MAPOPT structure

The MAPOPT structure is subdivided into several topical groups of properties:

Map Projection Stuff
Field Type Units Description
.proj_type string predefined values Name of the map projection
.proj_scale number - projection scale to be used (currently not evaluated, map scale is always 1:1 in MatLab and the depends on window or paper size)
.proj_range numeric array degree 4 element vector [minlon maxlon minlat maxlat] that defines the area shown in the map. minlon might be negative, but abs(maxlon-minlon) must be <360deg.
.proj_specops undefined undefined special options needed by the projection The content of this is not defined here. Some projections need additional parameters like tangent-parallels and the like. Such data is stored here. See the projection routines to find details.
.proj_pole numeric array degree This is a two element vector [lon lat] which defines a rotation of the coordinate frame. Data will be rotated by lon degrees eastward and then by 90-lat degrees northward. DEFAULT: empty
longitude has to be counted eastward from 0 to 360
latitude has to be counted northward from -90 to 90

If this is empty, no rotation will be applied. Plotting the map is much faster then, because delaunay triangulation has to be applied to rotated topo data. Depending on the projection, the behaviour of rotation may be unexpected. Try plotting maps with [0,0], [0,90], [90,0] to get an idea of what you have to choose. When using rotation, it is recommended to plot grid lines with a high number of points per line and in '.' style.
Planet Size Stuff
Field Type Units Description
.planet_type string predefined values Ellipsoid type Planets may be uniaxial, biaxial or triaxial ellipsoids possible values are:
'uni', 'sphere': Uniaxial is a sphere, of course.
'bi': Biaxial is a rotational ellipsoid.
'tri': Triaxial is a triaxial ellipsoid.
Axes of biaxial and triaxial planets are expected to be polar and in equatorial plane.
.planet_radius numeric array km 1, 2, or 3 element vector of radius values, in km For uniaxial (spherical) planets, only the first element is used. For biaxial planets, elements 1 and 2 are used. For triaxial planets, all three elements are used. Axis orientation is defined by .PLANET_ORIENT substructure. The mapping module currently supports only spherical planets.
.planet_orient numeric array degree Ellipsoid axis orientation for triaxial planets This substructure defines the points at the surface to which the three axes of the ellipsoid point. Not that axes are not necessarily polar/equatorial!
planet_orient(1,1): longitude of planet_radius(1) [deg]
planet_orient(1,2): latitude of planet_radius(1) [deg]
planet_orient(2,1): longitude of planet_radius(2) [deg]
planet_orient(2,2): latitude of planet_radius(2) [deg]
planet_orient(3,1): longitude of planet_radius(3) [deg]
planet_orient(3,2): latitude of planet_radius(3) [deg]
The mapping module currently supports only spherical planets.
Topography Data Stuff
Field Type Units Description
.topo_mode string predefined values switch to enable or disable topography plotting
'on': the topography will be plotted
'off': the topography will not be plotted.
DEFAULT: 'on'
.topo_path string - path to .mat file containing topography data The topography file is expected to contain the following matrix:
topo: matrix of elevation values, with topo(1,1) being the elevation at 0degE, 90degS and topo(end,end) being the elevation at 360degE, 90degN
OPTIONAL:
a matrix LON with longitude values and a matrix LAT with latitude values for each element of TOPO.
.topo_range numeric array degree 4 element matrix defining coordinate range of topo data [minlon maxlon minlat maxlat], all given in degrees, longitude positive to east, latitude positive to north if the data givn here is not compatible to LON and LAT data given in the topo file, these are overridden! To avoid this, set .TOPO_RANGE to empty!
NOTE: this property defines the size of the topo data set, not the area shown in the map! (that's .proj_range)
.topo_exag numeric - topography exaggeration factor topography will be multiplied by map scale and then by this factor This results in a vertical exaggeration of topography withn respect to horizontal extent by factor .TOPO_EXAGG. This affects the shading.
Grid Stuff
Field Type Units Description
.grid_mode string predefined values grid plot mode
'on': a grid will be drawn according to the grid parameters
'off': no gridd will be drawn, parameters are irrelevant.
.grid_range numeric array degree Area of the map to be covered with lon/lat grid 4 element vector [minlon maxlon minlat maxlat] If not specified explicitly, this will be equal to [0 360 -90 90]
.grid_lonmesh numeric degree grid mesh width in longitude direction
.grid_latmesh numeric degree grid mesh width in latitude direction
.grid_points numeric - number of points per grid line
.grid_color numeric or string ColorSpec grid line color, specified as MatLab ColorSpec (name string or RGB triple)
.grid_style string LineSpec grid line style, specified as MatLab LineSpec string (e.g. 'b.-')
Frame Stuff
Field Type Units Description
.frame_mode string predefined values frame plot mode
'on': a frame will be drawn around the map
'off': no frame will be drawn
.frame_color numeric or string ColorSpec Frame line color, specified as MatLab ColorSpec (name string or RGB triple)
.frame_style string LineSpec Frame line style, specified as MatLab LineSpec (e.g. 'b.-')
Colorbar Stuff
Field Type Units Description
.colorbar_mode string predefined values colorbar plot mode
'on' plots a colorbar under or beside map
'off' does not plot a colorbar
.colorbar_dir string predefined values colorbar orientation
'hor': horizontal colorbar under map
'vert': vertical colorbar beside map

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