The iLand Javascript API The iLand Javascript API

  • API Docs for Version: 1.0

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    SaplingList Class

    Defined in: ABE\saplinglist_doc.js:2
    Module: ABE

    The SaplingList class represents a list of saplings (=cohort of trees <4m height) that can be manipulated (e.g., removed) with functions of the class.

    Overview

    initializing the list

    The object is available automatically when using the Bite-submodule.

    SaplingList can also be used as a standalone object, but in this case populating the sapling list needs to be done by the user with functions such loadFromStand().

    Example

    var saps = new SaplingList; // create a SaplingList object
saps.loadFromStand(123); // load saplings of stand 123
saps.kill(); // and be nasty

    manipulating the content of the list

    The list of sapling cohorts may be manipulated using functions such as filter(). There are functions helping to get aggregate values (sum()).

    manipulationg saplings

    The class provides function to kill cohorts (kill()) or to modify cohorts (e.g. browse()).

    Variables

    A list of available variables for saplings: https://iland-model.org/sapling+variables

    general notes

    The sapling list heavily used the expression engine of iLand https://iland-model.org/Expression. Expressions are provided as strings to the respective Javascript functions (e.g.,filter) and evaluated by iLand. Note that tree species names are treated as a special case (https://iland-model.org/Expression#Constants).

    Example

    var saplings = biteAgent.cell(0,0).saplings; // currently, only available via Bite
// load of saplings in Bite: bitecell.reloadSaplings();

saplings.filter('height > 2'); // keep only larger cohorts
trees.sum('foliagemass*nrep'); // calculate total leaf mass of all trees in a cohort
saplings.browse(); // affect saplings (browsing: reduced height growth)

    Item Index

    Methods

    Properties

    Methods

    browse

    (
    • do_browse
    )
    Integer

    Defined in ABE\saplinglist_doc.js:86

    Affect all saplings in the list by browsing; this reduces the height growth in the current year to 0.

    Parameters:

    • do_browse Boolean

      if true, the cohorts are marked as browsed (false unmarks cohorts)

    Returns:

    Integer:

    the number of trees that have been removed.

    Example:

    saplings.browse(); // browse saplings

    clear

    ()

    Defined in ABE\saplinglist_doc.js:60

    Clear the list without affecting the saplings in the list. Note that explcitly clearing the list is usually not necessary (e.g. when using loadFromStand() )

    Example:

    saplings.clear(); // empty lsit
                    console.log(saplings.count); // -> 0

    filter

    (
    • filter
    )
    Integer

    Defined in ABE\saplinglist_doc.js:96

    Apply a filter on the list. Only saplings for which the filter condition filter evaluates to true, remain in the list.

    Parameters:

    • filter String

      A valid filter Expression.

    Returns:

    Integer:

    the number of trees that remain in the list.

    Example:

    saplings.filter('species=fasy'); // remove all trees that are not Beech
                    trees.filter('incsum(foliagemass*nrep)<1'); // max foliage mass after filtering 1kg

    kill

    (
    • filter
    )
    Integer

    Defined in ABE\saplinglist_doc.js:49

    Kill (i.e., cut down and do not remove from the forest) the saplings in the list, filtered with filter. If filter is omitted, all saplings are killed.

    Parameters:

    • filter String

      A valid filter Expression.

    Returns:

    Integer:

    the number of trees that have been removed.

    Example:

    saplings.kill('age<5'); // kill young saplings

    loadFromStand

    (
    • standId
    • filter
    • do_append
    )
    Integer

    Defined in ABE\saplinglist_doc.js:69

    Load all (or a subset) of sapling that are located on the stand denoted by standId. The filter let you control which saplings should be loaded. Control with do_append whether the list should be cleared before loading saplings.

    Parameters:

    • standId Integer

      A numeric standId that refers to the stand-grid of iLand.

    • filter String

      A valid filter Expression (see above), can be omitted

    • do_append Bool

      if true, saplings are added to the list without clearing the list first. Default is false (list is cleared). Can be omitted.

    Returns:

    Integer:

    the number of trees that have been loaded.

    Example:

    saplings.loadFromStand(123, 'species=fasy'); // load all beech saplings of stand 123
                    
                    saplings.loadFromStand(124, 'true', true); // append (all) saplings from stand 124

    sum

    (
    • expr
    • filter
    )
    Double

    Defined in ABE\saplinglist_doc.js:108

    Calculates the sum of a given expr that can contain any of the available sapling variables. The optional filter is another expression that filters the trees that are processed. Returns the sum of expr.

    Note: counting saplings that fulfill the filter expression can be expressed as: sum('1', '<filter-expr>').

    Parameters:

    • expr String

      a valid expression that should be processed

    • filter String

      only saplings that pass the filter are processed

    Returns:

    Double:

    the sum over the value of exprof the population

    Example:

    console.log('number of repr. trees: ' + saplings.sum('nrep') ); // just a count, same as saplings.length
                    console.log('cohorts > 1m: ' + trees.sum('1', 'height>1') ); // note that '1' is a string (and parsed by the expression engine)

    Properties

    count

    Integer

    Defined in ABE\saplinglist_doc.js:42

    the number of cohorts that are currently loaded in the list.