How to get/set weights for a supervised model in tensorflow.js? - tensorflow

I'd like to change the weights of a supervised model but I get the same exact result after changing the weights. What am I doing wrong?
const model = tf.sequential();
model.add(tf.layers.dense({...}));
model.add(tf.layers.dense({...}));
model.add(tf.layers.dense({...}));
model.compile({...});
model.fit({});
const result1 = model.predict(tf.tensor2d(...)).dataSync();
const newWeights = [];
model.layers.map((layer, i) => {
newWeights[i] = []
const weights = layer.getWeights();
newWeights[i][0] = weights[0].arraySync()
newWeights[i][1] = weights[1].arraySync()
newWeights[i][0].map(tensor => tensor.map(x => {
if (random(1) < 0.5) {
return x + offset();
}
return x;
})
layer.setWeights([tf.tensor2d(newWeights[i][0], [newWeights[i][0].length, newWeights[i][0][0].length]), tf.tensor(newWeights[i][1])])
})
const result2 = model.predict(tf.tensor2d(...)).dataSync();
Code snippets:
const random = (max) => {
return floor(Math.random() * Math.floor(max), 2);
}
const floor = (num, toDecimal) => {
let dec = Math.pow(10, toDecimal);
return Number(Math.floor(num * dec) / dec);
}
const offset = () => {
randomGaussian() * 0.5
}
let previous = false;
let y2 = 0;
const randomGaussian = (mean, sd) => {
let y1, x1, x2, w;
if (previous) {
y1 = y2;
previous = false;
} else {
do {
x1 = random(2) - 1;
x2 = random(2) - 1;
w = x1 * x1 + x2 * x2;
} while (w >= 1);
w = Math.sqrt(-2 * Math.log(w) / w);
y1 = x1 * w;
y2 = x2 * w;
previous = true;
}
let m = mean || 0;
let s = sd || 1;
return y1 * s + m;
};
result1 === result2 but why?

Most likely that the new weights are identical to that of the first model.
Example: Simple example to change weights of a model
(async() => {
const model = tf.sequential({
layers: [tf.layers.dense({units: 1, inputShape: [10]})]
});
model.compile({optimizer: 'sgd', loss: 'meanSquaredError'});
for (let i = 1; i < 5 ; ++i) {
const h = await model.fit(tf.ones([8, 10]), tf.ones([8, 1]), {
batchSize: 4,
epochs: 3
});
console.log("Loss after Epoch " + i + " : " + h.history.loss[0]);
}
const p = await model.predict(tf.zeros([1, 10]))
p.print()
const layers = model.layers
layers[0].setWeights([tf.zeros([10, 1]), tf.zeros([1])])
const q = await model.predict(tf.zeros([1, 10]))
q.print()
})()
<html>
<head>
<!-- Load TensorFlow.js -->
<script src="https://cdn.jsdelivr.net/npm/#tensorflow/tfjs#latest"> </script>
</head>
<body>
</body>
</html>
Issue of the code
The newWeights created is not assigned to newWeights. map is not an in-place operator. The array returned by map should be assigned back to newWeights.
newWeights[i][0] = newWeights[i][0].map(tensor => tensor.map(x => {
if (random(1) < 0.5) {
return x + offset();
}
return x;
})

Related

SVGPointList length changes using svg.js

Hi I am using the function createPoint to animate a polygon using gsap. I am also using svg.js
If I use vanilla javascript to get the points of the svg with
var polygon = document.querySelector("polygon");
var points = polygon.points;
it returns 3 points which correspond to the number of times the createPoint function is run. This logs out as:
0: SVGPoint {x: 105.30396270751953, y: 143.0928955078125}
1: SVGPoint {x: 348.09027099609375, y: 97.7249984741211}
2: SVGPoint {x: 276.54010009765625, y: 327.56372070}
If I use the svg.js code
const draw = SVG().addTo('body')
var svg = draw.node;
const polygon = draw.polygon().node;
var points = polygon.points;
the same function logs a list of 4 SVGPoints with the first point being {x:0,y:0} even though I am only running the function 3 times. Where is the additional (index 0) svg point coming from? Thanks in advance
0: SVGPoint {x: 0, y: 0}
1: SVGPoint {x: 93.79865264892578, y: 124.19292449951172}
2: SVGPoint {x: 346.3572082519531, y: 97.5942153930664}
3: SVGPoint {x: 227.08517456054688, y: 269.97042846
given the following html
<svg>
<polygon points="">
</svg>
And the code below
TweenLite.defaultEase = Sine.easeInOut;
const draw = SVG().addTo('body')
var svg = draw.node;
const polygon = draw.polygon().node;
var points = polygon.points;
console.log('points',points)
var offset = 75;
createPoint(100, 100);
createPoint(300, 100);
createPoint(300, 300);
// createPoint(100, 300);
function createPoint(x, y) {
var minX = x - offset;
var maxX = x + offset;
var minY = y - offset;
var maxY = y + offset;
var point = points.appendItem(svg.createSVGPoint());
point.x = x;
point.y = y;
moveX();
moveY();
function moveX() {
TweenLite.to(point, random(2, 4), {
x: random(minX, maxX),
delay: random(0.5),
onComplete: moveX
});
}
function moveY() {
TweenLite.to(point, random(2, 4), {
y: random(minY, maxY),
delay: random(0.5),
onComplete: moveY
});
}
}
function random(min, max) {
if (max == null) { max = min; min = 0; }
if (min > max) { var tmp = min; min = max; max = tmp; }
return min + (max - min) * Math.random();
}
Just found out that by adding an empty array to the polygon i.e
const polygon = draw.polygon([]).node
it removes the default {x:0,y:0} object. Dont ask me why :)

Why does the Tensorflow JS model not learn?

I have build a model with tfjs based on the IRIS Classification example. After I removed the third label the AI doesn't work anymore and it's Loss and Accuracy lock at 4.6 and 0.5. Also the prediction after training are after the removing of the third label wrong. I think, that maybe the Loss function, the optimizer or the metrics are wrong for this type of AI.
Any Suggestions, what could be wrong with this model?
Code Information:
Data example: [24, 10, 20, 10, 1] (The first four numbers stand for an Outfit and the last digit stand for the rating)
Label before removing: [0 = bad rating, 1 = good rating, 2 = no opinion]
Label after removing: [0 = bad rating, 1 = good rating]
Optimizer: RMSProp
Loss function: categoricalCrossentropy
Metrics: accuracy
Learning Rate: 0.1
Epochs: 100
The Outfit is changed to a oneHot encoding
InputShape: [null, 4, 27]
OutputShape: [null, 2]
Modell Summary:
_________________________________________________________________
Layer (type) Output shape Param #
=================================================================
dense_Dense1 (Dense) [null,4,10] 280
_________________________________________________________________
flatten_Flatten1 (Flatten) [null,40] 0
_________________________________________________________________
dense_Dense2 (Dense) [null,2] 82
=================================================================
Total params: 362
Trainable params: 362
Non-trainable params: 0
_________________________________________________________________
My Code after removing
const stringdata = document.getElementById('stringdata').innerHTML;
console.log(string(stringdata));
const IRIS_DATA = string(stringdata);
const kleidungo = document.getElementById('kleidungo').innerHTML;
const kleidungu = document.getElementById('kleidungu').innerHTML;
const Kleidung = [string(kleidungo), string(kleidungu)];
console.log(Kleidung);
import { string } from './js.js';
import * as tfVis from 'https://cdn.jsdelivr.net/npm/#tensorflow/tfjs-vis';
async function ki() {
const IRIS_CLASSES = ['Bad', 'Good'];
const IRIS_NUM_CLASSES = IRIS_CLASSES.length;
var epochsnum = 0;
console.log(tfVis); // [object Module] { ... }
function doPrediction(model, xTest, yTest) {
const labels = yTest.argMax([-1]);
const preds = model.predict(xTest).argMax([-1]);
xTest.dispose();
return [preds, labels];
}
async function calculateAndDrawConfusionMatrix(model, xTest, yTest) {
const [preds, labels] = doPrediction(model, xTest, yTest);
const confusionMatrix = await tfvis.metrics.confusionMatrix(labels, preds);
const container = document.getElementById('confusion-matrix');
tfvis.render.confusionMatrix(container, {
values: confusionMatrix,
tickLabels: IRIS_CLASSES
});
labels.dispose();
}
function convertToTensors(data, targets, testSplit) {
const numExamples = data.length;
if (numExamples !== targets.length) {
throw new Error('data and split have different numbers of examples');
}
// Randomly shuffle `data` and `targets`.
const indices = [];
for (let i = 0; i < numExamples; ++i) {
indices.push(i);
}
tf.util.shuffle(indices);
const shuffledData = [];
const shuffledTargets = [];
for (let i = 0; i < numExamples; ++i) {
shuffledData.push(data[indices[i]]);
shuffledTargets.push(targets[indices[i]]);
}
// Split the data into a training set and a tet set, based on `testSplit`.
const numTestExamples = Math.round(numExamples * testSplit);
const numTrainExamples = numExamples - numTestExamples;
const xDims = shuffledData[0].length;
// Create a `tf.Tensor` to hold the feature data.
//var dataByClass = tf.oneHot(dataByClass2, 27);
const xs = tf.oneHot(shuffledData, 27);
// Create a 1D `tf.Tensor` to hold the labels, and convert the number label
// from the set {0, 1, 2} into one-hot encoding (.e.g., 0 --> [1, 0, 0]).
const ys = tf.oneHot(tf.tensor1d(shuffledTargets).toInt(), IRIS_NUM_CLASSES);
// Split the data into training and test sets, using `slice`.
const xTrain = xs.slice([0, 0], [numTrainExamples, xDims]);
const xTest = xs.slice([numTrainExamples, 0], [numTestExamples, xDims]);
const yTrain = ys.slice([0, 0], [numTrainExamples, IRIS_NUM_CLASSES]);
const yTest = ys.slice([0, 0], [numTestExamples, IRIS_NUM_CLASSES]);
return [xTrain, yTrain, xTest, yTest];
}
function getIrisData(testSplit) {
return tf.tidy(() => {
const dataByClass = [];
const targetsByClass = [];
for (let i = 0; i < IRIS_CLASSES.length; ++i) {
dataByClass.push([]);
targetsByClass.push([]);
}
for (const example of IRIS_DATA) {
const target = example[example.length - 1];
const data = example.slice(0, example.length - 1);
dataByClass[target].push(data);
targetsByClass[target].push(target);
}
const xTrains = [];
const yTrains = [];
const xTests = [];
const yTests = [];
for (let i = 0; i < IRIS_CLASSES.length; ++i) {
const [xTrain, yTrain, xTest, yTest] =
convertToTensors(dataByClass[i], targetsByClass[i], testSplit);
xTrains.push(xTrain);
yTrains.push(yTrain);
xTests.push(xTest);
yTests.push(yTest);
}
const concatAxis = 0;
return [
tf.concat(xTrains, concatAxis), tf.concat(yTrains, concatAxis),
tf.concat(xTests, concatAxis), tf.concat(yTests, concatAxis)
];
});
}
function loadTrainParametersFromUI() {
return {
epochs: 100,
learningRate: 0.1
};
}
async function trainModel(xTrain, yTrain, xTest, yTest) {
document.getElementById('Epochs').innerHTML = 'Model is create...';
const params = loadTrainParametersFromUI();
console.log('Shape: ' + xTrain.shape + '\n Data:')
xTrain.print();
console.log('Shape: ' + yTrain.shape + '\n Data:')
yTrain.print();
// Define the topology of the model: two dense layers.
const model = tf.sequential();
model.add(tf.layers.dense(
{
units: 10,
activation: 'sigmoid',
inputShape: [
xTrain.shape[1],
xTrain.shape[2]
]
}
));
model.add(
tf.layers.flatten()
);
model.add(tf.layers.dense(
{
units: 2,
activation: 'softmax'
}
));
model.summary();
const opti = "rmsprop";
const optimizer = tf.train.rmsprop(params.learningRate);
model.compile(
{
optimizer: optimizer,
loss: 'categoricalCrossentropy',
metrics: ['accuracy'],
}
);
const trainLogs = [];
const lossContainer = document.getElementById('lossCanvas');
const accContainer = document.getElementById('accuracyCanvas');
const beginMs = performance.now();
console.log('epochs: ' + params.epochs + ', lr: ' + params.learningRate + ', opti: ' + opti);
// Call `model.fit` to train the model.
const surface = {
name: 'show.fitCallbacks',
tab: 'Training'
};
//Train with callback after each epoh -> Diagramm
const history = await model.fit(xTrain, yTrain, {
epochs: params.epochs,
validationData: [xTest, yTest],
callbacks: {
onEpochEnd: async (epoch, logs) => {
// Plot the loss and accuracy values at the end of every training epoch.
const secPerEpoch = (performance.now() - beginMs) / (1000 * (epoch + 1));
trainLogs.push(logs);
epochsnum++;
document.getElementById('Epochs').innerHTML = (
'Epoche ' + epochsnum + "/" + params.epochs + '<br>Dauer der letzten Epoche: '+ secPerEpoch.toFixed(5) + 's <br> Verstrichene Zeit: ' + ((performance.now() - beginMs) / 1000).toFixed(5) + 's'
);
document.getElementById('Progressbar').innerHTML = (
'<progress id="progress" value="' + epochsnum + '" max="' + params.epochs + '"> ' + epochsnum + '% </progress>'
);
console.log(epochsnum + '. Epoche');
console.log('Epochendauer der Epoche ' + epochsnum + ': ' + secPerEpoch.toFixed(5));
console.log('Loss ', trainLogs[epochsnum-1].loss.toFixed(5));
console.log('Accuracy ', trainLogs[epochsnum-1].acc.toFixed(5));
tfvis.show.history(
lossContainer,
trainLogs,
['loss']
);
tfvis.show.history(
accContainer,
trainLogs,
['acc']
);
},
},
});
//Data Output
async function calculateAndDrawConfusionMatrix(model, xTest, yTest) {
const [preds, labels] = tf.tidy(() => {
const preds = model.predict(xTest).argMax(-1);
const labels = yTest.argMax(-1);
return [preds, labels];
});
const confMatrixData = await tfvis.metrics.confusionMatrix(labels, preds);
const container = document.getElementById('confusion-matrix');
tfvis.render.confusionMatrix(
container,
{
values: confMatrixData,
labels: IRIS_CLASSES
},
{
shadeDiagonal: true
},
);
tf.dispose([
preds,
labels
]);
}
calculateAndDrawConfusionMatrix(model, xTest, yTest);
const secPerEpoch = (performance.now() - beginMs) / (1000 * params.epochs);
console.log((performance.now() - beginMs) / 1000);
console.log(secPerEpoch);
document.getElementById('Epochs').innerHTML = '';
document.getElementById('Progressbar').innerHTML = '';
var time = ((performance.now() - beginMs) / 1000).toFixed(5);
document.getElementById('secperEpochs').innerHTML = (
'Durchschnittliche Dauer einer Epoche: ' + secPerEpoch.toFixed(5) + ' Sekunden <br> Gesamte Dauer: ' + time + 's'
);
//Predict Test
console.log('predict [2, 2, 14, 1]' + model.predict(
tf.oneHot(
[[2, 2, 14, 1]],
27
)
));
var predict = model.predict(
tf.oneHot(
[[2, 2, 14, 1]],
27
)
);
document.getElementById('Predict').innerHTML = predict;
console.log("===================================");
console.log('xTest ' + xTest);
console.log('Predict ' + model.predict(xTest));
console.log("===================================");
function TensortoArray(id) {
var predictneu = document.getElementById(id).innerHTML;
var predict2 = predictneu.replace("Tensor", "");
predict2 = predict2.split(",");
var predict2neu = predict2.pop();
var predict21 = predict2[0];
predict21 = predict21.replace("[", "");
predict21 = predict21.replace("[", "");
predict21 = predict21.replace("\n", "");
var predict2neu = predict2.shift();
var predict2neu = predict2.unshift(predict21);
var arraytensor = [];
predict2.forEach(element => {
var inserrrt = parseFloat(element);
arraytensor.push(inserrrt);
});
console.log('ArrayTensor ' + arraytensor);
var arrayten = [];
arraytensor.forEach(element => {
var a1 = arrayten.push(element.toFixed(5)*100);
});
return arrayten;
}
var arraytensor = TensortoArray('Predict');
if (arraytensor[0]>arraytensor[1]) {
console.log(IRIS_CLASSES[0])
document.getElementById('Predict').innerHTML = (
'The Testoutfit is rated ' + IRIS_CLASSES[0] + '. (It is to ' + arraytensor[0] + 'sure)'
);
} else {
console.log(IRIS_CLASSES[1])
document.getElementById('Predict').innerHTML = (
'The Testoutfit is rated ' + IRIS_CLASSES[1] + ' . (It is to ' + arraytensor[1] + 'sure)'
);
}
//Find new good Outfit
var wert = 0
var min = 1;
function random (max) {
var x = Math.round((Math.random() * (max - min)) + min);
return x;
}
var rundenwert = 1;
while (wert!=1) {
//Create new random Outfit
var x1 = random(Kleidung[0].length-1);
var y1 = random(Kleidung[1].length-1);
var x2 = random(Kleidung[0].length-1);
var y2 = random(Kleidung[1].length-1);
var array = [];
var array2 = [];
var array_x1 = array.push(Kleidung[0][x1][0]);
var array_y1 = array.push(Kleidung[1][y1][0]);
var array_x2 = array.push(Kleidung[0][x2][0]);
var array_y2 = array.push(Kleidung[1][y2][0]);
var druck = array[0] + ', ' + array[1] + ', ' + array[2] + ', ' + array[3];
array.forEach(element => {
array2.push(parseFloat(element));
});
console.log('Runde ' + rundenwert);
document.getElementById("Array Outfit").innerHTML = 'Finales Outfit Array: ' + druck;
document.getElementById("1o").innerHTML = '1. Top -' + Kleidung[0][x1][1];
document.getElementById("1u").innerHTML = '1. Lower part -' + Kleidung[1][y1][1];
document.getElementById("2o").innerHTML = '2. Top -' + Kleidung[0][x2][1];
document.getElementById("2u").innerHTML = '2. Lower part -' + Kleidung[1][y2][1];
console.log(druck);
console.log(array2);
//Rate the generated Outfit
console.log(model.predict(tf.oneHot([array2], 27)));
document.getElementById('Predict Outfit').innerHTML = model.predict(tf.oneHot([array2], 27));
var predicttensor = TensortoArray('Predict Outfit');
if (predicttensor[0]>predicttensor[1]) {
console.log(IRIS_CLASSES[0])
document.getElementById('Predict Outfit').innerHTML = 'The final outfit is rated ' + IRIS_CLASSES[0] + '. (It is to ' + predicttensor[0] + 'sure)';
} else if (predicttensor[1]>60) {
console.log(IRIS_CLASSES[1])
document.getElementById('Predict Outfit').innerHTML = 'The final outfit is rated ' + IRIS_CLASSES[1] + ' bewertet. (It is to ' + predicttensor[1] + 'sure)';
wert = 1;
}
document.getElementById('Sicherheit Predict').innerHTML = '<progress id="progress" value="' + predicttensor[0] + '" max="100"></progress><label> Schlecht: ' + predicttensor[0] + '%</label><br><progress id="progress" value="' + predicttensor[1] + '" max="100"></progress><label> Gut: ' + predicttensor[1] + '%</label>';
rundenwert++;
document.getElementById('Rundenzahl').innerHTML = 'It was ' + rundenwert + ' Rounds used to find a good outfit.';
//If no Outfit is find -> stop
if (rundenwert>500) {
document.getElementById("Rundenzahl").innerHTML = 'That took to long. <br> No good Outfit was found.';
wert = 1;
}
}
//Predict Test2
console.log('test2 ' + model.predict(tf.oneHot([[1,4,3,10]], 27)));
console.log('test ' + model.predict(tf.oneHot([[3,4,8,13]], 27)));
//Model Save
await model.save('http:...')
return model;
}
Removing one of the outputs makes the problem much easier; as such, perhaps you should reduce your learning rate to something like 0.01 or 0.001 so it doesn't overshoot an easier solution.

THREE.JS + Delaunator.JS Keeping faces indexing

Probably this question is for Mapbox team and Delaunator.JS developers, but I hope that somebody could help me here.
I have a pseudo quadtree geometry (THREE.BufferGeometry) set by series of points having seven partitions with their individual draw call (geometry.addGroup() method) and material.
//pseudo quadtree
var points = [], indices = [], quad_uvs = [], groups = [], materials = [];
getSegmentSubpoints(0, new THREE.Vector3(-1024, 0, -1024), 1024, 1024, 4);
getSegmentSubpoints(1, new THREE.Vector3(0, 0, -1024), 1024, 1024, 4);
getSegmentSubpoints(2, new THREE.Vector3(-1024, 0, 0), 1024, 1024, 4);
getSegmentSubpoints(3, new THREE.Vector3(0, 0, 0), 512, 512, 8);
getSegmentSubpoints(4, new THREE.Vector3(512, 0, 0), 512, 512, 8);
getSegmentSubpoints(5, new THREE.Vector3(0, 0, 512), 512, 512, 8);
getSegmentSubpoints(6, new THREE.Vector3(512, 0, 512), 512, 512, 8);
var geometry = new THREE.BufferGeometry().setFromPoints(points);
geometry.setIndex(indices);
geometry.setAttribute( 'uv', new THREE.BufferAttribute(new Float32Array(quad_uvs), 2 ) );
geometry.computeVertexNormals();
var colors = [new THREE.Color(0xe6194b), new THREE.Color(0x3cb44b), new THREE.Color(0xffe119), new THREE.Color(0x4363d8), new THREE.Color(0xf58231), new THREE.Color(0x911eb4), new THREE.Color(0x46f0f0) ]
groups.forEach(function(g_, i_){ geometry.addGroup(g_.start, g_.end, g_.id); });
var plane = new THREE.Mesh(geometry, materials);
plane.rotation.set(Math.PI, 0, 0);
plane.position.set(-1152, 0, 0);
scene.add(plane);
function getSegmentSubpoints(id_, lt_, w_, h_, level_){
var subpoints = [];
var subindices = [];
var subquad = [];
var lastIndex = points.length;
var lastIndex2 = indices.length;
var step = {x: w_ / level_, z: h_ / level_ };
var stepT = {x: 1.0 / level_, z: 1.0 / level_ };
for(var z = 0; z <= level_; z++){
for(var x = 0; x <= level_; x++){
var dx = lt_.x + step.x * x;
var dz = lt_.z + step.z * z;
var dy = noise.simplex2(dx / 512.0, dz / 512.0) * 32.0;
subquad.push(...[stepT.x * x, stepT.z * z]);
subpoints.push(new THREE.Vector3(dx, dy, dz));
}
}
for(var i = 0; i < subpoints.length - level_ - 2; i++) {
if(i % (level_ + 1) != (level_)){
subindices.push(lastIndex + i, lastIndex + i + 1, lastIndex + i + level_ + 2, lastIndex + i + level_ + 2, lastIndex + i + level_ + 1, lastIndex + i);
}
}
points.push(...subpoints);
indices.push(...subindices);
quad_uvs.push(...subquad);
groups.push({id: id_, start: lastIndex2, end: subindices.length});
materials.push(new THREE.MeshBasicMaterial({ wireframe: true, map: new THREE.TextureLoader().load("textures/" + id_ + ".jpg")}));
}
Everything is fine, but for my project I have to process the current geometry through Delaunator.JS and it seems that the output has different triangles/faces indexing starting from the center.
There is dynamic colors for each segment to visualize indexing. Eventually, it has to be the same as previous one with seven materials and individual draw calls.
//delaunay
var geometry = new THREE.BufferGeometry().setFromPoints(points);
var indexDelaunay = Delaunator.from(points.map(v => { return [v.x, v.z]; }) );
var meshIndex = [];
for (let i = 0; i < indexDelaunay.triangles.length; i++){ meshIndex.push(indexDelaunay.triangles[i]); }
geometry.setIndex(meshIndex);
geometry.computeVertexNormals();
count = 0;
for(var i = 0; i < meshIndex.length; i += 6){
geometry.addGroup(i, 6, i / 6);
materials.push(new THREE.MeshBasicMaterial({ wireframe: true, color: new THREE.Color("hsl(" + (360 / 316 * count) + ",80%, 80%)")}))
count++;
}
var plane = new THREE.Mesh(geometry, materials);
plane.rotation.set(Math.PI, 0, 0)
plane.position.set(1152, 0, 0);
scene.add(plane);
So is there a way to re-index faces back so I could get the same result?
Yes, I could go through each Delaunator.triangles check its position/area for if it fits the certain partition, but it's not an elegant and fast solution. I bet it's possible to tweak Delaunator.JS code for right indexing on the fly.
The snippet is attached as well.
//https://hofk.de/main/discourse.threejs/2018/Triangulation/Triangulation.html
////by Mapbox https://github.com/mapbox/delaunator
(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
typeof define === 'function' && define.amd ? define(factory) :
(global.Delaunator = factory());
}(this, (function () { 'use strict';
var EPSILON = Math.pow(2, -52);
var Delaunator = function Delaunator(coords) {
var this$1 = this;
var n = coords.length >> 1;
if (n > 0 && typeof coords[0] !== 'number') { throw new Error('Expected coords to contain numbers.'); }
this.coords = coords;
var maxTriangles = 2 * n - 5;
var triangles = this.triangles = new Uint32Array(maxTriangles * 3);
var halfedges = this.halfedges = new Int32Array(maxTriangles * 3);
this._hashSize = Math.ceil(Math.sqrt(n));
var hullPrev = this.hullPrev = new Uint32Array(n);
var hullNext = this.hullNext = new Uint32Array(n);
var hullTri = this.hullTri = new Uint32Array(n);
var hullHash = new Int32Array(this._hashSize).fill(-1);
var ids = new Uint32Array(n);
var minX = Infinity;
var minY = Infinity;
var maxX = -Infinity;
var maxY = -Infinity;
for (var i = 0; i < n; i++) {
var x = coords[2 * i];
var y = coords[2 * i + 1];
if (x < minX) { minX = x; }
if (y < minY) { minY = y; }
if (x > maxX) { maxX = x; }
if (y > maxY) { maxY = y; }
ids[i] = i;
}
var cx = (minX + maxX) / 2;
var cy = (minY + maxY) / 2;
var minDist = Infinity;
var i0, i1, i2;
for (var i$1 = 0; i$1 < n; i$1++) {
var d = dist(cx, cy, coords[2 * i$1], coords[2 * i$1 + 1]);
if (d < minDist) {
i0 = i$1;
minDist = d;
}
}
var i0x = coords[2 * i0];
var i0y = coords[2 * i0 + 1];
minDist = Infinity;
for (var i$2 = 0; i$2 < n; i$2++) {
if (i$2 === i0) { continue; }
var d$1 = dist(i0x, i0y, coords[2 * i$2], coords[2 * i$2 + 1]);
if (d$1 < minDist && d$1 > 0) {
i1 = i$2;
minDist = d$1;
}
}
var i1x = coords[2 * i1];
var i1y = coords[2 * i1 + 1];
var minRadius = Infinity;
for (var i$3 = 0; i$3 < n; i$3++) {
if (i$3 === i0 || i$3 === i1) { continue; }
var r = circumradius(i0x, i0y, i1x, i1y, coords[2 * i$3], coords[2 * i$3 + 1]);
if (r < minRadius) {
i2 = i$3;
minRadius = r;
}
}
var i2x = coords[2 * i2];
var i2y = coords[2 * i2 + 1];
if (minRadius === Infinity) {
throw new Error('No Delaunay triangulation exists for this input.');
}
if (orient(i0x, i0y, i1x, i1y, i2x, i2y)) {
var i$4 = i1;
var x$1 = i1x;
var y$1 = i1y;
i1 = i2;
i1x = i2x;
i1y = i2y;
i2 = i$4;
i2x = x$1;
i2y = y$1;
}
var center = circumcenter(i0x, i0y, i1x, i1y, i2x, i2y);
this._cx = center.x;
this._cy = center.y;
var dists = new Float64Array(n);
for (var i$5 = 0; i$5 < n; i$5++) {
dists[i$5] = dist(coords[2 * i$5], coords[2 * i$5 + 1], center.x, center.y);
}
quicksort(ids, dists, 0, n - 1);
this.hullStart = i0;
var hullSize = 3;
hullNext[i0] = hullPrev[i2] = i1;
hullNext[i1] = hullPrev[i0] = i2;
hullNext[i2] = hullPrev[i1] = i0;
hullTri[i0] = 0;
hullTri[i1] = 1;
hullTri[i2] = 2;
hullHash[this._hashKey(i0x, i0y)] = i0;
hullHash[this._hashKey(i1x, i1y)] = i1;
hullHash[this._hashKey(i2x, i2y)] = i2;
this.trianglesLen = 0;
this._addTriangle(i0, i1, i2, -1, -1, -1);
for (var k = 0, xp = (void 0), yp = (void 0); k < ids.length; k++) {
var i$6 = ids[k];
var x$2 = coords[2 * i$6];
var y$2 = coords[2 * i$6 + 1];
if (k > 0 && Math.abs(x$2 - xp) <= EPSILON && Math.abs(y$2 - yp) <= EPSILON) { continue; }
xp = x$2;
yp = y$2;
if (i$6 === i0 || i$6 === i1 || i$6 === i2) { continue; }
var start = 0;
for (var j = 0, key = this._hashKey(x$2, y$2); j < this._hashSize; j++) {
start = hullHash[(key + j) % this$1._hashSize];
if (start !== -1 && start !== hullNext[start]) { break; }
}
start = hullPrev[start];
var e = start, q = (void 0);
while (q = hullNext[e], !orient(x$2, y$2, coords[2 * e], coords[2 * e + 1], coords[2 * q], coords[2 * q + 1])) {
e = q;
if (e === start) {
e = -1;
break;
}
}
if (e === -1) { continue; }
var t = this$1._addTriangle(e, i$6, hullNext[e], -1, -1, hullTri[e]);
hullTri[i$6] = this$1._legalize(t + 2);
hullTri[e] = t;
hullSize++;
var n$1 = hullNext[e];
while (q = hullNext[n$1], orient(x$2, y$2, coords[2 * n$1], coords[2 * n$1 + 1], coords[2 * q], coords[2 * q + 1])) {
t = this$1._addTriangle(n$1, i$6, q, hullTri[i$6], -1, hullTri[n$1]);
hullTri[i$6] = this$1._legalize(t + 2);
hullNext[n$1] = n$1;
hullSize--;
n$1 = q;
}
if (e === start) {
while (q = hullPrev[e], orient(x$2, y$2, coords[2 * q], coords[2 * q + 1], coords[2 * e], coords[2 * e + 1])) {
t = this$1._addTriangle(q, i$6, e, -1, hullTri[e], hullTri[q]);
this$1._legalize(t + 2);
hullTri[q] = t;
hullNext[e] = e;
hullSize--;
e = q;
}
}
this$1.hullStart = hullPrev[i$6] = e;
hullNext[e] = hullPrev[n$1] = i$6;
hullNext[i$6] = n$1;
hullHash[this$1._hashKey(x$2, y$2)] = i$6;
hullHash[this$1._hashKey(coords[2 * e], coords[2 * e + 1])] = e;
}
this.hull = new Uint32Array(hullSize);
for (var i$7 = 0, e$1 = this.hullStart; i$7 < hullSize; i$7++) {
this$1.hull[i$7] = e$1;
e$1 = hullNext[e$1];
}
this.hullPrev = this.hullNext = this.hullTri = null;
this.triangles = triangles.subarray(0, this.trianglesLen);
this.halfedges = halfedges.subarray(0, this.trianglesLen);
};
Delaunator.from = function from (points, getX, getY) {
if ( getX === void 0 ) getX = defaultGetX;
if ( getY === void 0 ) getY = defaultGetY;
var n = points.length;
var coords = new Float64Array(n * 2);
for (var i = 0; i < n; i++) {
var p = points[i];
coords[2 * i] = getX(p);
coords[2 * i + 1] = getY(p);
}
return new Delaunator(coords);
};
Delaunator.prototype._hashKey = function _hashKey (x, y) {
return Math.floor(pseudoAngle(x - this._cx, y - this._cy) * this._hashSize) % this._hashSize;
};
Delaunator.prototype._legalize = function _legalize (a) {
var this$1 = this;
var ref = this;
var triangles = ref.triangles;
var coords = ref.coords;
var halfedges = ref.halfedges;
var b = halfedges[a];
var a0 = a - a % 3;
var b0 = b - b % 3;
var al = a0 + (a + 1) % 3;
var ar = a0 + (a + 2) % 3;
var bl = b0 + (b + 2) % 3;
if (b === -1) { return ar; }
var p0 = triangles[ar];
var pr = triangles[a];
var pl = triangles[al];
var p1 = triangles[bl];
var illegal = inCircle(
coords[2 * p0], coords[2 * p0 + 1],
coords[2 * pr], coords[2 * pr + 1],
coords[2 * pl], coords[2 * pl + 1],
coords[2 * p1], coords[2 * p1 + 1]);
if (illegal) {
triangles[a] = p1;
triangles[b] = p0;
var hbl = halfedges[bl];
if (hbl === -1) {
var e = this.hullStart;
do {
if (this$1.hullTri[e] === bl) {
this$1.hullTri[e] = a;
break;
}
e = this$1.hullNext[e];
} while (e !== this.hullStart);
}
this._link(a, hbl);
this._link(b, halfedges[ar]);
this._link(ar, bl);
var br = b0 + (b + 1) % 3;
this._legalize(a);
return this._legalize(br);
}
return ar;
};
Delaunator.prototype._link = function _link (a, b) {
this.halfedges[a] = b;
if (b !== -1) { this.halfedges[b] = a; }
};
Delaunator.prototype._addTriangle = function _addTriangle (i0, i1, i2, a, b, c) {
var t = this.trianglesLen;
this.triangles[t] = i0;
this.triangles[t + 1] = i1;
this.triangles[t + 2] = i2;
this._link(t, a);
this._link(t + 1, b);
this._link(t + 2, c);
this.trianglesLen += 3;
return t;
};
function pseudoAngle(dx, dy) {
var p = dx / (Math.abs(dx) + Math.abs(dy));
return (dy > 0 ? 3 - p : 1 + p) / 4;
}
function dist(ax, ay, bx, by) {
var dx = ax - bx;
var dy = ay - by;
return dx * dx + dy * dy;
}
function orient(px, py, qx, qy, rx, ry) {
return (qy - py) * (rx - qx) - (qx - px) * (ry - qy) < 0;
}
function inCircle(ax, ay, bx, by, cx, cy, px, py) {
var dx = ax - px;
var dy = ay - py;
var ex = bx - px;
var ey = by - py;
var fx = cx - px;
var fy = cy - py;
var ap = dx * dx + dy * dy;
var bp = ex * ex + ey * ey;
var cp = fx * fx + fy * fy;
return dx * (ey * cp - bp * fy) -
dy * (ex * cp - bp * fx) +
ap * (ex * fy - ey * fx) < 0;
}
function circumradius(ax, ay, bx, by, cx, cy) {
var dx = bx - ax;
var dy = by - ay;
var ex = cx - ax;
var ey = cy - ay;
var bl = dx * dx + dy * dy;
var cl = ex * ex + ey * ey;
var d = 0.5 / (dx * ey - dy * ex);
var x = (ey * bl - dy * cl) * d;
var y = (dx * cl - ex * bl) * d;
return x * x + y * y;
}
function circumcenter(ax, ay, bx, by, cx, cy) {
var dx = bx - ax;
var dy = by - ay;
var ex = cx - ax;
var ey = cy - ay;
var bl = dx * dx + dy * dy;
var cl = ex * ex + ey * ey;
var d = 0.5 / (dx * ey - dy * ex);
var x = ax + (ey * bl - dy * cl) * d;
var y = ay + (dx * cl - ex * bl) * d;
return {x: x, y: y};
}
function quicksort(ids, dists, left, right) {
if (right - left <= 20) {
for (var i = left + 1; i <= right; i++) {
var temp = ids[i];
var tempDist = dists[temp];
var j = i - 1;
while (j >= left && dists[ids[j]] > tempDist) { ids[j + 1] = ids[j--]; }
ids[j + 1] = temp;
}
} else {
var median = (left + right) >> 1;
var i$1 = left + 1;
var j$1 = right;
swap(ids, median, i$1);
if (dists[ids[left]] > dists[ids[right]]) { swap(ids, left, right); }
if (dists[ids[i$1]] > dists[ids[right]]) { swap(ids, i$1, right); }
if (dists[ids[left]] > dists[ids[i$1]]) { swap(ids, left, i$1); }
var temp$1 = ids[i$1];
var tempDist$1 = dists[temp$1];
while (true) {
do { i$1++; } while (dists[ids[i$1]] < tempDist$1);
do { j$1--; } while (dists[ids[j$1]] > tempDist$1);
if (j$1 < i$1) { break; }
swap(ids, i$1, j$1);
}
ids[left + 1] = ids[j$1];
ids[j$1] = temp$1;
if (right - i$1 + 1 >= j$1 - left) {
quicksort(ids, dists, i$1, right);
quicksort(ids, dists, left, j$1 - 1);
} else {
quicksort(ids, dists, left, j$1 - 1);
quicksort(ids, dists, i$1, right);
}
}
}
function swap(arr, i, j) {
var tmp = arr[i];
arr[i] = arr[j];
arr[j] = tmp;
}
function defaultGetX(p) {
return p[0];
}
function defaultGetY(p) {
return p[1];
}
return Delaunator;
})));
var renderer, scene, camera, controls, loader, terrain, glsl, uniforms, root, tree;
renderer = new THREE.WebGLRenderer({
antialias: true
});
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setClearColor(0x000000);
document.body.appendChild(renderer.domElement);
scene = new THREE.Scene();
loader = new THREE.TextureLoader();
loader.crossOrigin = "";
camera = new THREE.PerspectiveCamera(35, window.innerWidth / window.innerHeight, 1, 51200);
camera.position.set(-3072, 2048, -3072);
controls = new THREE.OrbitControls(camera, renderer.domElement);
controls.enableDamping = true;
controls.dampingFactor = 0.05;
controls.screenSpacePanning = false;
controls.minDistance = 8;
controls.maxDistance = 10240;
controls.maxPolarAngle = Math.PI / 2;
//simple pseudo quadtree
var points = [], indices = [], quad_uvs = [], groups = [], materials = [];
getSegmentSubpoints(0, new THREE.Vector3(-1024, 0, -1024), 1024, 1024, 4);
getSegmentSubpoints(1, new THREE.Vector3(0, 0, -1024), 1024, 1024, 4);
getSegmentSubpoints(2, new THREE.Vector3(-1024, 0, 0), 1024, 1024, 4);
getSegmentSubpoints(3, new THREE.Vector3(0, 0, 0), 512, 512, 8);
getSegmentSubpoints(4, new THREE.Vector3(512, 0, 0), 512, 512, 8);
getSegmentSubpoints(5, new THREE.Vector3(0, 0, 512), 512, 512, 8);
getSegmentSubpoints(6, new THREE.Vector3(512, 0, 512), 512, 512, 8);
var geometry = new THREE.BufferGeometry().setFromPoints(points);
geometry.setIndex(indices);
geometry.setAttribute( 'uv', new THREE.BufferAttribute(new Float32Array(quad_uvs), 2 ) );
geometry.computeVertexNormals();
var materials = [];
var colors = [new THREE.Color(0xe6194b), new THREE.Color(0x3cb44b), new THREE.Color(0xffe119), new THREE.Color(0x4363d8), new THREE.Color(0xf58231), new THREE.Color(0x911eb4), new THREE.Color(0x46f0f0) ]
groups.forEach(function(g_, i_){ geometry.addGroup(g_.start, g_.end, g_.id); materials.push(new THREE.MeshBasicMaterial({wireframe: true, color: colors[i_]})) });
var plane = new THREE.Mesh(geometry, materials);
plane.rotation.set(Math.PI, 0, 0);
plane.position.set(-1152, 0, 0);
scene.add(plane);
//delaunay
materials = [];
var geometry = new THREE.BufferGeometry().setFromPoints(points);
var indexDelaunay = Delaunator.from(points.map(v => { return [v.x, v.z]; }) );
var meshIndex = [];
for (let i = 0; i < indexDelaunay.triangles.length; i++){ meshIndex.push(indexDelaunay.triangles[i]); }
geometry.setIndex(meshIndex);
geometry.computeVertexNormals();
count = 0;
for(var i = 0; i < meshIndex.length; i += 6){
geometry.addGroup(i, 6, i / 6);
materials.push(new THREE.MeshBasicMaterial({ wireframe: true, color: new THREE.Color("hsl(" + (360 / 316 * count) + ",80%, 80%)")}))
count++;
}
var plane = new THREE.Mesh(geometry, materials); //new THREE.MeshBasicMaterial({color: 0xFF00FF, side: THREE.DoubleSide, wireframe: true}) );
plane.rotation.set(Math.PI, 0, 0)
plane.position.set(1152, 0, 0);
scene.add(plane);
animate();
function getSegmentSubpoints(id_, lt_, w_, h_, level_){
var subpoints = [];
var subindices = [];
var subquad = [];
var lastIndex = points.length;
var lastIndex2 = indices.length;
var step = {x: w_ / level_, z: h_ / level_ };
var stepT = {x: 1.0 / level_, z: 1.0 / level_ };
for(var z = 0; z <= level_; z++){
for(var x = 0; x <= level_; x++){
var dx = lt_.x + step.x * x;
var dz = lt_.z + step.z * z;
var dy = 0;
subquad.push(...[stepT.x * x, stepT.z * z]);
subpoints.push(new THREE.Vector3(dx, dy, dz));
}
}
for(var i = 0; i < subpoints.length - level_ - 2; i++) {
if(i % (level_ + 1) != (level_)){
subindices.push(lastIndex + i, lastIndex + i + 1, lastIndex + i + level_ + 2, lastIndex + i + level_ + 2, lastIndex + i + level_ + 1, lastIndex + i);
}
}
points.push(...subpoints);
indices.push(...subindices);
quad_uvs.push(...subquad);
groups.push({id: id_, start: lastIndex2, end: subindices.length});
materials.push(new THREE.MeshBasicMaterial({ wireframe: true, map: new THREE.TextureLoader().load("textures/" + id_ + ".jpg")}));
}
function animate(){
controls.update();
renderer.render(scene, camera);
requestAnimationFrame(animate);
}
body { margin: 0; }
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>GLSL Intersection</title>
<meta name="viewport" content="initial-scale=1,maximum-scale=1,user-scalable=no" />
<script src="https://unpkg.com/three#0.116.0/build/three.min.js"></script>
<script src="https://unpkg.com/three#0.116.0/examples/js/controls/OrbitControls.js"></script>
</head>
<body>
</body>
</html>

How calulate the area of a polygon in react-native-maps?

I am passing the array of co-ordinates to the polygon and want to find the area of the polygon through that co-ordinates. I have checked the documentation of the react-native-maps but there is no function provided.
Is there is any way to calculate the area.
Thanks in advance.
Library will not give you this functionality.
Try this
function calcArea(locations) {
if (!locations.length) {
return 0;
}
if (locations.length < 3) {
return 0;
}
let radius = 6371000;
const diameter = radius * 2;
const circumference = diameter * Math.PI;
const listY = [];
const listX = [];
const listArea = [];
// calculate segment x and y in degrees for each point
const latitudeRef = locations[0].latitude;
const longitudeRef = locations[0].longitude;
for (let i = 1; i < locations.length; i++) {
let latitude = locations[i].latitude;
let longitude = locations[i].longitude;
listY.push(this.calculateYSegment(latitudeRef, latitude, circumference));
listX.push(this.calculateXSegment(longitudeRef, longitude, latitude, circumference));
}
// calculate areas for each triangle segment
for (let i = 1; i < listX.length; i++) {
let x1 = listX[i - 1];
let y1 = listY[i - 1];
let x2 = listX[i];
let y2 = listY[i];
listArea.push(this.calculateAreaInSquareMeters(x1, x2, y1, y2));
}
// sum areas of all triangle segments
let areasSum = 0;
listArea.forEach(area => areasSum = areasSum + area)
// get abolute value of area, it can't be negative
let areaCalc = Math.abs(areasSum);// Math.sqrt(areasSum * areasSum);
return areaCalc;
}
function calculateAreaInSquareMeters(x1, x2, y1, y2) {
return (y1 * x2 - x1 * y2) / 2;
}
function calculateYSegment(latitudeRef, latitude, circumference) {
return (latitude - latitudeRef) * circumference / 360.0;
}
function calculateXSegment(longitudeRef, longitude, latitude, circumference) {
return (longitude - longitudeRef) * circumference * Math.cos((latitude * (Math.PI / 180))) / 360.0;
}
Reference

Calculate vertical bearing between two GPS coordinates with altitudes

I am planning to build an antenna tracker. I need to get bearing and tilt from GPS point A with altitude and GPS point B with altitude.
This is the example points:
latA = 39.099912
lonA = -94.581213
altA = 273.543
latB = 38.627089
lonB = -90.200203
altB = 1380.245
I've already got the formula for horizontal bearing and it gives me 97.89138167122422
This is the code:
function toRadian(num) {
return num * (Math.PI / 180);
}
function toDegree(num) {
return num * (180 / Math.PI);
}
function getHorizontalBearing(fromLat, fromLon, toLat, toLon) {
fromLat = toRadian(fromLat);
fromLon = toRadian(fromLon);
toLat = toRadian(toLat);
toLon = toRadian(toLon);
let dLon = toLon - fromLon;
let x = Math.tan(toLat / 2 + Math.PI / 4);
let y = Math.tan(fromLat / 2 + Math.PI / 4);
let dPhi = Math.log(x / y);
if (Math.abs(dLon) > Math.PI) {
if (dLon > 0.0) {
dLon = -(2 * Math.PI - dLon);
} else {
dLon = (2 * Math.PI + dLon);
}
}
return (toDegree(Math.atan2(dLon, dPhi)) + 360) % 360;
}
let n = getHorizontalBearing(39.099912, -94.581213, 38.627089, -90.200203);
console.info(n);
But I don't know how to find the tilt angle. Anyone could help me?
I think I got the answer after searching around.
This is the complete code, if you think this is wrong, feel free to correct me.
function toRadian(num) {
return num * (Math.PI / 180);
}
function toDegree(num) {
return num * (180 / Math.PI);
}
// North is 0 degree, South is 180 degree
function getHorizontalBearing(fromLat, fromLon, toLat, toLon, currentBearing) {
fromLat = toRadian(fromLat);
fromLon = toRadian(fromLon);
toLat = toRadian(toLat);
toLon = toRadian(toLon);
let dLon = toLon - fromLon;
let x = Math.tan(toLat / 2 + Math.PI / 4);
let y = Math.tan(fromLat / 2 + Math.PI / 4);
let dPhi = Math.log(x / y);
if (Math.abs(dLon) > Math.PI) {
if (dLon > 0.0) {
dLon = -(2 * Math.PI - dLon);
} else {
dLon = (2 * Math.PI + dLon);
}
}
let targetBearing = (toDegree(Math.atan2(dLon, dPhi)) + 360) % 360;
return targetBearing - currentBearing;
}
// Horizon is 0 degree, Up is 90 degree
function getVerticalBearing(fromLat, fromLon, fromAlt, toLat, toLon, toAlt, currentElevation) {
fromLat = toRadian(fromLat);
fromLon = toRadian(fromLon);
toLat = toRadian(toLat);
toLon = toRadian(toLon);
let fromECEF = getECEF(fromLat, fromLon, fromAlt);
let toECEF = getECEF(toLat, toLon, toAlt);
let deltaECEF = getDeltaECEF(fromECEF, toECEF);
let d = (fromECEF[0] * deltaECEF[0] + fromECEF[1] * deltaECEF[1] + fromECEF[2] * deltaECEF[2]);
let a = ((fromECEF[0] * fromECEF[0]) + (fromECEF[1] * fromECEF[1]) + (fromECEF[2] * fromECEF[2]));
let b = ((deltaECEF[0] * deltaECEF[0]) + (deltaECEF[2] * deltaECEF[2]) + (deltaECEF[2] * deltaECEF[2]));
let elevation = toDegree(Math.acos(d / Math.sqrt(a * b)));
elevation = 90 - elevation;
return elevation - currentElevation;
}
function getDeltaECEF(from, to) {
let X = to[0] - from[0];
let Y = to[1] - from[1];
let Z = to[2] - from[2];
return [X, Y, Z];
}
function getECEF(lat, lon, alt) {
let radius = 6378137;
let flatteningDenom = 298.257223563;
let flattening = 0.003352811;
let polarRadius = 6356752.312106893;
let asqr = radius * radius;
let bsqr = polarRadius * polarRadius;
let e = Math.sqrt((asqr-bsqr)/asqr);
// let eprime = Math.sqrt((asqr-bsqr)/bsqr);
let N = getN(radius, e, lat);
let ratio = (bsqr / asqr);
let X = (N + alt) * Math.cos(lat) * Math.cos(lon);
let Y = (N + alt) * Math.cos(lat) * Math.sin(lon);
let Z = (ratio * N + alt) * Math.sin(lat);
return [X, Y, Z];
}
function getN(a, e, latitude) {
let sinlatitude = Math.sin(latitude);
let denom = Math.sqrt(1 - e * e * sinlatitude * sinlatitude);
return a / denom;
}
let n = getHorizontalBearing(39.099912, -94.581213, 39.099912, -94.588032, 0.00);
console.info("Horizontal bearing:\t", n);
let m = getVerticalBearing(39.099912, -94.581213, 273.543, 39.099912, -94.588032, 873.543, 0.0);
console.info("Vertical bearing:\t", m);
Don Cross's javascript code produces good results. It takes into consideration the curvature of the earth plus the fact that the earth is oblate.
Example:
var elDegrees = calculateElevationAngleCosineKitty(
{latitude: 35.346257, longitude: -97.863801, altitudeMetres: 10},
{latitude: 34.450545, longitude: -96.500167, altitudeMetres: 9873}
);
console.log("El: " + elDegrees);
/***********************************
Code by Don Cross at cosinekitty.com
http://cosinekitty.com/compass.html
************************************/
function calculateElevationAngleCosineKitty(source, target)
{
var oblate = true;
var a = {'lat':source.latitude, 'lon':source.longitude, 'elv':source.altitudeMetres};
var b = {'lat':target.latitude, 'lon':target.longitude, 'elv':target.altitudeMetres};
var ap = LocationToPoint(a, oblate);
var bp = LocationToPoint(b, oblate);
var bma = NormalizeVectorDiff(bp, ap);
var elevation = 90.0 - (180.0 / Math.PI)*Math.acos(bma.x*ap.nx + bma.y*ap.ny + bma.z*ap.nz);
return elevation;
}
function NormalizeVectorDiff(b, a)
{
// Calculate norm(b-a), where norm divides a vector by its length to produce a unit vector.
var dx = b.x - a.x;
var dy = b.y - a.y;
var dz = b.z - a.z;
var dist2 = dx*dx + dy*dy + dz*dz;
if (dist2 == 0) {
return null;
}
var dist = Math.sqrt(dist2);
return { 'x':(dx/dist), 'y':(dy/dist), 'z':(dz/dist), 'radius':1.0 };
}
function EarthRadiusInMeters (latitudeRadians) // latitude is geodetic, i.e. that reported by GPS
{
// http://en.wikipedia.org/wiki/Earth_radius
var a = 6378137.0; // equatorial radius in meters
var b = 6356752.3; // polar radius in meters
var cos = Math.cos (latitudeRadians);
var sin = Math.sin (latitudeRadians);
var t1 = a * a * cos;
var t2 = b * b * sin;
var t3 = a * cos;
var t4 = b * sin;
return Math.sqrt ((t1*t1 + t2*t2) / (t3*t3 + t4*t4));
}
function GeocentricLatitude(lat)
{
// Convert geodetic latitude 'lat' to a geocentric latitude 'clat'.
// Geodetic latitude is the latitude as given by GPS.
// Geocentric latitude is the angle measured from center of Earth between a point and the equator.
// https://en.wikipedia.org/wiki/Latitude#Geocentric_latitude
var e2 = 0.00669437999014;
var clat = Math.atan((1.0 - e2) * Math.tan(lat));
return clat;
}
function LocationToPoint(c, oblate)
{
// Convert (lat, lon, elv) to (x, y, z).
var lat = c.lat * Math.PI / 180.0;
var lon = c.lon * Math.PI / 180.0;
var radius = oblate ? EarthRadiusInMeters(lat) : 6371009;
var clat = oblate ? GeocentricLatitude(lat) : lat;
var cosLon = Math.cos(lon);
var sinLon = Math.sin(lon);
var cosLat = Math.cos(clat);
var sinLat = Math.sin(clat);
var x = radius * cosLon * cosLat;
var y = radius * sinLon * cosLat;
var z = radius * sinLat;
// We used geocentric latitude to calculate (x,y,z) on the Earth's ellipsoid.
// Now we use geodetic latitude to calculate normal vector from the surface, to correct for elevation.
var cosGlat = Math.cos(lat);
var sinGlat = Math.sin(lat);
var nx = cosGlat * cosLon;
var ny = cosGlat * sinLon;
var nz = sinGlat;
x += c.elv * nx;
y += c.elv * ny;
z += c.elv * nz;
return {'x':x, 'y':y, 'z':z, 'radius':radius, 'nx':nx, 'ny':ny, 'nz':nz};
}
/***********************
END cosinekitty.com code
************************/