defaultm (Mapping Toolbox)

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

`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