Module talk:Canada NTS

maps of water

why? series 121, 341, 561, 780, 781, 910, may exist at https://maps.canada.ca/czs/index-en.html when the National Tiling System grid coverage is turned on (911 doesn't appear to exist there) but all that is within those grids is a lot of cold cold water. Why bother with that in this module? Does the mapping shift to nautical charts for those regions? And what about the other series omitted from File:NTS Zones and Map Series Numbers.png (0, 4–9, 17–19, 28, 50, 51, 60, 61, 70, 71, 80, 81, 90, 91, 100, 101, 108, 109, 118, 119)? Presumably there are no maps for those series; if there were, wouldn't series 0, 4–9, 17–19 etc NTS map sheet names be in Module:Canada NTS/data?

I've written a more strict lat/lon validator that returns false when lat/lon are outside the bounds of the grid overlay in File:NTS Zones and Map Series Numbers.png. The validator prevents grid() from calculating NTS IDs for points outside of the overlay by returning early with an error message. Using that validator means that for points in series 121, 341, 561, 780, 781, 910 (and 911 if it exists), grid() will return an error message so there is no need to accommodate those series within grid().

—Trappist the monk (talk) 20:00, 29 March 2022 (UTC)[reply]

That is the furthest extent of the National Tiling System. This is usable as a coarse method of geocoding, but the fact that the "name" function does not return any names for those areas is the sole indication that the National Topographic System has no map data there. Remember that the National Topographic System is the actual map catalogue, and the National Tiling System is the indexing system that the National Topographic System uses, and the National Tiling System covers a greater area than what the National Topographic System covers. If you wish to restrict the output of the grid function to the area covered by File:NTS Zones and Map Series Numbers.png, I will certainly let it stand. -- Denelson 83 23:18, 29 March 2022 (UTC)[reply]