************ Usage **************

visu-ncl -f infilename.nc [options] 

 -f infilename.nc   : Input file, mandatory

  This script is designed for longitude/latitude/pressure/time nc files.
  Required dimension names are: 
    Time indexes   : Time, time, time_counter
    Vertical levels: lev, presnivs
    Latitudes      : lat, latitude
    Longitudes     : lon, longitudes
    
== Options ==

[-h]                : This user manual

[-med media]        : media for output

  Default: x11
  Possible values:
     x11        => Display graph on screen
     ps,eps,pdf => Display graph in a ps,eps or pdf file

[-oname outputname] : name for the output

  Default: quickview (will be the name of the X11 window)
  The name extension (.ps, .eps, .pdf) is added automatically.

[-type typeplot]    : type of plot

  Default: coupe
  Possible values:
     coupe  => Display 1D graph or 2D contour plot
               You need to give at least 1 varying dimension, 
               otherwise default give only one point.
     ortho  => Display 2D orthographic projection
               You will be defaulted to a full lat/lon map.
     stereo => Display 2D stereographic projection
               You will be defaulted to a full lon map.

Options to define the plotted variable:
---------------------------------------

[-v varname]                     : Variable name for plot

  Default: liste => list the variables in file

  If varname = customvar then a user-defined variable can be plotted
  with -v customvar,labelvar
  This labelvar must be defined in the customVar routine in visu-utils.ncl

[-v2 varname]                    : Variable name to be overplotted

  Default: no second variable

[-tc ntcutmin[,ntcutmax[,tavg]]] : INDEXES for time slice (0 to <numberoftimepoints>-1)

  Default: ntcutmin=0 / ntcutmax=ntcutmin / tavg=ntcutmax
  ntcutmin=-999: average over all times
  tavg=-999    : average between ntcutmin and ntcutmax
  Known problem: on given files, the default has a problem. 
  In this case, try a time point different from 0, it should work.
  
[-pc pcutmin[,pcutmax[,pavg]]]   : VALUES for pressure slice

  Default: pcutmin=1.e4 / pcutmax=pcutmin / pavg=pcutmax
  pcutmin=-999 : average over all pressures
  pavg=-999    : average between pcutmin and pcutmax

[-lc lcutmin[,lcutmax[,lavg]]]   : VALUES for latitudinal slice

  Default: lcutmin=0 / lcutmax=lcutmin / lavg=lcutmax
  lcutmin=-999 : average over all latitudes
  lavg=-999    : average between lcutmin and lcutmax

[-Lc Lcutmin[,Lcutmax[,Lavg]]]   : VALUES for longitudinal slice

  Default: Lcutmin=0 / Lcutmax=Lcutmin / Lavg=Lcutmax
  Lcutmin=-999 : average over all longitudes
  Lavg=-999    : average between Lcutmin and Lcutmax

Cosmetic options for figure:
----------------------------

[-lim min,max[,step]] : limits for variable values

  Default: automatic
  1d     : min and max values for axis (step unused)
  2d     : min, max and step values for contours
  If only one value is given, back to default.

Cosmetic options for projections:
---------------------------------

[-center lon,lat] : longitude and latitude (degrees) of center point

  Default: 
  For orthographic: 0,40
  For stereographic: 0,90 (i.e. Northern Hemisphere)
  To plot Southern Hemisphere, ask for 0,-90 (any other will go back to default)
  If only one value is given, both are identical.
  
[-grid T/F]       : logical to plot the grid or not

  Default: T

[-gcol gridcol]   : color for the grid

  Default: white

[-gspc Dlon,Dlat] : intervals (degrees) for longitude and latitude lines

  Default: 30,20
  If only one value is given, both are identical.