This module allows users to extract data from AIRS AFS (AIRS Facility 
System) files.  The AIRS AFS format are refered to User's Guide For the Urban
Airshed Model, EPA-450/4-90-007D. Users may read through the very begining of 
the c codes provided to get an idea how the data is constructed.

	Input Data: Name of the AFS File   

	Output data: Field 1-D 3-Space 1-Vector IRREGULER
                    Which contains (x, y, z, value) of a point per record


        This module belongs to a group of modules submitted to the Inter-
national AVS Center for displaying points, lines and polygons over a map of the
United States. The group of the modules includes:

        AFSextract:             Extracting AFS Format Data
        AMSextract:             Extracting AMS Format Data
        LBFextract:             Extracting Link Base Mobile Data
        field_to_points:        Plot 3D points with color mapping
        field_to_lines:         Plot 3D lines with color mapping
        field_to_polygons:      Plot 3D polygons with color mapping
        getmap:                 Plot political boundary of states and
                                countys in the United State
        geomreset:              Reset and normalize the geometry viewer
                                automatically
        zoomer:                 A driver to allow zoom in and out to a
                                particular geographical area
        resetlegend:            To reset the position and size of ithe color
                                legend if used
        minmax:                 To find out the min and max value of a field


        An example network is shown below:


                                AFSextract
                                   |
                                write field


	Contact person: Jeff Wang, MCNC/NCSC, (919)-248-9242