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- SDSS Utilities (`pydl.pydlutils`) »
- chunks

# chunks

class pydl.pydlutils.spheregroup.chunks(ra, dec, minSize)

  Bases: `object`

  chunks class

  Functions for creating and manipulating spherical chunks are implemented as methods on this class.

  Init creates an object whose attributes are similar those created by the setchunks() function in the spheregroup library.

  Methods Summary

  `assign`(ra, dec, marginSize) | Take the objects and the chunks (already defined in the constructor) and assign the objects to the appropriate chunks, with some leeway given by the parameter marginSize.
  `chunkfriendsoffriends`(ra, dec, chunkList, ...) | Does friends-of-friends on the ra, dec that are defined by chunkList.
  `cosDecMin`(i) | Frequently used utility function.
  `friendsoffriends`(ra, dec, linkSep) | Friends-of-friends using chunked data.
  `get`(ra, dec) | Find the chunk to which a given point belongs.
  `getbounds`(ra, dec, marginSize) | Find the set of chunks a point (with margin) belongs to.
  `getraminmax`(ra, raOffset) | Utility function used by rarange.
  `rarange`(ra, minSize) | Finds the offset which yields the smallest raRange & returns both.

  Methods Documentation

  assign(ra, dec, marginSize)

    Take the objects and the chunks (already defined in the constructor) and assign the objects to the appropriate chunks, with some leeway given by the parameter marginSize. Basically, at the end, each chunk should be associated with a list of the objects that belong to it.

  chunkfriendsoffriends(ra, dec, chunkList, linkSep)

    Does friends-of-friends on the ra, dec that are defined by chunkList.

  cosDecMin(i)

    Frequently used utility function.

  friendsoffriends(ra, dec, linkSep)

    Friends-of-friends using chunked data.

  get(ra, dec)

    Find the chunk to which a given point belongs.

  getbounds(ra, dec, marginSize)

    Find the set of chunks a point (with margin) belongs to.

  getraminmax(ra, raOffset)

    Utility function used by rarange.

  rarange(ra, minSize)

    Finds the offset which yields the smallest raRange & returns both.

    Notes

    Warning

    This is not (yet) well-defined for the case of only one point.