gnomview


This IDL facility provides a means to visualise a Gnomonic projection (radial projection onto a tangent plane) of HEALPix and COBE Quad-Cube maps in an IDL environment. It also offers the possibility to generate gif and postscript images of the projected map.


Location in HEALPix directory tree: src/idl/visu/gnomview.pro


FORMAT

IDL> GNOMVIEW, File, [Select, ] [COLT=, ... ... UNITS=, XPOS=, YPOS= ]


QUALIFIERS


For a full list of qualifiers see mollview


KEYWORDS


For a full list of keywords see mollview


DESCRIPTION


gnomview reads in a HEALPix sky map in FITS format and generates a Gnomonic projection of it, that can be visualized on the screen or exported in a GIF, PNG, Postscript or FITS file. gnomview allows the selection of the coordinate system, point of projection, map size, color table, color bar inclusion, linear or log scaling, histogram equalised color scaling, maximum and minimum range for the plot, plot-title etc. It also allows the representation of the polarization field.


RELATED ROUTINES

This section lists the routines related to gnomview


see mollview


EXAMPLE:

gnomview, `planck100GHZ-LFI.fits', rot=[160,-30], reso_arcmin=2., $
  pxsize = 500., title='Simulated Planck LFI Sky Map at 100GHz'

gnomview reads in the map ` planck100GHZ-LFI.fits' and generates an output image of the size of 500×500 screen pixels, with a resolution of 2 arcmin/screen pixel at the center. The temperature scale has been set to lie between ± 100 ($ \mu$K), and the title ` Simulated Planck LFI Sky Map at 100GHz' has been appended to the image. The map is centered at (l =160, b =-30)


EXAMPLE:

map

= findgen(48)
triangle = create_struct('coord','G','ra',[0,80,0],'dec',[40,45,65])
gnomview, map,/online,res=25,graticule=[45,30],rot=[10,20,30],$
  title='Gnomic projection',subtitle='gnomview', $
  outline=triangle

makes a gnomic projection of map (see Figure 1b on page [*]) after an arbitrary rotation, with a graticule grid (with a 45o step in longitude and 30o in latitude) and an arbitrary triangular outline

Eric Hivon 2003-02-07