inla.over_sp_mesh {INLA} | R Documentation

## Check which mesh triangles are inside a polygon

### Description

Wrapper for the `sp::over()` method to find triangle centroids or vertices inside `sp` polygon objects. since 23.06.06 in favour of `inlabru::fm_contains()` when `inlabru` version `⁠>= 2.7.0.9011⁠` is installed, and since 23.08.02 in favour of `fmesher::fm_contains()` when `fmesher`.

### Usage

    inla.over_sp_mesh(x, y, type = c("centroid", "vertex"), ignore.CRS = FALSE)

### Arguments

`x` | geometry (typically a `sp::SpatialPolygons()` object) for the queries
`y` | an `inla.mesh()` object
`type` | the query type; either `'centroid'` (default, for triangle centroids), or `'vertex'` (for mesh vertices)
`ignore.CRS` | logical; whether to ignore the coordinate system information in `x` and `y` (default `FALSE`)

### Value

A vector of triangle indices (when `type` is `'centroid'`) or vertex indices (when `type` is `'vertex'`)

### Author(s)

Haakon Bakka, bakka@r-inla.org, and Finn Lindgren finn.lindgren@gmail.com

### Examples

    if (require("sp", quietly = TRUE)) {
        # Create a polygon and a mesh
        obj <- sp::SpatialPolygons(
            list(sp::Polygons(
                list(sp::Polygon(rbind(
                    c(0, 0),
                    c(50, 0),
                    c(50, 50),
                    c(0, 50)
                ))),
                ID = 1
            )),
            proj4string = fmesher::fm_CRS("longlat_globe")
        )
        mesh <- inla.mesh.create(globe = 2, crs = fmesher::fm_CRS("sphere"))

        ## 3 vertices found in the polygon
        inla.over_sp_mesh(obj, mesh, type = "vertex")

        ## 3 triangles found in the polygon
        inla.over_sp_mesh(obj, mesh)

        ## Multiple transformations can lead to slightly different results due to edge cases
        ## 4 triangles found in the polygon
        inla.over_sp_mesh(
            obj,
            fmesher::fm_transform(mesh, crs = fmesher::fm_crs("mollweide_norm"))
        )
    }

[Package INLA version 25.06.07 Index]