
    BASIC TEST

    This test will test file-creation and file-reading.  It will create
    a simple time independent gridded file "LL_2D" using M3Tools
    program "latlon" and then will report on its statistics using
    "m3stat".

    M3Tools program "latlon" is a standard command-line driven tool  for
    creating time independent GRIDDED and/or BOUNDARY files containing
    latitudes and longitudes for a specified I/O API grid. It is
    controlled by various environment variables and a "GRIDDESC" file,
    which contains sets of definitions for multiple coordinate systems
    and grids in human readable/editable ASCII format. The sample
    GRIDDESC file for this test contains a selection of Lat-Lon,
    Lambert, and UTM coordinate systems and grids, including the grid
    "LL_Terrain" for high resolution (30 arc-second) CONUS MM5/WRF
    terrain, the  "BELD3_US_1KM" high resolution BELD biogenics grid,
    and a pair of sample grids covering North Carolina.
    Environment variable IOAPI_ISPH specifies that the (default) MM5/WRF
    perfect sphere is used as the spheroid for the coordinate
    computations.
    
    M3Tools program "m3stat" is a standard command-line driven tool that
    reads I/O API files and computes statistics (max and its location,
    min and its location, mean, and standard deviation) for a
    user-specified GRIDDED, BOUNDARY, CUSTOM, IDDATA, or SPARSE-MATRIX
    Models-3 file and list of variables within it.

    See
    <https://cjcoats.github.io/ioapi/GRIDDESC.html>
    <https://cjcoats.github.io/ioapi/LATLON.html>
    <https://cjcoats.github.io/ioapi/M3STAT.html>
    <https://cjcoats.github.io/ioapi/SETSPHERE.html>

    The  "latlon" output file can be found as "LL_2D.NC45KM_LAM_9x7.nc"
    in the tests output-directory.  This file contains four output
    variables:
    LAT:  ISO-Standard ;709 cell-center latitudes  as REAL
    LON:  ISO-Standard 6709 cell-center longitudes as REAL
    LATD: ISO-Standard 6709 cell-center latitudes  as REAL*8
    LOND: ISO-Standard 6709 cell-center longitudes as REAL*8
    
    In this case, the "m3stat" output statistics-report will be written
    to a file, which can be found as "LL_2D.NC45KM_LAM_9x7.stats" in the
    test output-directory,
