NAME	NEW CROP -- crop 3d or 4d field to reduce the range of any of its
			dimensions   

AUTHOR	Kathy Pearson, MCNC, kathyp@mcnc.org, (919) 248-9240

SUMMARY

	Name		NEW CROP	

	Type		mapper	

	Inputs		input field		(field)	
			input X-Y map parameters(string)

	Outputs
			output field		(field)
			output string		(string)

	Parameters
			Name			Type	Def	Min	Max
			----			----	---	---	---
			xmin			(int)	-5000	-5000	5000
			xmax			(int)	-5000	-5000	5000
			ymin			(int)	-5000	-5000	5000
			ymax			(int)	-5000	-5000	5000
			zmin			(int)	-5000	-5000	5000
			zmax			(int)	-5000	-5000	5000
			tmin			(int)	-5000	-5000	5000
			tmax			(int)	-5000	-5000	5000
			crop method		(choice) USER CHOICE
			reset field minmax	(toggle)    0       0      1
			crop limit to 2		(toggle)    0       0      1
	

DESCRIPTION

Unlike the standard AVS crop module, the NEW CROP module allows the user to
crop a field down to a single grid cell in any dimension.  For compatibility
with the AVS field-to-mesh module, the "crop limit to 2" should be set since
it, like all standard AVS modules, cannot correctly deal with a dimension of
one unless it is the last dimension.  Also unlike the standard crop module,
the NEW CROP module values will "hold" between invocations if the previous
settings are within the latest range for X, Y, Z, or Time.  The standard crop
module allows cropping on 3 dimensions only, but the NEW CROP module allows
the user to crop either 3D or 4D fields.

INPUTS

input field	field	

input X-Y map
 parameters	a string passed from the GET MODEL MAP module with cropping
		information based upon a map description file that includes
		settings for the entire grid, the grid without boundary 
		conditions, and an arbitrary specially defined clipped region;
		these values are not used if USER CHOICE crop selection is
		set

OUTPUTS

output field	the cropped field 

output string	a string specifying ranges for X, Y, Z, and Time

PARAMETERS

xmin		the minimum value in the X dimension

xmax		the maximum value in the X dimension

ymin		the minimum value in the Y dimension

ymax		the maximum value in the Y dimension

zmin		the minimum value in the Z dimension

zmax		the maximum value in the Z dimension

tmin		the minimum value in the Time dimension

tmax		the maximum value in the Time dimension

crop method	selection of default map crops (DOMAIN GRID,
			 DOMAIN CLIPPED GRID, DOMAIN BOUNDARY) or
			 USER CHOICE whereby any X Y Z Time values
			 within the range of the current input field
			 may be cropped to dimensions of user choice
			 (including a dimension of 1) 

reset field
 minmax		toggle indicating if AVS routine should be called to reset
		the minmax values after the cropping is done

crop limit
 to 2		toggle indicating if module is used in a network with
		standard AVS field-to-mesh modules or other AVS modules
		requiring dimensions to be at least 2; for MCNC-written
		NEW TILE modules, the toggle should be off since single
		dimensions are allowed for them 

EXAMPLE

RELATED MODULES

LIMITATIONS

SEE ALSO

(MCNC Visualization Plan)						11/93
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The MCNC Environmental Programs Group has created this module as part of a
suite of AVS demo modules, networks, and sample data sets to demonstrate 
the functionality of its visualization prototype for an Environmental 
Decision Support System (EDSS).  This system provides a unified method of 
analysis and visualization for data output from different environmental air 
quality models.  Remotely, standard output files from the following models 
can be read into AVS:

        ROM (Regional Oxidant Model)
        RADM (Regional Acid Deposition Model), low res and high res
        RADM (Regional Acid Depostion Model) Emissions, low res
        UAM (Urban Airshed Model, regulatory version)
        UAM (Urban Airshed Model, AREAL research version)
        UAM Wind (Urban Airshed Model, regulatory version)
        MCNC ALPHA-Prototype netCDF files

Alternatively, xdr portable binary AVS fields can be created from these
data types and accessed directly from the local workstation.

You can download these modules individually from the IAC using anonymous
ftp to the appropriate directories /avs_modules at avs.ncsc.org.  
If you would like to download the entire suite of modules, networks, and
sample datasets at the same time, the IAC recommends that you use 
anonymous ftp to grab the following file from avs.ncsc.org -

/sample_data/avs_data/MCNC_Env_Pgms/MCNC_Env_Pgms.tar.Z

This contains all source code to all local and remote modules, as well as
all of the sample datasets, networks, documentation, installation, and
usage notes.
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