Module:Location map/data/Tuvalu/doc

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This is the documentation page for Module:Location map/data/Tuvalu

Template:Location map Tuvalu is a location map definition used to overlay markers and labels on an equirectangular projection map of Tuvalu. It is used by "Template:Location map" when invoked with parameter "Tuvalu": {{Location map | Tuvalu | ...}}. The markers are placed by latitude and longitude coordinates on the default map or a similar map image.

[[Image:Template:Location map/data/Tuvalu|left|thumb|200px|Location map for Template:Location map/data/Tuvalu]]

Map parameters
name Template:Location map/data/Tuvalu name used in default map caption
image Template:Location map/data/Tuvalu file name of map image, without "Image:" or "File:"
x Template:Location map/data/Tuvalu an expression which evaluates as 0 along the left edge of the map, and 100 along the right edge of the map, where {{{2}}} and {{{3}}} are the degrees latitude and longitude respectively.
y Template:Location map/data/Tuvalu an expression which evaluates as 0 along the top edge of the map, and 100 along the bottom edge of the map, where {{{2}}} and {{{3}}} are the degrees latitude and longitude respectively.

Usage

For a description of the parameters, see {{Location map}} and {{Location map many}}.

Location map: Eastern hemisphere, Deg/Min/Sec coordinates

Location of Nanumea in Tuvalu
{{Location map | Tuvalu
| width = 150 | float = right
| caption = Location of [[Nanumea]] in Tuvalu
| label = Nanumea
| background = lightblue
| position = right
| lat_deg= 05 | lat_min=41 | lat_sec= | lat_dir=S
| lon_deg=176 | lon_min=12 | lon_sec= | lon_dir=E
}}

Location map: Eastern hemisphere, Decimal coordinates

Lua error in Module:Location_map at line 501: Unable to find the specified location map definition: "Module:Location map/data/Tuvalu,uasimoa" does not exist.

{{Location map | Tuvalu
| width = 150 | float = right
| caption = Location of [[Nanumea]] in Tuvalu
| label = Nanumea
| background = lightblue
| position = right
| lat = -5.683
| long = 176.2
}}

Location map: Western hemisphere, Deg/Min/Sec coordinates

Coordinates on Tuvalu map
{{Location map | Tuvalu
| width = 150 | float = right
| caption = Coordinates on Tuvalu map
| label = 10°15′S 179°59′W
| background = lightgreen
| position = left
| lat_deg= 10 | lat_min=15 | lat_sec= | lat_dir=S
| lon_deg=179 | lon_min=59 | lon_sec= | lon_dir=W
}}

Location map: Western hemisphere, Decimal coordinates

Coordinates on Tuvalu map
{{Location map | Tuvalu
| width = 150 | float = right
| caption = Coordinates on Tuvalu map
| label = -10.25, -179.983333
| background = lightgreen
| position = left
| lat = -10.25
| long = -179.983333
}}

Technical details

For a map using an equirectangular projection which does not cross +/-180 longitude, or +/-90 latitude, the following expressions can be used:

x = 100*(long - left)/(right - left)
y = 100*(lat - top)/(bottom - top)

where lat and long are the degrees latitude and longitude respectively. Here, top and bottom are the degrees latitude of the top and bottom edges of the map, left and right are the degrees latitude of the left and right edges of the map.

Things are a bit more complicated when the map crosses +/-180 longitude, and some sort of "modulo arithmetic" is required. Here, we add 360 if the longitude is less than 0, then use a mapping based on positive coordinates. The following table can be used to check if the expressions are working as desired:

location lat long (x,y) test (x,y) exact
top/left -5.3 175.7 (Expression error: Unrecognized punctuation character "[".,Expression error: Unrecognized punctuation character "[".) (0,0)
top/right -5.3 -179.8 (Expression error: Unrecognized punctuation character "[".,Expression error: Unrecognized punctuation character "[".) (100,0)
bottom/left -11.0 175.7 (Expression error: Unrecognized punctuation character "[".,Expression error: Unrecognized punctuation character "[".) (0,100)
bottom/right -11.0 -179.8 (Expression error: Unrecognized punctuation character "[".,Expression error: Unrecognized punctuation character "[".) (100,100)
center -8.15 177.95 (Expression error: Unrecognized punctuation character "[".,Expression error: Unrecognized punctuation character "[".) (50,50)