s.what script

[Simon Cox]

At 6:02 PM 28/3/96, Okke Batelaan wrote:
>Hi Simon,
>v.what would be really handy. Is your s.what somewhere available?

Here is s.what - snip at the line and put it in your grass/scripts directory.

Simon Cox

> _________________________________________________________
> Dr Simon Cox                        __  \
> CSIRO Exploration & Mining       ,~'  L_|\    Australian
> 39 Fairway, PO Box 437,       ;-'         \   Geodynamics
> Nedlands, WA  6009  Australia (            \  Cooperative
>       Phone +61 9 284 8443    +    ___     /  Research
>       Fax   +61 9 389 1906     L~~'   "\__/   Centre
> simon at ned.dem.csiro.au                   W
> AGCRC info>>   http://www.ned.dem.csiro.au/AGCRC/
> _________________________________________________________

------8<-----------------------------8<------------
#! /bin/sh
# button instructions and error messages go to stderr
# coordinates and site information go to stdout

# s.what
#
# is a quick hack to get a program with similar functionality
# to r.what for non-interactive query of a site-list.
#
# 1/96  Simon Cox , AGCRC, CSIRO Exploration & Mining
#       simon at ned.dem.csiro.au
#
# - based on code fragments supplied by Sue Huse, REGIS, Berkeley.
#
# Performance not guaranteed.
#

if [ $# -lt 1 ]
then
        echo "usage:  s.what in=site_list < coord_list"
        exit
fi

sitename=`echo $1 | sed 's/in=//'`

#
# find the sites file or give error if not available
#
eval `g.findfile element=site_lists file=$sitename`
        if [ ! "$file" ]
        then
                echo "Site file $sitename unavailable" | cat 1>&2
                exit 1
        else
                sitefile=$file
        fi

#
#  loop through input lines
#

while read easting northing
do

if [ "X$easting" = "X" ]
then
        exit
fi
if [ "X$northing" = "X" ]
then
        exit
fi

#
# calculate the distance from point to each site in file and
# choose the closest
# uses (x2 + y2) rather than sqrt(x2 + y2) to minimize computation.
#

eval ` echo "nawk -F\"|\" '
        BEGIN { min_distance = 0;
                east = $easting;
                north = $northing
                 } \
        {

        distance = (\\\$1-east)^2 + (\\\$2-north)^2;
        if (min_distance == 0) {
                min_distance = distance;
                site_east = \\\$1;
                site_north = \\\$2;
                site_label = \\\$3;
                line_no = NR;
                };
        if (distance < min_distance) {
                min_distance = distance;
                site_east = \\\$1;
                site_north = \\\$2;
                site_label = \\\$3;
                line_no = NR;
                }
        }
        END { print site_east\"|\"site_north\"|\"site_label ;
                exit line_no
                } ' $sitefile" `


done