https://github.com/JosiahParry/geohash

https://github.com/JosiahParry/geohash

Last synced: 23 days ago
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• Host: GitHub
• URL: https://github.com/JosiahParry/geohash
• Owner: JosiahParry
• License: other
• Created: 2024-04-21T16:57:45.000Z (about 1 year ago)
• Default Branch: main
• Last Pushed: 2024-10-23T15:35:48.000Z (6 months ago)
• Last Synced: 2025-03-24T16:02:42.412Z (about 1 month ago)
• Language: R
• Size: 1.4 MB
• Stars: 9
• Watchers: 1
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.Rmd
  • License: LICENSE

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• jimsghstars - JosiahParry/geohash - (R)

README

        
---

output: github_document

format: gfm

---

```{r, include = FALSE}

knitr::opts_chunk$set(

  collapse = TRUE,

  comment = "#>",

  fig.path = "man/figures/README-",

  out.width = "100%"

)

```

# geohash

`{geohash}` is an R package to provide geohash encoding and decoding. It is based on the [Rust crate geohash](https://docs.rs/geohash). This package is actively under development.

You can watch me create this package in my [YouTube video](https://youtu.be/yaxfqpECIZ0).

There is a good chance you do not need to use this package. The package `{geohashTools}` is faster in almost every case.

This package serves as an example of how to use R and Rust together.

## Installation

You can install the development version of geohash like so:

``` r

if (!requireNamespace("remotes")) install.packages("remotes")

remotes::install_github("josiahparry/geohash")

```

## Example

Encode x and y coordinates as a geoash using `encode()` 

```{r include = FALSE}

set.seed(0)

library(pillar)

library(sf)

```

```{r}

library(geohash)

# create random x & y points

n <- 5

x <- runif(n, -180, 180)

y <- runif(n, -90, 90)

gh <- encode(x, y, 8)

gh

```

The geohashes can be decoded using `decode()` which provides you with their center, and the error in both the x and y directions. 

```{r}

decode(gh)

```

Additionally, you can extract the bounding box of the geohashes using `decode_bbox()`. This returns a `bbox` object from the `sf` package. 

```{r}

bboxes <- decode_bbox(gh) 

bboxes

```

You can use these bounding boxes to create an `sfc` of polygons. 

```{r}

do.call(c, lapply(bboxes, sf::st_as_sfc))

```

Alternatively, you can identify the neighboring geohash cells using `neighbor()` and `neighbors()` function. The `neighbor()` function identifies a single neighbor based on a direction whereas `neighbors()` provides all adjacent geohashes. 

Here we can find the neighbors to the north and south-east.

```{r}

neighbor(gh, "n")

neighbor(gh, "se")

```

We can also find _all_ adjacent neighbors.

```{r}

neighbors(gh)

```

## Benchmarks 

```{r}

n <- 1e6

x <- runif(n, -180, 180)

y <- runif(n, -90, 90)

bench::mark(

  geohash = geohash::encode(x, y, 8L),

  geohash_par = geohash::encode_par(x, y, 8L),

  geohashTools = geohashTools::gh_encode(y, x, 8L),

  iterations = 10

)

bench::mark(

  geohash = geohash::neighbors(gh),

  geohashTools = geohashTools::gh_neighbors(gh),

  check = FALSE

)

bench::mark(

  geohash = geohash::decode(gh),

  geohashTools = geohashTools::gh_decode(gh, TRUE),

  check = FALSE

)

```