Mapping Toolbox

defaultm

Initialize a default map projection structure

Syntax

• mstruct = defaultm
  mstruct = defaultm(projection)
  mstruct = defaultm(mstruct)
  [mstruct,msg] = defaultm(...)
  

Description

The map projection structure contains all the information needed to project and display geographic data. It normally resides in the UserData property of a map axes, but it can also be used directly to project data without display.

mstruct = defaultm creates an empty map projection structure.

mstruct = defaultm(projection) initializes the map structure for the specified map projection. projection is any valid projection string, such as 'sinusoid'.

mstruct = defaultm(mstruct) sets appropriate defaults based on existing parameter values in the map structure mstruct.

[mstruct,msg] = defaultm(...) returns the string msg, indicating any error encountered.

Examples

Create an empty map projection structure for a Mercator projection:

• mstruct = defaultm('mercator')
  mstruct = 
       mapprojection: 'mercator'
                zone: []
          angleunits: 'degrees'
              aspect: 'normal'
        falseeasting: []
       falsenorthing: []
         fixedorient: []
               geoid: [1 0]
         maplatlimit: []
         maplonlimit: []
        mapparallels: 0
          nparallels: 1
              origin: []
         scalefactor: []
             trimlat: [-86 86]
             trimlon: [-180 180]
               frame: []
               ffill: 100
          fedgecolor: [0 0 0]
          ffacecolor: 'none'
           flatlimit: []
          flinewidth: 2
           flonlimit: []
                grid: []
           galtitude: Inf
              gcolor: [0 0 0]
          glinestyle: ':'
          glinewidth: 0.5000
      mlineexception: []
           mlinefill: 100
          mlinelimit: []
       mlinelocation: []
        mlinevisible: 'on'
      plineexception: []
           plinefill: 100
          plinelimit: []
       plinelocation: []
        plinevisible: 'on'
           fontangle: 'normal'
           fontcolor: [0 0 0]
            fontname: 'helvetica'
            fontsize: 9
           fontunits: 'points'
          fontweight: 'normal'
         labelformat: 'compass'
       labelrotation: 'off'
          labelunits: []
       meridianlabel: []
      mlabellocation: []
      mlabelparallel: []
         mlabelround: 0
       parallellabel: []
      plabellocation: []
      plabelmeridian: []
         plabelround: 0
  

Now change the map origin to [0 90 0], and fill in default projection parameters accordingly:

• mstruct.origin = [0 90 0];
  mstruct = defaultm(mstruct)
  mstruct = 
       mapprojection: 'mercator'
                zone: []
          angleunits: 'degrees'
              aspect: 'normal'
        falseeasting: 0
       falsenorthing: 0
         fixedorient: []
               geoid: [1 0]
         maplatlimit: [-86 86]
         maplonlimit: [-180 180]
        mapparallels: 0
          nparallels: 1
              origin: [0 0 0]
         scalefactor: 1
             trimlat: [-86 86]
             trimlon: [-180 180]
               frame: 'off'
               ffill: 100
          fedgecolor: [0 0 0]
          ffacecolor: 'none'
           flatlimit: [-86 86]
          flinewidth: 2
           flonlimit: [-180 180]
                grid: 'off'
           galtitude: Inf
              gcolor: [0 0 0]
          glinestyle: ':'
          glinewidth: 0.50000000000000
      mlineexception: []
           mlinefill: 100
          mlinelimit: []
       mlinelocation: 30
        mlinevisible: 'on'
      plineexception: []
           plinefill: 100
          plinelimit: []
       plinelocation: 15
        plinevisible: 'on'
           fontangle: 'normal'
           fontcolor: [0 0 0]
            fontname: 'helvetica'
            fontsize: 9
           fontunits: 'points'
          fontweight: 'normal'
         labelformat: 'compass'
       labelrotation: 'off'
          labelunits: 'degrees'
       meridianlabel: 'off'
      mlabellocation: 30
      mlabelparallel: 86
         mlabelround: 0
       parallellabel: 'off'
      plabellocation: 15
      plabelmeridian: -180
         plabelround: 0
  

See Also

axesm	Define map axes and set map properties
gcm	Get current map data structure
mfwdtran	Map forward transformation
minvtran	Map inverse transformation
setm	Set and modify map properties

daspectm

deg2dms, deg2dm