feltr

The goal of feltr is to read maps from Felt as simple feature or SpatRaster objects.

Installation

You can install the development version of feltr like so:

pak::pkg_install("elipousson/feltr")

Example

library(feltr)

You can use read_felt_map() to create an sf object with features from a map URL.

url <- "https://felt.com/map/Site-Plan-Example-PGTipS2mT8CYBIVlyAm9BkD"

site_plan <- read_felt_map(url)

plot(site_plan)
#> Warning: plotting the first 9 out of 22 attributes; use max.plot = 22 to plot
#> all

get_felt_map() returns a list with basic information about a map (set read = TRUE to read map elements and layers at the same time):

get_felt_map(url)
#> $attributes
#> $attributes$title
#> [1] "Site Plan Example"
#> 
#> $attributes$url
#> [1] "https://felt.com/map/Site-Plan-Example-PGTipS2mT8CYBIVlyAm9BkD"
#> 
#> $attributes$thumbnail_url
#> [1] "https://d3a9fdbxbk3c9v.cloudfront.net/0fc919da-9654-4544-8acb-b9e74253fb3e.jpg"
#> 
#> 
#> $id
#> [1] "PGTipS2mT8CYBIVlyAm9BkD"
#> 
#> $links
#> $links$self
#> [1] "https://felt.com/api/v1/maps/PGTipS2mT8CYBIVlyAm9BkD"
#> 
#> 
#> $type
#> [1] "map"

You can also use read_felt_raster() (a wrapper for rasterpic::rasterpic_img()) to create a SpatRaster object from a “Image” type feature in Felt.

image_map <- read_felt_raster(
  "https://felt.com/map/feltr-sample-map-read-felt-raster-oiinodTbT79BEueYdGp1aND",
  "https://tile.loc.gov/image-services/iiif/service:gmd:gmd370:g3700:g3700:ct003955/full/pct:12.5/0/default.jpg"
)

image_map
#> class       : SpatRaster 
#> dimensions  : 655, 764, 3  (nrow, ncol, nlyr)
#> resolution  : 6439.813, 6439.813  (x, y)
#> extent      : -12209153, -7289135, 2474851, 6692929  (xmin, xmax, ymin, ymax)
#> coord. ref. : WGS 84 / Pseudo-Mercator (EPSG:3857) 
#> source      : file7bca6fa8700a.jpg 
#> colors RGB  : 1, 2, 3 
#> names       : file7bca6fa8700a_1, file7bca6fa8700a_2, file7bca6fa8700a_3

For more information on the Felt Public API check out the guide to Getting Started with the Felt API or the Felt Public API reference.

Note, in July 2024, Felt announced the pricing for subscription plans that are expected to limit API access to paid accounts starting in January 2024. Educators can also apply for free accounts to retain API access after January 2024.

Related Projects

• {feltr}: A R package with the same name that provide very similar functionality to this package.
• felt-upload: A Python package to upload data to Felt.
• Add to Felt QGIS Plugin: A QGIS plugin for uploading data to Felt.
• feltpy: A lightweight Python package to interact with the public API of Felt.com.