getbyattrib

getbyattrib(D::Vector{<:GMTdataset}[, index::Bool=false]; kw...)

or

filter(D::Vector{<:GMTdataset}; kw...)

or

findall(D::Vector{<:GMTdataset}; kw...)

Take a GMTdataset vector and return only its elements that match the condition(s) set by the kw keywords. Note, this assumes that D has its attrib fields set with usable information.

NOTE: Instead of getbyattrib one can use instead filter (…, index=false) or findall (…, index=true)

• attrib name(s)=value(s): Easier to explain by examples: NAME="Antioquia", select all elements that have that attribute/value combination. NAME=("Antioquia", "Caldas"), picks elements that have those NAME attributes. Add as many as wished. If using two kwargs the second works as a condition. (..., NAME=("Antioquia", "Caldas"), feature_id=0) means select all elements from Antioquia and Caldas that have the attribute feature_id = 0.

  A second set of attributes can be used to select elements by region, number of polygon vertices and area. For that, name the keyword with a leading underscore, e.g. _region, _nps, _area, _unique. Their values are passed respectively a 4 elements tuple and numbers. E.g. _region=(-8.0, -7.0, 37.0, 38.0), _nps=100, _area=10, _aspect=0.5. Areas are in square km when input is in geographic coordinates, otherwise square data units. The aspect ratio passed to the _aspect option is width/height of the bounding box, not of the polygon itself. Values <= 1, == 1 and >= 1 select polygons with aspect ratios less than, equal to and greater than the specified value. The _unique case is a bit special and is meant to be used when more than one polygon share the same attribute value (e.g. countries with islands). In that case, set the value of _unique to the name of the attribute that is shared by the polygons (e.g. _unique="NAME"). By default (e.g. _unique=true), the attribute name is Feature_ID which is the one used by GMT when creating unique IDs for polygons read from OGR formats (.shp, .geojson, etc). If this attrib name is not found, we search for CODE which is the one assigned by GMT when extracting polygons from the internal GMT coasts database. If none of these is found, it is users responsibility to provide a valid attribute name. The uniqueness is determined by selecting the polygon with the largest area.

• attrib or att: (OLD SYNTAX) A NamedTuple with the attribname, attribvalue as in att=(NAME_2="value",). Use more elements if wishing to do a composite match. E.g. att=(NAME_1="val1", NAME_2="val2") in which case only segments matching the two conditions are returned.

• index: Use this positional argument = true to return only the segment indices that match the att condition(s).

Returns

Either a vector of GMTdataset, or a vector of Int with the indices of the segments that match th query condition. Or nothing if the query results in an empty GMTdataset

Examples

D = filter(D, NAME_2="Porto");

D = filter(D, _region="(-8.0, -7.0, 37.0, 38.0)", _nps=100);

See Also

inwhichpolygon, polygonlevels

Source Code

This function has multiple methods:

• getbyattrib(D::Vector{<:GMTdataset}; indices, kw...) - spatial_funs.jl:341
• getbyattrib(D::Vector{<:GMTdataset}, ind_::Bool; kw...) - spatial_funs.jl:213