MAP_CONTINENTS

The MAP_CONTINENTS procedure draws continental boundaries, filled continents, political boundaries, coastlines, and/or rivers, over an existing map projection established by MAP_SET. 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.

MAP_SET must be called before MAP_CONTINENTS to establish the projection type, the center of the projection, polar rotation and geographic limits.

Keywords

COASTS

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.

COLOR

The color index of the lines being drawn.

COUNTRIES

Set this keyword to draw political boundaries as of 1993.

FILL_CONTINENTS

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.

HIRES

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.

MLINESTYLE

The line style of the boundaries being drawn. The default is solid lines. Valid linestyles are shown in the table below:

IDL Linestyles
Index	Linestyle
0	Solid
1	Dotted
2	Dashed
3	Dash Dot
4	Dash Dot Dot Dot
5	Long Dashes

MLINETHICK

The thickness of the boundary or fill lines. The default thickness is 1.

ORIENTATION

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.

RIVERS

Set this keyword to draw rivers.

SPACING

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.

USA

Set this keyword to draw borders for each state in the United States in addition to continental boundaries.

Example

The following example demonstrates the use of the map outlines to embellish a map projection:

tek_color ; Load discrete color table.

black=0 & white=1 & red=2

green=3 & dk_blue=4 & lt_blue=5 ; Match color indices to colors we want to use.

MAP_SET, /ORTHO, 40, -30, 23, /ISOTROPIC, $
; Set up an orthographic projection centered over the north Atlantic.

/HORIZON, E_HORIZON={FILL:1, COLOR:dk_blue}, $
; Fill the hemisphere with dark blue.

/GRID, COLOR=black; Specify black gridlines

MAP_CONTINENTS, /FILL_CONTINENTS, COLOR=white
; Fill the continent boundaries with solid white.

MAP_CONTINENTS, /COASTS, COLOR=black ; Overplot coastline data.

MAP_CONTINENTS, /RIVERS, COLOR=lt_blue ; Add rivers, in light blue.

MAP_CONTINENTS, /COUNTRIES, COLOR=red, MLINETHICK=2
; Show national borders.