axesm
Create axesm-based map
Description
The axesm function creates an
axesm-based map (previously referred to as map axes) into which
both vector and raster geographic data can be projected using functions such as
plotm and geoshow. Properties specific to
axesm-based maps can be assigned upon creation with
axesm, and for an existing axesm-based map
they can be queried and changed using getm and
setm. Use the standard get and
set methods to query and control the standard MATLAB® axes properties of an axesm-based map.
An axesm-based map is a standard MATLAB axes with different default settings for some properties and a MATLAB structure for storing projection parameters and other data. The main
differences in default settings are:
Axes properties
XGrid,YGrid,XTick,YTickare set to'off'.The
holdmode is'on'.
The map projection structure stores the properties of the
axesm-based map, which, in addition to the special standard axes
settings, allow Mapping Toolbox™ functions to recognize an axes or an opened FIG-file as an
axesm-based map. See axesm-Based Map Properties
for descriptions of the axesm-based map properties.
axesm with no input arguments, initiates the
axesmui graphical user interface, which can be used to set
the properties of the axesm-based map. This is detailed on the
axesmui reference page.
axesm( creates an
Name,Value)axesm-based map and modifies the appearance using
name-value pairs to set properties. You can specify multiple name-value pairs.
Enclose each property name in quotes. For example, 'FontSize',14
sets the font size for the map text. Properties may be specified in any order, but
the MapProjection property must be included. For a full list of
properties, see axesm-Based Map Properties.
axesm(
specifies which map projection to use. projid,Name,Value)projid should match one of
the entries in the last column displayed by the maps function. You can also find these listed in Summary and Guide to Projections.
Examples
Create an axesm-based map for a Mercator projection,
with selected latitude limits:
axesm('MapProjection','mercator','MapLatLimit',[-70 80])
All properties not explicitly addressed in the call are set to either
fixed or calculated defaults. The file mercator.m defines
a projection function, so the same result could have been achieved with the
function.
axesm('mercator','MapLatLimit',[-70 80])
Each projection function includes default values for all properties. Any following property name/property value pairs are treated as overrides.
In either of the above examples, data displayed in the given map is in a Mercator projection. Any data falling outside the prescribed limits is not displayed.
Similar to accessing and manipulating standard axes properties by using the get and set functions, you can access and manipulate the properties of axesm-based maps by using the getm and setm functions.
Use the axesm function only to create an axesm-based map. Use the setm function to modify an existing axesm-based map.
Create an axesm-based map that contains no map data. Note that you specify MapProjection ID values in lowercase.
axesm('MapProjection','miller','Frame','on')
At this point you can begin to customize the map. For example, you might decide to make the frame lines bordering the map thicker. First, you need to identify the current line width of the frame, which you do by querying the current axes, identified as gca.
getm(gca,'FLineWidth')ans = 2
Now reset the line width to four points. The default fontunits value for axes is points. You can set fontunits to be points, normalized, inches, centimeters, or pixels.
setm(gca,'FLineWidth',4)
You can set any number of properties simultaneously with setm. Continue by reducing the line width, changing the projection to equidistant cylindrical, and verify the changes.
setm(gca,'FLineWidth',3,'Grid','on','MapProjection','robinson')
getm(gca,'FLineWidth')ans = 3
getm(gca,'MapProjection')ans = 'robinson'
Inspect the entire set of map properties at their current settings. Note that the list of properties includes both those particular to axesm-based maps and general ones that apply to all MATLAB® axes.
getm(gca)
ans = struct with fields:
mapprojection: 'robinson'
zone: []
angleunits: 'degrees'
aspect: 'normal'
falsenorthing: 0
falseeasting: 0
fixedorient: []
geoid: [1 0]
maplatlimit: [-90 90]
maplonlimit: [-180 180]
mapparallels: 38
nparallels: 0
origin: [0 0 0]
scalefactor: 1
trimlat: [-90 90]
trimlon: [-180 180]
frame: 'on'
ffill: 100
fedgecolor: 'default'
ffacecolor: 'none'
flatlimit: [-90 90]
flinewidth: 3
flonlimit: [-180 180]
grid: 'on'
galtitude: Inf
gcolor: 'default'
glinestyle: ':'
glinewidth: 0.5000
mlineexception: []
mlinefill: 100
mlinelimit: []
mlinelocation: 30
mlinevisible: 'on'
plineexception: []
plinefill: 100
plinelimit: []
plinelocation: 15
plinevisible: 'on'
fontangle: 'normal'
fontcolor: 'default'
fontname: 'Helvetica'
fontsize: 10
fontunits: 'points'
fontweight: 'normal'
labelformat: 'compass'
labelrotation: 'off'
labelunits: 'degrees'
meridianlabel: 'off'
mlabellocation: 30
mlabelparallel: 90
mlabelround: 0
parallellabel: 'off'
plabellocation: 15
plabelmeridian: -180
plabelround: 0
Similarly, use the setm function alone to display the set of properties, their enumerated values, and defaults.
setm(gca)
AngleUnits [ {degrees} | radians ]
Aspect [ {normal} | transverse ]
FalseEasting
FalseNorthing
FixedOrient FixedOrient is a read-only property
Geoid
MapLatLimit
MapLonLimit
MapParallels
MapProjection
NParallels NParallels is a read-only property
Origin
ScaleFactor
TrimLat TrimLat is a read-only property
TrimLon TrimLon is a read-only property
Zone
Frame [ on | {off} ]
FEdgeColor
FFaceColor
FFill
FLatLimit
FLineWidth
FLonLimit
Grid [ on | {off} ]
GAltitude
GColor
GLineStyle [ - | -- | -. | {:} ]
GLineWidth
MLineException
MLineFill
MLineLimit
MLineLocation
MLineVisible [ {on} | off ]
PLineException
PLineFill
PLineLimit
PLineLocation
PLineVisible [ {on} | off ]
FontAngle [ {normal} | italic | oblique ]
FontColor
FontName
FontSize
FontUnits [ inches | centimeters | normalized | {points} | pixels ]
FontWeight [ {normal} | bold ]
LabelFormat [ {compass} | signed | none ]
LabelRotation [ on | {off} ]
LabelUnits [ {degrees} | radians ]
MeridianLabel [ on | {off} ]
MLabelLocation
MLabelParallel
MLabelRound
ParallelLabel [ on | {off} ]
PLabelLocation
PLabelMeridian
PLabelRound
Many, but not all, property choices and defaults can also be displayed individually.
setm(gca,'FontUnits')FontUnits [ inches | centimeters | normalized | {points} | pixels ]
setm(gca,'MapProjection')An axes's "MapProjection" property does not have a fixed set of property values.
setm(gca,'Frame')Frame [ on | {off} ]
setm(gca,'FixedOrient')FixedOrient FixedOrient is a read-only property
In the same way, getm displays the current value of any axes property.
getm(gca,'FontUnits')ans = 'points'
getm(gca,'MapProjection')ans = 'robinson'
getm(gca,'Frame')ans = 'on'
getm(gca,'FixedOrient')ans =
[]
To identify which properties apply to a given map projection, see the reference page for that projection.
Input Arguments
Name-Value Arguments
Tips
In general, after re-opening a saved figure that contains an
axesm-based map, you should not attempt to modify the projection properties of that map.When you create an
axesm-based map withaxesmand right click in the axes, a context menu appears. If you do not need the menu or it interferes with your application, you can disable it by resetting the'ButtonDownFcn'property of the axes:ax = axesm('mercator'); % Right-clicking brings up context menu. set(ax,'ButtonDownFcn',[]) % Context menu has been disabled.
By default,
axesmdoes not clip graticules or labels that occur outside the boundaries of the axes. Enable clipping by setting the'Clipping'property of these objects.objects = [handlem('grid'); handlem('mlabel'); handlem('plabel')]; set(objects,'Clipping','on');
Version History
Introduced before R2006a
