def plotCoordinateTransformationOnSky(transformation, outfile=None, myProjection='hammer',
    noTitle=False, noLabels=False, returnPlotObject=False):
    """
    Produce a sky-plot in a given coordinate system with the meridians and paralles for another
    coordinate system overlayed. The coordinate systems are specified through the
    pygaia.coordinates.Transformations enum. For example for Transformations.GAL2ECL the sky plot will be
    in Ecliptic coordinates with the Galactic coordinate grid overlayed.

    Keywords
    --------

    transformation - The coordinate transformation for which to make the plot (e.g.,
                     Transformations.GAL2ECL)
    outfile        - Save plot to this output file (default is to plot on screen). Make sure an extension
                     (.pdf, .png, etc) is included.
    myProjection   - Use this map projection (default is 'hammer', see basemap documentation)
    noTitle        - If true do not include the plot title.
    noLabels       - If true do not include plot labels.
    returnPlotObject - If true return the matplotlib object used for plotting. Further plot elements can
                       then be added.
    """
    ct = CoordinateTransformation(transformation)

    parallels=arange(-80.0,90.0,10.0)
    meridians=arange(0.0,375.0,15.0)
    meridianMax=degreesToRadians(85.0)
    parallelsMax=degreesToRadians(179.0)

    fig=plt.figure(figsize=(12,6))
    basemapInstance=Basemap(projection=myProjection,lon_0=0, celestial=True)
    basemapInstance.drawmapboundary()

    for thetaDeg in parallels:
      phi=linspace(-pi,pi,1001)
      theta=zeros_like(phi)+degreesToRadians(thetaDeg)
      phirot, thetarot = ct.transformSkyCoordinates(phi, theta)
      x ,y = basemapInstance(radiansToDegrees(phirot), radiansToDegrees(thetarot))
      
      indices=(phirot>=0.0)
      xplot=x[indices]
      yplot=y[indices]
      if any(indices):
        xplot, yplot = _orderGridlinePoints(xplot, yplot)
      plt.plot(xplot,yplot,'b-')
     
      indices=(phirot<0.0)
      xplot=x[indices]
      yplot=y[indices]
      if any(indices):
        xplot, yplot = _orderGridlinePoints(xplot, yplot)
      plt.plot(xplot,yplot,'b-')

    for phiDeg in meridians:
      theta=linspace(-meridianMax,meridianMax,1001)
      phi=zeros_like(theta)+degreesToRadians(phiDeg)
      phirot, thetarot = ct.transformSkyCoordinates(phi, theta)
      x ,y = basemapInstance(radiansToDegrees(phirot), radiansToDegrees(thetarot))

      indices=(phirot>=0.0)
      xplot=x[indices]
      yplot=y[indices]
      if any(indices):
        xplot, yplot = _orderGridlinePoints(xplot, yplot)
      plt.plot(xplot,yplot,'b-')
     
      indices=(phirot<0.0)
      xplot=x[indices]
      yplot=y[indices]
      if any(indices):
        xplot, yplot = _orderGridlinePoints(xplot, yplot)
      plt.plot(xplot,yplot,'b-')

    if (not noTitle):
      plt.title("Sky projection in " + ct.transformationStrings[1] + " coordinates with the corresponding " + ct.transformationStrings[0] + " grid overlayed")

    if (not noLabels):
      for theta in arange(-60,90,30):
        phirot, thetarot=ct.transformSkyCoordinates(0.0,degreesToRadians(theta))
        x, y = basemapInstance(radiansToDegrees(phirot), radiansToDegrees(thetarot))
        plt.text(x,y,"${0}$".format(theta),fontsize=16,va='bottom',ha='center',color='r')
      for phi in arange(-180,0,30):
        phirot, thetarot=ct.transformSkyCoordinates(degreesToRadians(phi),0.0)
        x, y = basemapInstance(radiansToDegrees(phirot), radiansToDegrees(thetarot))
        plt.text(x,y,"${0}$".format(phi),fontsize=16,va='bottom',ha='center',color='r')
      for phi in arange(30,180,30):
        phirot, thetarot=ct.transformSkyCoordinates(degreesToRadians(phi),0.0)
        x, y = basemapInstance(radiansToDegrees(phirot), radiansToDegrees(thetarot))
        plt.text(x,y,"${0}$".format(phi),fontsize=16,va='bottom',ha='center',color='r')

    if (outfile != None):
      plt.savefig(outfile)
    elif (returnPlotObject):
      return plt.gca(), basemapInstance
    else:
      plt.show()
Produce a sky-plot in a given coordinate system with the meridians and paralles for another
    coordinate system overlayed. The coordinate systems are specified through the
    pygaia.coordinates.Transformations enum. For example for Transformations.GAL2ECL the sky plot will be
    in Ecliptic coordinates with the Galactic coordinate grid overlayed.

    Keywords
    --------

    transformation - The coordinate transformation for which to make the plot (e.g.,
                     Transformations.GAL2ECL)
    outfile        - Save plot to this output file (default is to plot on screen). Make sure an extension
                     (.pdf, .png, etc) is included.
    myProjection   - Use this map projection (default is 'hammer', see basemap documentation)
    noTitle        - If true do not include the plot title.
    noLabels       - If true do not include plot labels.
    returnPlotObject - If true return the matplotlib object used for plotting. Further plot elements can
                       then be added.