/*  demhist1.aml
/*  aml to make a histogram of a DEM
/*  to be run from GRID
/*     Ralph Haugerud, USGS Seattle
/*     April 1998
/*       rhaugerud@usgs.gov

&arg ingrid

&describe %ingrid%
&set min = [calc %GRD$MEAN% - 100]
&set max = [calc %GRD$MEAN% + 100]
/* offset value may need to be changed for grids derived from maps with
/* contour intervals close to, or larger than, 100 units

%ingrid%h1 = con(%ingrid% > %min% AND %ingrid% < %max%, %ingrid%)
/* TRANSLATION: if ingrid > min and < Max, newgrid = ingrid, else newgrid = nodata

histogram %ingrid%h1

&return