Add Trahan trip route

layers/index.js

@@ -13,6 +13,7 @@ import national_land from './national-land/index.js';
 import cellular from './cellular.js';
 import light_pollution from './light_pollution.js';
 import state_land from './state-land/index.js';
+import trips from './trips/index.js';
 
 const layerCategories = [
     { // Base maps
@@ -76,6 +77,7 @@ const layerCategories = [
             },
         ]
     },
+    trips,
     chains,
     census_bureau,
     states,

layers/trips/index.js

@@ -0,0 +1,13 @@
+import ncAug2023 from './trahan-north-carolina-august-2023/layer.js'
+
+const trips = {
+    name: "Trips",
+    layers: [
+        {
+            name: "North Carolina 2023-08 with Trahans",
+            layer: ncAug2023,
+        },
+    ],
+};
+
+export default trips;

layers/trips/trahan-north-carolina-august-2023/get_data.sh

@@ -0,0 +1,9 @@
+#!/bin/sh
+
+FROM="2023-08-24T12:45:00.000Z"
+TO="2023-09-01T21:50:00.000Z"
+URL="https://whereis.chandlerswift.com/api/0/locations?from=$FROM&to=$TO&format=geojson&user=chandler&device=oneplus6t"
+
+curl --silent "$URL" \
+    | python "$(dirname $0)/../../../util/process_owntracks_geojson_to_line.py" \
+    > data.geojson

layers/trips/trahan-north-carolina-august-2023/layer.js

@@ -0,0 +1,26 @@
+import VectorLayer from 'ol/layer/Vector';
+import {Vector as VectorSource} from 'ol/source.js';
+import GeoJSON from 'ol/format/GeoJSON.js';
+
+import {Style, Stroke} from 'ol/style.js';
+
+import url from './data.geojson?url'; // TODO: remove `?url`?
+
+const colors = '135, 0, 226'; // Käthe says lavender
+
+const vectorLayer = new VectorLayer({
+    source: new VectorSource({
+        url: url,
+        format: new GeoJSON,
+    }),
+    style: function(feature, resolution){
+        return new Style({
+            stroke: new Stroke({
+                color: `rgba(${colors},${Math.min(1, Math.pow(resolution/10, 1/4))})`,
+                width: 10/Math.pow(resolution, 1/4),
+            })
+        });
+    },
+});
+
+export default vectorLayer;

util/process_owntracks_geojson_to_line.py

@@ -0,0 +1,41 @@
+#!/usr/bin/python3
+
+import json
+import math
+import sys
+
+# https://stackoverflow.com/a/19412565
+# returns distance in kilometers
+def distance(lat1, lon1, lat2, lon2):
+    R = 6373.0 # Approximate radius of earth in km
+
+    lat1 = math.radians(52.2296756)
+    lon1 = math.radians(21.0122287)
+    lat2 = math.radians(52.406374)
+    lon2 = math.radians(16.9251681)
+
+    dlon = lon2 - lon1
+    dlat = lat2 - lat1
+
+    a = math.sin(dlat / 2)**2 + math.cos(lat1) * math.cos(lat2) * math.sin(dlon / 2)**2
+    c = 2 * math.atan2(math.sqrt(a), math.sqrt(1 - a))
+
+    return R * c
+
+data = json.load(sys.stdin)
+
+coordinates = []
+
+for feature in data['features']:
+    if feature['properties']['acc'] < 500:
+        coordinates.append(feature['geometry']['coordinates'])
+    # TODO: auto prune unnecessary points (e.g. too close to previous points?)
+
+print(json.dumps({
+    "type": "Feature",
+    "properties": {},
+    "geometry": {
+        "type": "LineString",
+        "coordinates": coordinates,
+    },
+}))