DOWNLOADING NCL: The most current version of NCL can be downloaded from:

	http://ngwww.ucar.edu/ncl/download.html

	The current version is: NCAR Command Language Version 4.2.0.a032
	(Release December 6, 2004)
	This version of WRF_NCL needs at least NCL version 4.2.0.a032
	to run sucessfully.

NCL Documentation links:

	The main reference guide for NCL is:

		http://www.ncl.ucar.edu/index.shtml

	Main list of NCL functions and procedures including math and graphics
	functions:
		
		http://www.ncl.ucar.edu/Document/index.shtml

	"Getting Started Using NCL" (GSUN) documentation is:

		http://www.ncl.ucar.edu/Document/Manuals/Getting_Started/

		

IMPORTANT: 
	Before running the script make sure you have the .hluresfile
	in the correct directory. 
	In the WRF_NCL directory a file DOThluresfile is supplied.
		copy this file to   ~/.hluresfile
	For more information about this file see:
		http://www.ncl.ucar.edu/Document/Graphics/hlures.shtml

	Before running any of the examples edit the file and change the 
	path in addfiles call to point to your WRF data file.


If you are going to construct or change the scripts, then...

CONTENTS:

In the WRF_NCL directory are the files:
	WRFOptions.ncl			! Setting basic plotting option
	WRFPlot.ncl			! Contain plotting functions and procedures
	WRFUserARW.ncl			! Contain diagnostic
The files must be loaded in to NCL using the load command in order to use
any of the functions described below.

NOTE:

Many of the functions for creating plots accept optional arguments. Some
of these optional arguments are defined only for those functions and will
not work for every function. There are lists of these options with each
function description. Additionally actual HLU plot resources can be passed
as optional arguments. These resources are defined in the HLU reference
pages : http://www.ncl.ucar.edu/Document/HLUs/                

For ContourPlot options:
http://www.ncl.ucar.edu/Document/Graphics/Resources/cn.shtml   

For VectorPlot options:
http://www.ncl.ucar.edu/Document/Graphics/Resources/vc.shtml   

For MapPlot options:
http://www.ncl.ucar.edu/Document/Graphics/Resources/mp.shtml

OPTIONAL ARGUMENTS:
Normally an optional argument is created by setting:
	opts = True
To allow a user to pass general options to plotting functions, this
has been set in the "WRFOptions.ncl" script, so in this case a user 
needs to create optional arguments by setting:
	opts = res

Other options that is recognized:
	HEADER INFORMATION
		MainTile and TimeLabel is set at top of script
		Placement on plot controlled by WRFOptions.ncl
		Others are mostly optional setting - is not
		set the information will be obtained from netCDF file
		If a field is changed (i.e., temp field plotted in F),
		these options must be used to overwrite netCDF values
	@MainTitle	! Main title plotted at top of each plot
	@TimeLabel	! Initial time plotted at top 
	@FieldTitle	! Default is to get this information from the 
			! netCDF file, but it can be overwritten
	@SubFieldTitle	! Secondary field - i.e., for tendencies
	@UnitLabel	! Default is to get this information from the 
                               ! netCDF file, but it can be overwritten
	@PlotLevelID	! Plot level of the plot


	PLOT SIZE
	@vpWidthF ; @vpHeightF	! Default is a "nice" plot
				! or set these to overwrite the default
	@AspectRatio		! Plot sixe can also be controlled with this option


	PLOT CONTOURS
		Optional - plot will create "nice" values if not set
		If default needs to be overwritten, use either 
			ContourParameters  OR
			cnLevelSelectionMode + cnLevels + cnFillColors
	@ContourParameters	!  / x / plot every x 
				! / x, y, a / plot from x to y every a

	@cnLevelSelectionMode	! Set explicit levels
	@cnLevels		! Which levels
	@cnFillColors		! Color for each level

	
	CONTOUR / SHADED PLOTS
		Default is contour
		If shaded is set to True, contour are automatically
		turned off, if not explicitly set
	@cnFillOn	! Set to True for shaded plots (False is default)
	@cnLinesOn	! Used if both contour and shaded plots are required
	@cnLineColor	! Line color - default is Black
	@cnHighLabelsOn ! Set High/Low values on - default is False
		@cnLowLabelsOn	
	@cnInfoLabelOn	! For contour plots, add interval information below plot
			! Default is False if cnLinesOn is True
	@cnLineLabelsOn	! Set labes on lines. Default True if cnFillOn False
	@cnLineLabelBackgroundColor	! Background color of line label 
					! -1 is transparent
	@cnConstFLabelOn	! If contant plot possible, set to False to stop
				! contant lable being printed


	VECTOR PLOTS
	@NumVectors	! Number of vectors on plot
	@vcGlyphStyle	! Default is WindBard, also take "LineArrow"


	CROSS SECTION PLOTS
	@PlotOrientation	! Used for X-section plots


LIST OF FUNCTIONS AND OPTIONAL ARGUMENTS:


function wrf_contour(
	nc_file:file,
	wks[1]: graphic, 
	data[*][*]:numeric,
	opt_args[1]:logical)

	Creates a new contour plot (for both shaded and line countours).
	This function does not display the plot, only creates it.

        Args:
                nc_file:   netCDF file being processed            
                wks:       Workstation                           
                data:      Data to contour, must not be constant and must be 2D   
                opt_args:  Optional arguments


function wrf_vector(
	nc_file:file,
	wks[1]: graphic, 
	data_u[*][*]:numeric,
	data_v[*][*]:numeric, 
	opt_args[1]:logical)

	Creates a new vector plot.
	This function does not display the plot, only creates it.

        Args:
                nc_file:   netCDF file being processed            
                wks:       Workstation                           
                data_u: horizontal vector component must be same dimensions as
                        data_v
                data_v: vetical vector component
                opt_args:  Optional arguments


function wrf_map(
	wks[1]:graphic,
	in_file[1]:file,
	opt_args[1]:logical)

	Use this to create a map object based on the map information available
	in a wrf netCDF file.

	Args:
		wks : Workstation
		in_file: the in which wrf map information is described
		opt_args: supports resources for the map object


procedure wrf_map_overlay(
	wks:graphic,
	base[1]:graphic,
	plots[*]:graphic, 
	opt_arg[1]:logical)

	Used to overplay plots created with wrf_contour/wrf_vector over a map background

	Args:
		wks : Workstation
		base : basic map background
		plots : all the plots that need to be overlayed over the map background
		opt_args : Optional arguments

procedure wrf_overlay(
	wks:graphic,
	plots[*]:graphic, 
	opt_arg[1]:logical)

	Used to overplay plots created with wrf_contour/wrf_vector

	Args:
		wks : Workstation
		plots : all the plots that need to be overlayed 
		opt_args : Optional arguments


procedure print_opts(
	opts_name,
	opts,
	debug)

	Procedure used for debugging

procedure print_header(
	icount:integer,
	debug)

	Procedure used for debugging