Module:Canada NTS explained

require('strict'); -- alarm when global variables etc are used

local get_args = require ('Module:Arguments').getArgs; -- simplfy frame and parent frame argument fetching

--

local function wikidata_lat_lon_get local qid = mw.wikibase.getEntityIdForCurrentPage; -- get the qid for the current page if qid then local value_t = mw.wikibase.getBestStatements (qid, 'P625')[1]; -- attempt to get P625; nil when article does not have P625 if value_t then value_t = value_t.mainsnak.datavalue.value; --point to the value table return value_t.latitude, value_t.longitude; -- return coordinates from value_t end endend

--

local function article_name_from_qid_get (qid) local this_wiki_code = mw.language.getContentLanguage:getCode; -- get this wiki's language code if 'wikidata'

mw.site.server then this_wiki_code = mw.getCurrentFrame:callParserFunction('int',); -- on Wikidata so use interface language setting instead end

local wd_article = mw.wikibase.getSitelink (qid, this_wiki_code .. 'wiki'); -- fetch article title from WD; nil when no title available at this wiki

if wd_article then wd_article = table.concat ; -- interwiki-style link without brackets if taken from WD; leading colon required end

return wd_article; -- article title from WD; nil elseend

----------------------------< _ N A M E >--------------------------------------------------------------------

This function takes in a National Tiling System ID and outputs the name of the National Topographic System mapsheet with that ID. If no map sheet has been published under that ID, the output will be blank.

local function _name (args_t) local data_t = mw.loadData ('Module:Canada NTS/data'); -- load the ~/data module if not data_t[args_t[1]] then -- nil when NTS ID not listed in ~/data return ""; elseif

data_t[args_t[1]] then -- when sheet has no title return '(untitled)'; -- return a place-holder; lowercase here because capitalized implies that 'Untitled' is the 'title' end

local title_parts_t = mw.text.split (data_t[args_t[1]], '|'); -- title_parts[1] is link part of a wikilink; title_parts[2] is wikilink label (map name) or nil if mw.title.getCurrentTitle.text

title_parts_t[1] then -- don't create wikilink to the current article return title_parts_t[2] or title_parts_t[1]; -- return plaintext wikilink label or plain text article title (wikilink) end

return string.format ('%s', data_t[args_t[1]]); -- return wikilinked map titleend

--name|}}

local function name (frame) local args_t = get_args (frame); if not args_t[1] then return '

National Tiling System ID required'; -- TODO: better, more informative error handling end return _name (args_t);end

----------------------------< C O O R D _ L I M I T S _ T >--------------------------------------------------

a sequence of sequences. Each sequence in has two coordinate sequences that defines a rectangleidentified by the northwest and southeast corners of a subsection in the NTS series map. The first coordinate sequence identifies the northwestcorner of the subsection; the second sequence identifies the southwest corner of the subsection.

local coord_limits_t =

----------------------------< L A T _ L O N _ V A L I D A T E >----------------------------------------------

validates and to be inside one of the rectangles defined in

returns true when in bounds; false else

local function lat_lon_validate (lat, lon) for _, coord_limit_t in ipairs (coord_limits_t) do -- loop through the rectangle sequences in local lat_N = coord_limit_t[1][1]; -- for readability ... local lat_S = coord_limit_t[2][1]; local lon_W = coord_limit_t[1][2]; local lon_E = coord_limit_t[2][2];

if (lat >= lat_S) and (lat < lat_N) and (lon >= lon_E) and (lon < lon_W) then return true; -- and locate a point within bounds so done end end return false; -- and locate a point out of bounds so doneend

--

local function extents (lat, lon) local belt = math.floor((lat - 40) * 4); local strip = math.floor((lon - 48) * 2);

local s, n, e, w -- 1:50,000 scale bounding box local a_s, a_n, a_e, a_w -- 1:250,000 scale bounding box

local lat_limits = -- Latitude limits of bounding box

local lon_limits = -- Calculation of longitude limits is different depending on zone if lat >= 40 and lat < 68 then -- Southern zone lon_limits["e"] = strip / 2 + 48; lon_limits["w"] = strip / 2 + 48.5; lon_limits["a_e"] = math.floor(strip / 4) * 2 + 48; lon_limits["a_w"] = math.floor(strip / 4) * 2 + 50;

elseif lat >= 68 and lat < 80 then -- Arctic zone lon_limits["e"] = math.floor(strip / 2) + 48; lon_limits["w"] = math.floor(strip / 2) + 49; lon_limits["a_e"] = math.floor(strip / 8) * 4 + 48; lon_limits["a_w"] = math.floor(strip / 8) * 4 + 52;

elseif lat >= 80 and lat < 88 then -- High Arctic zone lon_limits["e"] = math.floor(strip / 2) + 48; lon_limits["w"] = math.floor(strip / 2) + 49; lon_limits["a_e"] = math.floor(strip / 8) * 4 + 48; lon_limits["a_w"] = math.floor(strip / 8) * 4 + 52; end return end

----------------------------< N T S _ I D _ F R O M _ L A T _ L O N _ G E T >--------------------------------

calculates NTS identifier from latitude and longitude. If and not supplied, attempts to fetchcoordinates from wikidata

when successful, returns NTS identifier; nil else

local function nts_id_from_lat_long_get (lat, lon) if not (lat and lon) then -- nil when missing, empty, or not a number lat, lon = wikidata_lat_lon_get; -- / template param(s) invalid or missing; attempt to get / from wikidata end -- wikidata uses negative numbers for west (and south) so must account for that if lat then -- normalize coords; assumes that given coords are intended to be on canada nts map if 0 > lat then lat = lat * -1.0; -- required because wikidata coords are signed end if 0 > lon then lon = lon * -1.0; -- required because wikidata coords are signed end else return nil; end if not lat_lon_validate (lat, lon) then return nil; -- / out of bounds; TODO: better error handling/messaging end

local series, numarea, area, sheet_inter, sheet if lat >= 40 and lat < 68 then -- Southern zone series = (math.floor((lon - 48) / 8) * 10) + math.floor((lat - 40) / 4) -- Calculate 1:1,000,000 map series ID numarea = tonumber(math.floor(((lat - 40) / 4) % 1 * 4) * 10 + math.floor(((lon - 48) / 8) % 1 * 4)) -- Calculate 1:250,000 map area ID local southern_zone_t = ; area = southern_zone_t[numarea]; -- translate sheet_inter = math.floor((lat % 1) * 4) * 10 + math.floor((((lon - 48) / 8) % 1 * 4) % 1 * 4) -- Calculate 1:50,000 map sheet ID

elseif lat >= 68 and lat < 80 then -- Arctic zone series = (math.floor((lon - 48) / 8) * 10) + math.floor((lat - 40) / 4) -- Calculate 1:1,000,000 map series ID numarea = (math.floor(lat % 4) * 10) + math.floor((lon / 4) % 2) -- Calculate 1:250,000 map area ID local arctic_zone_t = ; area = arctic_zone_t[numarea]; -- translate sheet_inter = math.floor((lat % 1) * 4) * 10 + math.floor(lon % 4) -- Calculate 1:50,000 map sheet ID

elseif lat >= 80 and lat < 88 then -- High Arctic zone if lon >= 56 and lon < 72 then -- Calculate 1:1,000,000 map series ID if lat >= 84 then series = 121 else series = 120 end -- These are correct - Go to , select "Overlay reference layers", then "National Tiling System grid coverage" elseif lon >= 72 and lon < 88 then -- there are no maps above 84°N so series 121, 341, and 561 do not exist in National Topographic System, but do exist in National Tiling System if lat >= 84 then series = 341 else series = 340 end elseif lon >= 88 and lon < 104 then if lat >= 84 then series = 561 else series = 560 end elseif lon >= 104 and lon < 120 then -- These are correct - Go to , select "Overlay reference layers", then "National Tiling System grid coverage" if lat >= 84 then series = 781 else series = 780 end -- 780, 781, 910, or 911 elseif lon >= 120 and lon < 136 then if lat >= 84 then series = 911 else series = 910 end end -- Remember the difference between the National Topographic System and the National Tiling System numarea = (math.floor(lat % 4) * 10) + (math.floor((lon / 8) + 1) % 2) -- Calculate 1:250,000 map area ID local high_arctic_zone_t = ; area = high_arctic_zone_t[numarea]; -- translate sheet_inter = math.floor((lat % 1) * 4) * 10 + math.floor((lon % 8) / 2) -- Calculate 1:50,000 map sheet ID end

local sheet_t = sheet = sheet_t[sheet_inter]

return series, area, sheetend

--

local function nts_series_validate (series) series = (series and tonumber (series)); -- convert series to a number if not series then return nil; -- something other than a number; declare failure and abandon end

local series_limits_t =

for _, limits_t in ipairs (series_limits_t) do -- loop through the series limits if (series >= limits_t[1]) and (series <= limits_t[2]) then -- is series within these limits? return series; -- yes, return series as a number end endend

--

local function nts_area_validate (series, area) local is_northern; -- a flag local northern_series_t = for _, limits_t in ipairs (northern_series_t) do if (series >= limits_t[1]) and (series <= limits_t[2]) then -- is series in arctic or high arctic? is_northern = true; -- yes, set the flag break; -- and go on to the next tests end end if is_northern then -- if arctic or high arctic series if not area:match ('^[A-H]$') then -- area must be a single uppercase letter in the range A-H return nil; -- out of bounds, declare failure and abandon end else -- here when southern series if not area:match ('^[A-P]$') then -- area must be a single uppercase letter in the range A-P return nil; -- out of bounds, declare failure and abandon end end

return area;end

--

local function nts_sheet_validate (sheet) sheet = (sheet and tonumber (sheet)) or nil; -- sheet as a number; or if not a number or not present, nil if not sheet then return nil; -- something other than a number; declare failure and abandon end

if (1 > sheet) or (16 < sheet) then -- must be a number in the range 1–16 return nil; -- out of bounds, declare failure and abandon end

return sheet; -- return sheet as a numberend

--

local function extents_from_grid (series, area, sheet) local belt -- 192 belts between 40°N and 88°N, each 0.25° of latitude in breadth local belt_area_south = local belt_area_north = local belt_sheet =

if series >= 120 then belt = 160 + series % 10 * 16 + (belt_area_north[area] or 0) + (belt_sheet[sheet] or 0) elseif series < 120 and series % 10 * 16 >= 112 then belt = series % 10 * 16 + (belt_area_north[area] or 0) + (belt_sheet[sheet] or 0) else belt = series % 10 * 16 + (belt_area_south[area] or 0) + (belt_sheet[sheet] or 0) end

local strip -- 192 strips between 48°W and 144°W, each 0.5° of longitude in breadth local strip_series_high_arctic = local strip_area_southern = local strip_area_arctic = local strip_area_high_arctic =

local strip_sheet_southern = local strip_sheet_arctic = local strip_sheet_high_arctic =

local east_limit, west_limit; -- For 1:50,000 scale map sheet local area_east_limit, area_west_limit; -- For 1:250,000 scale map area

if series >= 120 then -- High Arctic zone strip = strip_series_high_arctic[math.floor(series / 10)] + (strip_area_high_arctic[area] or 0) + (strip_sheet_high_arctic[sheet] or 0);

east_limit = strip * 0.5 + 48 west_limit = (strip + 4) * 0.5 + 48 area_east_limit = math.floor(strip / 16) * 8 + 48 area_west_limit = math.floor((strip + 16) / 16) * 8 + 48

elseif series < 120 and math.floor(series % 10) >= 7 then -- Arctic zone strip = math.floor(series / 10) * 16 + (strip_area_arctic[area] or 0) + (strip_sheet_arctic[sheet] or 0);

east_limit = strip * 0.5 + 48 west_limit = (strip + 2) * 0.5 + 48 area_east_limit = math.floor(strip / 8) * 4 + 48 area_west_limit = math.floor((strip + 8) / 8) * 4 + 48

else -- Southern zone strip = math.floor(series / 10) * 16 + (strip_area_southern[area] or 0) + (strip_sheet_southern[sheet] or 0);

east_limit = strip * 0.5 + 48 west_limit = (strip + 1) * 0.5 + 48 area_east_limit = math.floor(strip / 4) * 2 + 48 area_west_limit = math.floor((strip + 4) / 4) * 2 + 48

end local grid_limits = return grid_limitsend

--grid}} -- For 1:50,000 scale map sheet ID, using coordinates from current article's Wikidata entry -- For 1:50,000 scale map sheet ID, using NTS ID (see Template:Canada NTS Map Sheet) -- For 1:50,000 scale map sheet ID, using coordinates specified in argument

optional parameters: |area= to obtain a 1:250,000 scale map area ID instead |link= to create an appropriate link to the Canadian government's Geospatial Data Extraction tool |name= to append the map name (from Module:Canada_NTS/data) to the output

local function grid (frame) local args_t = get_args (frame); -- fetch frame and parent frame parameters into a single table local lat, lon = tonumber(args_t.lat), tonumber(args_t.lon); -- flags to control what the output looks like local print_area = 'yes'

args_t.area; -- when true, render only the 'area' portion '30M' instead of sheet '30M11' local print_link = 'yes'

args_t.link; -- when true, format the area or sheet output as an external link local print_name = 'yes'

args_t.name; -- when true, append map name from ~/data

local series, area, sheet; for k, v in ipairs (args_t) do if 1

k then -- args_t[1] to series; must be a one-to-three digit number series = nts_series_validate (args_t[1]); if not series then return '

invalid NTS series input'; end lat = nil; -- unset these if present because we won't be using them when we have nts id (which may or may not be good) lon = nil;

elseif 2

k then -- args_t[2] to area; must one uppercase letter A-P area = nts_area_validate (series, args_t[2]); if not area then return '

invalid NTS area input'; end

elseif 3

k then -- args_t[3] to sheet; must be a number 1-16 sheet = nts_sheet_validate (args_t[3]); if not sheet then return '

invalid NTS sheet input'; end end end

if series and not sheet then -- if we have nts id without sheet (an area-only) print_area = true; -- set this so that later we create the correct output end if not series or not area then series, area, sheet = nts_id_from_lat_long_get (lat, lon); if not series then return '

lat/long input fail'; -- TODO: better, more informative error handling end end

local output = print_area and (series .. area) or (series .. area .. sheet); print_name = print_name and (' ' .. _name) or ; -- reuse to hold name or empty string

local extents_t = ; -- to hold bounding box coordinates for url if print_link and lat then -- when we have lat/lon extents_t = extents (lat, lon); -- get a table of sheet and area extents from lat/lon elseif print_link then -- when we have nts id extents_t = extents_from_grid (series, area, sheet); -- get a table of sheet and area extents from nts id parts if extents_t

nil then return '

NTS identifier input fail'; -- TODO: better, more informative error handling end else print_link = nil; -- unset because we can't create a link end

if print_link then local ext_link_fmt_str = '%s'; output = print_area and string.format (ext_link_fmt_str, extents_t.area_west, extents_t.area_south, extents_t.area_east, extents_t.area_north, output, output) or string.format (ext_link_fmt_str, extents_t.west, extents_t.south, extents_t.east, extents_t.north, output, output); end

output = output .. print_name; -- append name or empty string return output; -- and doneend

----------------------------< D O C _ S U P P O R T >--------------------------------------------------------

local function doc_support (frame) local args_t = get_args (frame); -- fetch frame and parent frame parameters into a single table local data = mw.loadData ('Module:Canada NTS/data'); -- load the ~/data module local lang_obj = mw.language.getContentLanguage; -- get language object for number formatting local count = 0; -- a generic counter local area_count = 0; -- counter for area maps (1:250,000) local sheet_count = 0; -- counter for sheet maps (1:50,000) if 'count'

args_t[1] then -- count the number of entries in ~/data for k, _ in pairs (data) do -- don't care about key and value if k:match ('[A-P]$') then area_count = area_count + 1; -- bump the counter else sheet_count = sheet_count + 1; -- bump the counter end end return string.format ('%s (1:250,000: %s; 1:50,000: %s)', lang_obj:formatNum (sheet_count + area_count), lang_obj:formatNum (area_count), lang_obj:formatNum (sheet_count)); elseif 'untitled'

args_t[1] then -- count the number of entries in ~/data that do not have a NTS title for _, v in pairs (data) do -- don't care about key if

v then -- when value is empty string, no title so count = count + 1; -- bump the counter end end end

return lang_obj:formatNum(count); -- make all pretty-like and doneend

----------------------------< E X P O R T E D F U N C T I O N S >------------------------------------------

return