/**
@page hippoplotter The hippoplotter.py module

Here is a summary of the classes and functions available in this module.

- <tt>newNTuple(arrays, labels, name="", register=1)</tt>\n Define and
  register a new hippo n-tuple. @c arrays is a tuple or list of
  numeric sequences (all the same length), and @c labels is a tuple or
  list of the labels to be applied to each sequence.

- <tt>addNTuple(nt, key="")</tt>\n Add an existing hippo n-tuple to
  hippoplotter's internal list.
  
- <tt>getDisplay()</tt>\n Returns the handle to the selected display.

- <tt>getDisplays()</tt>\n Returns a tuple of handles to all of the
  displays on the canvas.

Each of the plotting functions can use either the hippo n-tuple or be
passed sequences as arguments.  The former type of functions has
capitalization appropriate for proper names.  For example,

- <tt>Histogram(nt, xname, xlog=0, ylog=0, 
                xrange=(), yrange=(), title="",
                pointRep="Column", oplot=0, color=None)</tt>\n 
  Create a histogram of the values in the @c xname column of the n-tuple @c nt.
    
- <tt>histogram(x, xname='x', xlog=0, ylog=0, 
                xrange=(), yrange=(), title="",
                pointRep="Column", oplot=0, color=None)</tt>\n 
   Create a histogram of the values in @c x, which can be any kind of
   sequence (e.g., tuple, list, or flat numarray) of floats or
   integers.

Hereafter, we give only the signature and descriptions, when
necessary, of the n-tuple versions of these plotting functions:

- <tt>YPlot(nt, yname, xlog=0, ylog=0, xrange=(), yrange=(),
            title="", pointRep="Symbol", oplot=0, color=None)</tt>

- <tt>Scatter(nt, xname, yname, xlog=0, ylog=0, xrange=(), yrange=(), 
              title="", pointRep="Symbol", oplot=0, color=None)</tt>

- <tt>XYPlot(nt, xname, yname, xerr=None, yerr=None, xlog=0, ylog=0,
             xrange=(), yrange=(), title="", pointRep="Symbol", oplot=0,
             color=None)</tt>

- <tt>StripChart(nt, xname, yname, xlog=0, ylog=0, xrange=(), yrange=(), 
                title="", pointRep="Line", oplot=0, color=None)</tt>

- <tt>Profile(nt, xname, yname, xlog=0, ylog=0, xrange=(), yrange=(),
              pointRep="Symbol", title="", oplot=0, color=None)</tt>

- <tt>XYHist(nt, xname, yname, xbinsize=0, ybinsize=0,
            xrange=(), yrange=(), xlog=0, ylog=0, Aitoff=0, title="",
            pointRep="ColorBox", oplot=0)</tt>\n
   HippoDraw's Color Plot.

- <tt>Contour(nt, xname, yname, xbinsize=0, ybinsize=0,
             xrange=(), yrange=(), xlog=0, ylog=0, Aitoff=0, title="",
             pointRep="Contour", oplot=0)</tt>

- <tt>Image(nt, zlog=0, aspect=0, transform=None, title="")</tt>\n
  HippoDraw's Z Plot, assuming @c nt has only one column.

- <tt>fitsImage(fits_image, zlog=0, aspect=0, transform=None, title="")</tt>\n
  Create an image display using @c Image, reading the data from the
  FITS file @c fits_image.  @c fits_image can also be a @c FitsImage
  object.

- <tt>class FitsImage(file)</tt>\n 
  @c file is the filename of a FITS image file.  This is a thin wrapper
  to a pyfits object, providing a single column hippo n-tuple of the
  image data and a method, @c getKeyVal, to access the primary image
  keyword values.

- <tt>FitsNTuple(fitsFiles, extension=1, name="")</tt>\n
  This wraps the <tt>FitsNTuple.FitsNTuple</tt> class, which reads in
  FITS files and creates a hippo n-tuple of the FITS columns and a @c
  FitsNTuple object that has numarrays of each FITS column as
  attributes.  @c fitsFiles can either be the filename of a single
  FITS file or a tuple or list of FITS files, all having the same
  format.

- <tt>class StaticHist(xrange=(-1, 1), xBinWidth = 0.1, title="", xlabel="",
                       color=None)</tt>\n
  This class wraps HippoDraw's Static Histogram display and delegates
  directly to the filling methods of the Static Histogram objects.

- <tt>class Static2DHist(xrange=(-1, 1), yrange=(-1, 1),
                         xBinWidth=0.1, yBinWidth=0.1,
                         title="", xlabel="", ylabel="")</tt>\n
  This class wraps HippoDraw's Static 2D Histogram class.

- <tt>setCut()</tt>\n
  This function allows the user to set the cut boundaries by right
  clicking at the end points of the range on a Cut display.  To exit
  the @c setCut mode, the user must click on an empty part of the
  canvas.

- <tt>dragCut()</tt>\n
  This allows the user to set the center of an existing cut by right
  clicking on a Cut display.  

- <tt>resize(restore=None)</tt>\n
  This function allows the user to set the plot limits by right
  clicking on opposite corners of the rectangular region defining the
  new plot limits.  If a non-<tt>None</tt> @c restore argument is provided,
  then right clicking a display will restore its plot limits to the
  values it had when the display was created.

- <tt>fitData(display, funcName)</tt>\n 
  This will apply and fit a hippo function, e.g., <tt>"PowerLaw"</tt>,
  to the dataRep in the specified display.  It returns a tuple of
  dictionaries of parameter values and error estimates and the handle
  to the function itself:
  @verbatim
  >>> (params, errors, func) = fitData(display, "PowerLaw")
  >>> print "%.2e +/- %.2e" % (params["Index"], errors["Index"])
  -1.78e+00 +/- 5.93e-03
  @endverbatim

- <tt>slopes()</tt>\n 
  This allows the user to estimate slopes, exponential scales, or
  power-law indices of displayed data without having to go through the
  fitter.  Right clicking at two points on a display will cause a
  straight line to be drawn connecting the points; the slope, scale
  factor, or power-law index appropriate for that line will be printed,
  depending on whether the axes are both linear, log-linear, or
  log-log, respectively.  This mode is exited by clicking on an empty
  part of the canvas.

- <tt>hline(y=None)</tt>\n
  This will draw a horizontal line on the selected display at @c y, if
  it is given. If @c y is not given, then the line will be drawn at the
  location given by a right-click on any display.

- <tt>vline(x=None)</tt>\n
  See @c hline.

- <tt>pickData()</tt>\n 
  This allows the user to pick data values from a display by right
  clicking.  The locations are printed, and a hippo n-tuple containing
  the pick data is returned.  Once a display is selected by the
  initial right-click, only pick data from that display is extracted.
  Clicking on an empty portion of the canvas exits from the @c
  pickData mode.

- <tt>clear()</tt>\n
  This clears all displays from the canvas.

- <tt>prompt(prompt=None)</tt>\n
  Useful for writing interactive scripts, this prompts the user for input.

- <tt>setParam(target, value, func)</tt>\n
  This wraps the @c setParameters method of hippo function objects and
  allows a single parameter to be set:
  @verbatim
  >>> setParam("Index", -2.1, pl)
  @endverbatim

- <tt>setFixed(targets, func)</tt>\n
  This wraps the @c setFixedFlags method of hippo function objects, allowing
  the user to pass a tuple of parameter names that he/she wishes to fix:
  @verbatim
  >>> setFixed(("Prefactor", "Index"), pl)
  @endverbatim
*/