Fuzzy Geometries SUFF Software

This repo is for the software implementation of the SUFF model in JavaScript, which will be an NPM package as well as an online test UI, available here - suff.idnau.org (yet to be deployed).

Table of Contents

• The SUFF Model
• Installation
  • NPM Package
  • Test UI
• Usage
  • NPM Package
  • Test UI
• Implementation
• Copyright and License
• Contact

The SUFF Model

The Spatial Uncertainty for Features & Functions (SUFF) model is a new cutting-edge model to be included in GeoSPARQL 1.3 which provides a way to describe spatial uncertainty in data.

Features in the SUFF model fit into one of three levels of measurement (see diagram below):

• Nominal: No order specified
• Ordinal: Order specified with no certainty values
• "Numeric": Order and certainty values specified, optionally provide 0 & 1 certainty geometries

Credit: Nicholas Car - https://w3id.org/suff/

Example of a SUFF feature in RDF:

PREFIX geo: <http://www.opengis.net/ont/geosparql#>
PREFIX rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX sdo: <https://schema.org/>
PREFIX suff: <http://w3id.org/suff/>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

<https://example.com/feature/feature1>
    a geo:Feature ;
    sdo:name "Test SUFF feature" ;
    geo:hasGeometry [
        a geo:GeometryCollection ;
        rdfs:_1 [
            a geo:Geometry ;
            geo:asWKT "POLYGON ((...))"^^geo:wktLiteral ;
            rdf:value "0.3"^^xsd:double ;
        ] ;
        rdfs:_2 [
            a geo:Geometry ;
            geo:asWKT "POLYGON ((...))"^^geo:wktLiteral ;
            rdf:value "0.5"^^xsd:double ;
        ] ;
        rdfs:_3 [
            a geo:Geometry ;
            geo:asWKT "POLYGON ((...))"^^geo:wktLiteral ;
            rdf:value "0.8"^^xsd:double ;
        ] ;
    ];
.

Installation

NPM Package

To install, run the following using your favourite npm package manager (not yet published):

pnpm add suff

or

yarn add suff

or

npm install suff

Test UI

This project uses PNPM, so ensure that's installed first. Clone this repo then run the following at the project root directory to install the test UI application on your machine:

pnpm install

Usage

NPM Package

An example of importing & using the SUFF package using the blur function:

import { blur } from "suff";

const rdfDataStr = "...";

const geometries = blur(rdfDataStr);

Functions available from the NPM package (TBD):

• generate() - for generating 0 & 1 geometries
• convert() - for converting SUFF RDF to GeoJSON
  • option for plain GeoJSON (1 feature with multiple geometries)
  • option for map-friendly GeoJSON (1 feature per geometry)
• blur() - for generating contours for blurring with a contour count parameter

Test UI

Run the following to run a dev server for the test UI application:

cd suff-rdf
pnpm build
cd ../suff-test
pnpm dev

Software Implementation

1. determine case - nominal, ordinal or "numeric"
2. convert to geojson
3. create 0 & 1 geometries if applicable
4. convert geoms to points and create TIN network
5. sample point grid from TIN network
6. create contours from point grid
7. display a large number of contours with opacity to visualise blurring

Copyright and License

© Indigenous Data Network 2024. This software is licensed for reuse using the BSD 3-Clause license.

Contact

Jamie Feiss
Data Infrastructure Developer
Indigenous Data Network
University of Melbourne
jamie.feiss@unimelb.edu.au