track.speed_min is always 0

[hupe13]

Hi Raruto,

I have found that the minimum speed is always 0. The cause seems to be here:

leaflet-elevation/src/handlers/speed.js

Lines 18 to 22 in 3ee745d

	pointToAttr: (_, i) => {
	let dx = (this._data[i].dist - this._data[i > 0 ? i - 1 : i].dist) * 1000;
	let dt = this._data[i].time - this._data[ i > 0 ? i - 1 : i].time;
	return dt > 0 ? Math.abs((dx / dt) * opts.timeFactor) * opts.speedFactor : 0;
	},

See your example.

I tried different things, but I can't solve the problem. Can you help me please?

Thank you very much.

[hupe13]

Maybe I found a solution. Change

leaflet-elevation/src/utils.js

Lines 135 to 136 in 3ee745d

	export const iMin = (iVal, min = +Infinity) => (iVal < min ? iVal : min);
	export const iAvg = (iVal, avg = 0, idx = 1) => (iVal + avg * (idx - 1)) / idx;

to

export const iMin = (iVal, min = +Infinity, idx = 1) => (idx > 1) ? (iVal < min ? iVal : min) : min;
export const iAvg = (iVal, avg = 0, idx = 1) => (iVal && idx > 1) ? (( iVal + avg * (idx - 1))) / idx : avg * (idx - 1) / idx;

I will made a pull request, when I'm ready.

[Raruto]

Hi hupe,
could you explain in detail the reason for this bug? (I don't have much time to understand this code..)

Even better, if you can write some tests that show the correctness of what you say:

leaflet-elevation/package.json

Line 10 in 3ee745d

"test": "node spec/index.js",

leaflet-elevation/spec/utils.test.js

Lines 9 to 23 in 3ee745d

	test('iAvg()', () => {
	let avg;
	avg = iAvg(100, undefined, 1); assert.is(toFixed(avg), 100); // average for [100] is 100
	avg = iAvg(100, avg, 2); assert.is(toFixed(avg), 100); // average for [100, 100] is 100
	avg = iAvg(200, avg, 3); assert.is(toFixed(avg), 133.33); // average for [100, 100, 200] is 133.33
	avg = iAvg(200, avg, 4); assert.is(toFixed(avg), 150); // average for [100, 100, 200, 200] is 150
	});
	test('iMin()', () => {
	let min;
	min = iMin(100, undefined); assert.is(toFixed(min), 100); // min for [100] is 100
	min = iMin(0, min); assert.is(toFixed(min), 0); // min for [100, 0] is 100
	min = iMin(-200, min); assert.is(toFixed(min), -200); // min for [100, 0, -200] is -200
	min = iMin(200, min); assert.is(toFixed(min), -200); // min for [100, -100, -200, 200] is -200
	});

[hupe13]

You can see this in your example for the 2016 Santa Rosa Marathon. When you run you don't pause, you always move. But the minimum speed is 0. I have to recap my tests, please be patient.
(It may be that the runner took a break during the marathon, but I have another gpx file for a run, there was definitely no break.)

[Raruto]

When you run you don't pause, you always move. But the minimum speed is 0. I have to recap my tests, please be patient.

You should check the instant t = 0 -> speed = dx / dt = 0

[Raruto]

Patch released in version 2.2.8