@codewithvincent/react-native-gps-filter

Kalman-based adaptive GPS filter for React Native using Zustand and expo-location.

---

Features

• Smooth and adaptive GPS filtering with Kalman filter
• Supports both Expo (expo-location) and bare React Native (@react-native-community/geolocation) environments
• Provides a React hook powered by Zustand for state management
• Also provides a standalone class API for flexible, hook-less usage
• Adaptive thresholds based on user speed (stationary, walking, running, driving)
• Easy integration into any React Native app

---

Installation

1npm install @codewithvincent/react-native-gps-filter
2
3
4If you want to use the React hook, also install:
5
6npm install zustand
7
8
9
10
11Usage
12
131. React Hook API (requires Zustand)
14
15    This is the easiest way to integrate if you use React and Zustand in your app.
16
17
18    import React, { useEffect } from 'react';
19    import * as LocationExpo from 'expo-location';
20    import { useLocationStore } from '@codewithvincent/react-native-gps-filter';
21
22    export default function App() {
23    const filterAndAddLocation = useLocationStore(state => state.filterAndAddLocation);
24
25    useEffect(() => {
26        (async () => {
27        const { status } = await LocationExpo.requestForegroundPermissionsAsync();
28        if (status !== 'granted') {
29            console.error('Location permission denied');
30            return;
31        }
32
33        const subscription = await LocationExpo.watchPositionAsync(
34            { accuracy: LocationExpo.Accuracy.Highest, distanceInterval: 1 },
35            (location) => {
36            const result = filterAndAddLocation(location);
37            if (result.result) {
38                console.log('Filtered location:', result.predictedLocation);
39            }
40            }
41        );
42
43        return () => subscription.remove();
44        })();
45    }, []);
46
47    return null;
48    }
49
50
51
52
532. Class API (no Zustand needed)
54
55    Use this if you want to manage state yourself or avoid Zustand.
56
57
58    import { LocationFilter } from '@codewithvincent/react-native-gps-filter';
59
60    const filter = new LocationFilter();
61
62    async function onLocationUpdate(location) {
63    const result = filter.filterAndAddLocation(location);
64    if (result.result) {
65        console.log('Filtered Location:', result.predictedLocation);
66    }
67    }
68
69
70
71
72API
73    useLocationStore (Zustand Hook)
74
75        filterAndAddLocation(location: LocationObject, onPredictLocation?: (LocationObject) => void): FilterResult
76        Filters a raw location, returns filtering result.
77
78        resetFilters(): void
79        Resets internal Kalman filters and state.
80
81
82    LocationFilter Class
83
84        filterAndAddLocation(location: LocationObject, onPredictLocation?: (LocationObject) => void): FilterResult
85        Same as above but in class form for manual control.
86
87        resetFilters(): void
88        Resets internal filters and state.
89
90
91Notes
92    This package supports both Expo Managed and Bare React Native projects by auto-detecting environment to use the appropriate location API.
93
94    For best results, ensure location permissions are granted and GPS accuracy is high.
95
96
97License
98MIT © Vincent