IONMapApplet

ION Java User's Guide: Using ION's Pre-Built Applets

IONMapApplet

The IONMapApplet is an applet that displays 2D data on a map projection. The data can be displayed as an image or a contour plot and can contain latitude/longitude grid lines, and landmass and political boundaries. The applet is capable of projecting multiple contour plots, one image, latitude/longitude grid lines, and boundaries onto the drawing area. In the case of multiple datasets, the drawing order is as follows:

Images are always drawn first

Any ordering of the following:

Grid Lines (drawn once)

Boundaries (continents, drawn once)

Contours (in numerical order)

The IONMapApplet is based on the ION[Gr]Map* and IONGrContour objects.

Note
You can also create plots using the IONGraphicApplet, specifying the map properties in IDL command strings. The IONMapApplet is merely a simplified way to display maps.

Parameters

In addition to the standard IONApplet parameters, the IONMapApplet accepts the following parameters:

IDL_COMMAND_n

A set of IDL commands starting with n=0 that are executed before the map commands

MAP_GRID

Display latitude/longitude lines on the map

MAP_CONT

Display continents on the map

MAP_[LAT,LON]

Center of the map

MAP_ROTATION

Rotation of the map

MAP_*

Keywords accepted by IONGrMap

MAP_GRID_*

Keywords accepted by IONGrMapGrids (valid if MAP_GRID is set)

MAP_CONT_*

Keywords accepted by IONGrContinents (valid if MAP_CONT is set)

MAP_IMAGE_DATA

An IDL statement that evaluates to a 2D dataset that is used as the image data

MAP_IMAGE_*

Keywords accepted by IONGrMapImage (valid if MAP_IMAGE_DATA is set)

MAP_CONTOURn_*

Keywords accepted by the IONContourApplet. n identifies the contour to which the keyword is applied. The applet starts processing at MAP_CONTOUR1 and continues sequentially until no more contours are encountered.

MAP_DISP_ORDER

Specifies the order that the data sets are displayed on the map. Valid orders are as follows (CTR = contour, CT = continents, GR = grid lines):

CTR_CT_GR, GTR_GR_CT

CT_CTR_GR, CT_GR_CTR

GR_CTR_CT, GR_CT_CTR

The following IDL MAP_SET properties are supported by IONMapApplet. Refer to the IDL documentation on keywords available for use with the MAP_SET procedure for an explanation of each property:

Projection Types: AITOFF, ALBERS, AZIMUTHAL, CONIC, CYLINDRICAL, GNOMIC, GOODESHOMOLOSINE, HAMMER, LAMBERT, MERCATOR, MILLER, MOLLEWIDE, ORTHOGRAPHIC, ROBINSON, SATELLITE, SINUSOIDAL, STEREOGRAPHIC, TRANSVERSE_MERCATOR

Map Characteristics: ADVANCE, CHARSIZE, CLIP, COLOR, CONTINENTS, CON_COLOR, HIRES, E_CONTINENTS, E_GRID, E_HORIZON, GLINESTYLE, GLINETHICK, GRID, HORIZON, LABEL, LATALIGN, LATDEL, LATLAB, LONDEL, LONLAB, MLINESTYLE, MLINETHICK, NOBORDER, NOERASE, TITLE, USA, XMARGIN, YMARGIN

Projection Parameters: CENTRAL_AZIMUTH, ELLIPSOID, ISOTROPIC, LIMIT, SAT_P, SCALE, STANDARD_PARALLELS

Graphics: POSITION, T3D, ZVALUE

IDL Online Help (March 06, 2007)