Version runs correctly, though the CDEM edge input image might not be the latest and best. Recheck inputs
ReadMe file describes how to use shell scripts (also checked in) to create example Srtm/Aster DEM image mosaic of Western Canada region spanning 60 deg N Latitude boundary
Sample output file from R script makeMarkTable.r - sample of 4000 random columns, row 5 through row 8 straddling 60 degree boundary.
Producing valid table, but from column samples taken entirely from mosaic. Next step: take them from Aster and Cgiar images.
First version, has issues with column indexing, I am fixing tonight.
Added collection of Linux shell scripts and R scripts that I used in my initial analysis of SRTM/CGIAR, CDEM, and ASTER GDEM digital terrain data sets.