The MAP_CONTINENTS procedure draws continental boundaries, filled continents, political boundaries, coastlines, and/or rivers, over a map projection. Outlines can be drawn in low or high-resolution (if the optional high-resolution CIA World Map database is installed). If MAP_CONTINENTS is called without any keywords, it draws low-resolution, unfilled continent outlines.
The MAP_STRUCTURE keyword can be used to draw directly to UV (Cartesian) coordinates. Otherwise, MAP_SET must be called before MAP_CONTINENTS to establish the projection type, the center of the projection, polar rotation and geographic limits.
MAP_CONTINENTS [, /COASTS] [, COLOR=index] [, /CONTINENTS] [, /COUNTRIES] [ ,FILL_CONTINENTS={1 | 2}[, ORIENTATION=value]] [, /HIRES] [, LIMIT=vector] [, MAP_STRUCTURE=structure] [, MLINESTYLE={0 | 1 | 2 | 3 | 4 | 5}] [, MLINETHICK=value] [, /RIVERS] [, SPACING=centimeters] [, /USA]
Graphics Keywords: [, /T3D] [, ZVALUE=value{0 to 1}]
Set this keyword to draw coastlines, islands, and lakes instead of the default continent outlines. Note that if you are using the low-resolution map database (if the HIRES keyword is not set), many islands are drawn even when COASTS is not set. If you are using the high-resolution map database (if the HIRES keyword is set), no islands are drawn unless COASTS is set.
Set this keyword to the color index of the lines being drawn.
Set this keyword to plot the continental boundaries. This is the default, unless COASTS, COUNTRIES, RIVERS and/or USA is set.
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Set this keyword to draw political boundaries as of 1993.
Set this keyword to 1 to fill continent boundaries with a solid color. The color is set by the COLOR keyword. Set this keyword to 2 to fill continent boundaries with a line fill. For line filling, the COLOR, MLINESTYLE, MLINETHICK, ORIENTATION, and SPACING keywords can be used to control the type of line fill.
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Set this keyword to use high-resolution map data instead of the default low-resolution data. This option is only available if you have installed the optional high-resolution map datasets. If the high-resolution data is not available, a warning is printed and the low-resolution data is used instead.
This keyword can be used in conjunction with the COASTS, COUNTRIES, FILL_CONTINENTS, and RIVERS keywords.
Set this keyword to a four-element vector [Latmin, Lonmin, Latmax, Lonmax] to only plot continents that pass through the LIMIT rectangle. The points (Latmin, Lonmin) and (Latmax, Lonmax) are the latitudes and longitudes of two points diagonal from each other on the region's boundary. The default is to use the limits from the current map projection.
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Set this keyword to a
The line style of the boundaries being drawn. The default is solid lines. Valid linestyles are shown in the table below:
The thickness of the boundary or fill lines. The default thickness is 1.
Set this keyword to the counterclockwise angle in degrees from horizontal that the line fill should be drawn. The default is 0. This keyword only has effect if the FILL_CONTINENTS keyword is set to 2.
Set this keyword to draw rivers.
Set this keyword to the spacing, in centimeters, for a line fill. This keyword only has effect if the FILL_CONTINENTS keyword is set to 2. The default is 0.5 centimeters.
Set this keyword to draw borders for each state in the United States in addition to continental boundaries.
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See Graphics Keywords, for descriptions of graphics and plotting keywords not listed above. T3D, ZVALUE.
The following example demonstrates the use of map outlines to embellish a map projection:
; Handle TrueColor displays: DEVICE, DECOMPOSED=0 ; Load discrete color table: tek_color ; Match color indices to colors we want to use: black=0 & white=1 & red=2 green=3 & dk_blue=4 & lt_blue=5 ; Set up an orthographic projection centered over the north ; Atlantic.Fill the hemisphere with dark blue. Specify black ; gridlines: MAP_SET, /ORTHO, 40, -30, 23, /ISOTROPIC, $ /HORIZON, E_HORIZON={FILL:1, COLOR:dk_blue}, $ /GRID, COLOR=black ; Fill the continent boundaries with solid white: MAP_CONTINENTS, /FILL_CONTINENTS, COLOR=white ; Overplot coastline data: MAP_CONTINENTS, /COASTS, COLOR=black ; Add rivers, in light blue: MAP_CONTINENTS, /RIVERS, COLOR=lt_blue ; Show national borders: MAP_CONTINENTS, /COUNTRIES, COLOR=red, MLINETHICK=2
The following example uses the MAP_STRUCTURE keyword to map the continents in UV (Cartesian) coordinates, without having to set up a
; GCTP Polar stereographic projection mapStruct = MAP_PROJ_INIT(106, LIMIT=[0,-180,90,180], $ CENTER_LATITUDE=90) ; Create a plot window using the UV Cartesian range. PLOT, mapStruct.uv_box[[0,2]],mapStruct.uv_box[[1,3]], $ /NODATA, /ISOTROPIC, XSTYLE=1, YSTYLE=1 MAP_CONTINENTS, MAP_STRUCTURE=mapStruct MAP_GRID, MAP_STRUCTURE=mapStruct
Introduced: Pre 4.0
MAP_STRUCTURE keyword added: 6.1
MAP_GRID, MAP_IMAGE, MAP_PATCH, MAP_PROJ_INIT, MAP_SET