS a Dataframe. return {'obs': obs.to_records(), 'orbit': orb, 'Hvals': Hvals}
[docs] def __iter__(self): """ Iterate through each of the ssoIds. """ self.idx = 0 return self
[docs] def __next__(self): """ Returns result of self._getObs when iterating over moSlicer. """ if self.idx >= self.nSso: raise StopIteration idx = self.idx self.idx += 1 return self._sliceObs(idx)
def __getitem__(self, idx): # This may not be guaranteed to work if/when we implement chunking of the obsfile. return self._sliceObs(idx)
[docs] def __eq__(self, otherSlicer): """ Evaluate if two slicers are equal. """ result = False if isinstance(otherSlicer, MoObjSlicer): if otherSlicer.orbitFile == self.orbitFile: if otherSlicer.obsFile == self.obsFile: if np.all(otherSlicer.slicePoints['H'] == self.slicePoints['H']): result = True return result