Defined in: iLand\map_doc.js:1
Module: iLand

The Map object encapsulates a "GIS" grid. Grids can be read from ESRI ASCII raster files, and are automatically mapped to a 10x10m grid (the resolution and extent of the height grid). Internally, a "spatial index" is created allowing for fast access to trees that lie on specific pixels. See also the wiki page landscape setup. The loaded map can be used, e.g., to specifically apply management on specific areas.

A newly created Map object (without a call to load()) points to the global stand grid defined in the project file.

Use load to read a raster file from disk.


function loadMap()
  var path = Globals.defaultDirectory("script"); // get project script folder; see also the "currentDir" property of "Globals". defaultDirectory() adds already a slash
  var stand_map = new Map();
  stand_map.load(path + "test.txt");
  // now load all trees on pixels with value '2020' in the "test.txt" grid
  management.loadFromMap(stand_map, 2020);
  // ... now do something ....

  var map = new Map();
  // select all trees on stand with id 127 of the 'system' stand grid
  management.loadFromMap(map, 127);



  • stand_id

Defined in iLand\map_doc.js:51

Retrieves the area of the polygon stand_id in square meters (m2). Returns -1, if the map is not valid, and 0 if no pixels with the stand stand_id are on the map.


  • stand_id Integer

    ID of the polygon for which to return the area.



The area (m2) of the polygon.



Defined in iLand\map_doc.js:68

Clears the map (set all values to 0)



Defined in iLand\map_doc.js:89

Clear only the project area (set all cell values to 0), but do not affect pixels that are "outside of project area" (i.e., have values of -1 and -2). (see Landscape setup)


  • stand_id
  • paint_function
  • wrap_around

Defined in iLand\map_doc.js:97

"Paint" a shape on the Map with an ID stand_id. The paint_function is a valid iLand Expression (with the paramters: xand y as metric coordinates). All pixels for which paint_function evaluates to true are set to stand_id, all other pixels are not modified.


  • stand_id Integer

    ID of the polygon to be created

  • paint_function String

    the function defining the shape

  • wrap_around Boolean

    if true, the shape is wrapped around the edges of the simulated area (torus)


var map = undefined;
                    // the function create 10 random circles
                    // with a radius between 10 and 60m on a random location on the landscape,
                    // and removes some of those trees
                    function random_circles()
                        if (map == undefined) {
                           map = new Map(); // create a new map
                        for (var i=1;i<10;++i) {
                            var x = Math.random() * 600;
                            var y = Math.random() * 400;
                            var r = 10 + Math.random() * 50;
                            // load all trees that are present on the stand
                            management.loadFromMap(map, i);
                            print(management.count + " trees in the area...");
                            // apply a special filter polygon
                            management.filter('polygon(dbh, 10,0, 30,1)');
                            print(management.count + " after filter: trees in the area...");
                            management.killAll(); // kill the trees


  • file_name

Defined in iLand\map_doc.js:45

Load a grid (provided in ESRI textformat) from disk. See landscape setup for information about projections.


  • file_name String


  • min_value
  • max_value

Defined in iLand\map_doc.js:59

Visualization of the map in the iLand Viewers' main window (if present). Map values are colorized between min_value (blue) and max_value (red).


  • min_value Double

    The minimum value for the color ramp in the visualization

  • max_value Double

    The minimum value for the color ramp in the visualization


  • name

Defined in iLand\map_doc.js:74

Registers the map with the user interface of iLand ( The map is added to the "Scripts" section of grids, and iLand renders it when clicking on it. Default value range is set to min/max values within the grid.


  • name String

    Name to use for the map in the UI. When blank, the file path is used (relative to the project folder)


// load a extra stand grid var extra_stand_grid = new Map(); extra_stand_grid.load(Globals.path('gis/stand_grid2.asc')); extra_stand_grid.registerUI();




Defined in iLand\map_doc.js:37

The filename for successfully loaded grid or 'invalid'.