cell_to_line: Convert H3 cell indexes to a line

In obrl-soil/h3jsr: Access Uber's H3 Library

Convert H3 cell indexes to a line

Description

Return line geometry for a sequence of H3 cell indexes in WGS84 coordinates.

Usage

cell_to_line(input = NULL, simple = TRUE)

## S3 method for class 'data.frame'
cell_to_line(input = NULL, simple = TRUE)

## S3 method for class 'list'
cell_to_line(input = NULL, simple = TRUE)

## S3 method for class 'character'
cell_to_line(input = NULL, simple = TRUE)

Arguments

input	Character vector of 15-character indexes generated by H3, a list of such, or a data frame where the last column is a list-column of H3 cell indexes (usually the output of h3jsr::grid_path().
simple	Logical; whether to return an sfc_LINESTRING object or an sf data frame containing both inputs and outputs.

Value

An sfc_LINESTRING object containing a line for each vector of H3 cell indexes supplied. If simple = FALSE, an sf object including the input data.

Note

This function can accept any arbitrary vector of cell indexes (including cells at multiple resolutions) but results may be unexpected. It is assumed that indexes are supplied in a pre-ordered fashion.

Examples

# What is the cell index over the Brisbane Town Hall at resolution 10?
brisbane_hex_10 <- cell_to_polygon(input = '8abe8d12acaffff')

# Give me a some nearby cells
hex_sample <- get_disk_list('8abe8d12acaffff', 4)[[1]][[4]][seq(1,18,3)]
hex_sample_polys <- cell_to_polygon(hex_sample)

# find connecting paths
paths <- grid_path(rep('8abe8d12acaffff', 6), hex_sample)

# make lines
lines <- cell_to_line(paths)

## Not run: 
plot(hex_sample_polys, reset = FALSE)
plot(brisbane_hex_10, add = TRUE)
plot(lines, col = 'red', add = TRUE)

## End(Not run)

obrl-soil/h3jsr documentation built on Jan. 27, 2024, 4:33 a.m.