NEW LEGEND -- create a geometry of a linear scale using color polygons

Name

NEW LEGEND -- create a geometry of a linear scale using color polygons

Author

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

Summary

	Name		NEW LEGEND	
	Type		mapper	
	Inputs		input_color_map	(colormap)
			Data Minimum	(float)
			Data Maximum	(float)
			Map Info	(string)
	Outputs		geom_output	(geometry)
	Parameters
			Name			Type	Def	Min	Max
			----			----	---	---	---
			Color Bins		(int)	 8	1	256
			Labels			(int)	 8	1	256
			X Scale			(float)	1.0	0.0	UNBOUND
			Y Scale			(float)	1.0	0.0	UNBOUND
			X Offset		(float) 0.0	0.0	UNBOUND
			Y Offset		(float) 0.0	0.0	UNBOUND
			Font Height		(float) 0.06	0.0	1.0
			Label Format		(string) "%7.3f"
			Border			(toggle)  0	0	1
			Number line		(toggle)  0	0	1
			Use Map Info		(toggle)  0	0	1
			Font			(int)	  0	0	21
			Legend Type		(choice) VERTICAL
			Vertical Label Position	(choice) RIGHT
			Horizontal Label Position (choice) ALTERNATING
			Line Red		(float) 1.0	0.0	1.0
			Line Green		(float) 1.0	0.0	1.0
			Line Blue		(float) 1.0	0.0	1.0
			Label Red		(float) 1.0	0.0	1.0
			Label Green		(float) 1.0	0.0	1.0
			Label Blue		(float) 1.0	0.0	1.0

Description

The NEW LEGEND module creates a color scale bar of linear bins in either
the horizontal or vertical with labeling controlled by C-language formats
to give the user more control than that found in the standard AVS "color
legend" module.
Color bins are selected from the input color map based upon linear increments
corresponding to the number of color bins selected.  For a typical Newton
AVS colormap, the lowest bin will be blue and the highest bin will be red.
The bins are labeled according to the Data Minimum and Data Maximum values
and the linear increments between.
In porting this module to the DEC ALPHA, integer colors did not work
properly, so compile-time "ifdef __alpha" statements are included to
signal that floating-point colors could be used.  The "__alpha" definition,
if present, is found in the standard AVS include file, port.h.

Inputs

input_color_map		standard AVS input color map
Data Minimum		minimum value for tile legend scale and linear bins
Data Maximum		maximum value for tile legend scale and linear bins
Map Info		string of values for initial settings for vertical
			legend (x offset, y offset, x scale, y scale) or
			horizontal legend (x offset, yoffset, xscale, yscale);
			parameters are passed from the ARCMAP module and are
			optionally used depending on the parameter toggle
			"Use Map Info"; this Map Info is useful if several
			different domains are viewed in the same geometry
			viewer window and default legend scale and offsets
			are needed for a variety of them

Outputs

geom_output		color tile output geometry with optional colored mesh

Parameters

Color Bins		number of color bins
Labels			number of labels (may be less than the number of bins) 
X Scale			width of each scale bar with 1.0 = one grid cell in
			width
Y Scale			height of each scale bar with 1.0 = one grid cell in
			height
X Offset		x coordinate position with reference to the data grid
			of the  lower left hand corner of the legend scale bar
Y Offset		y coordinate position with reference to the data grid
			of the lower left hand corner of the legend scale bar
Font Height		height of the labeling font in normalized coordinates
Label Format		C-language format in which each label is written
	
Border			switch indicating if a color border is requested around
			the length of the color scale bar
Number line		switch indicating if a number line is requested at each
			label position on the color scale bar
Use Map Info		switch indicating if the Map Info string passed from
			the ARCMAP module should be used to set legend
			parameters;  if this toggle is on, user selections
			for offset and scale are ignored
Font			AVS selected font for labels (range 1-21)
Legend Type		choice of VERTICAL or HORIZONTAL
Vertical Label
 Position		choice of RIGHT or LEFT
Horizontal Label
 Position 		choice of ALTERNATING, TOP, or BOTTOM
Line Red		red component of color for lines on and around color
			scale bar
Line Green		green component of color for lines on and around color
			scale bar
Line Blue		blue component of color for lines on and around color
			scale bar
Label Red		red component of color for labels for color scale bar
Label Green		green component of color for labels for color scale bar
Label Blue		blue component of color for labels for color scale bar

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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