Query a SpatVectorProxy to extract a subset

query

Methods for spatial data analysis with vector (points, lines, polygons) and raster (grid) data. Methods for vector data include geometric operations such as intersect and buffer. Raster methods include local, focal, global, zonal and geometric operations. The predict and interpolate methods facilitate the use of regression type (interpolation, machine learning) models for spatial prediction, including with satellite remote sensing data. Processing of very large files is supported. See the manual and tutorials on <https://rspatial.org/> to get started.

Robert Hijmans

terra

Spatial Data Analysis

Robert J. Hijmans

Andrew Brown

Márcia Barbosa

Roger Bivand

Michael Chirico

Emanuele Cordano

Krzysztof Dyba

Edzer Pebesma

Barry Rowlingson

Michael D. Sumner

query function

Query a SpatVectorProxy object — query

<dl>

<dt>x</dt>
<dd>SpatVectorProxy</dd>

<dt>start</dt>
<dd>positive integer. The record to start reading at</dd>

<dt>n</dt>
<dd>positive integer. The number of records requested</dd>

<dt>vars</dt>
<dd>character. Variable names. Must be a subset of <code>names(x)</code></dd>

<dt>where</dt>
<dd>character. expression like "NAME_1='California' AND ID &gt; 3" , to subset records. Note that start and n are applied after executing the where statement</dd>

<dt>extent</dt>
<dd>Spat* object. The extent of the object is used as a spatial filter to select the geometries to read. Ignored if <code>filter</code> is not <code>NULL</code></dd>

<dt>filter</dt>
<dd>SpatVector. Used as a spatial filter to select geometries to read (the convex hull is used for lines or points)</dd>

<dt>sql</dt>
<dd>character. Arbitrary SQL statement. If used, arguments "start", "n", "vars" and "where" are ignored</dd>

<dt>what</dt>
<dd>character indicating what to read. Either <code>""</code> for geometries and attributes, or <code>"geoms"</code> to only read the geometries, <code>"attributes"</code> to only read the attributes (that are returned as a data.frame)</dd>

<dt>dialect</dt>
<dd>character. The SQL dialect to use (if any). For example: "SQLite"</dd>

</dl>

Arguments

Query a SpatVectorProxy object

query: Query a SpatVectorProxy object

Description

Usage

Arguments

Value

See Also

Examples