angleDifference = (a, b) => {
const dot = a.x * a.x + b.y * b.y;
const cross = a.x * b.y - a.y * b.x;
return Math.atan2(cross, dot) / (2 * Math.PI);
}
csv = FileAttachment("sine_cos_encoder_test_4236rows.csv").csv({typed: true})
sum = (arr) => arr.reduce((sum, v) => sum + v, 0);
average = (arr) => sum(arr) / arr.length
max = (arr) => arr.reduce((max, v) => v > max ? v : max, -Infinity)
min = (arr) => arr.reduce((min, v) => v < min ? v : min, Infinity)
middle = (arr) => (max(arr) + min(arr)) / 2
height = (arr) => max(arr) - min(arr)
center = (arr) => {
const mid = middle(arr);
const scale = 2 / height(arr);
return arr.map((v) => (v - mid) * scale);
}
zipXY = (left, right) => {
const len = Math.min(left.length, right.length);
const out = Array(len);
for (let i = 0; i < out.length; i++) {
out[i] = {x: left[i], y: right[i]};
}
return out;
}
angularVelocity = (xy) => {
const arr = Array(xy.length - 1);
for (let i = 0; i < arr.length; i++) {
arr[i] = angleDifference(xy[i], xy[i+1]);
}
return arr;
}
integrate = (arr) => {
const out = Array(arr.length);
let sum = 0;
for (let i = 0; i < out.length; i++) {
sum += arr[i];
out[i] = sum;
}
return out;
}
digitize = (arr) => {
const out = new Array(arr.length);
out[0] = arr[0] > 0 ? 1 : 0;
for (let i = 1; i < out.length; i++) {
const threshold = out[i-1] == 1 ? -0.1 : 0.1
out[i] = (arr[i] > threshold) ? 1 : 0;
}
return out;
}
centerXY = (xy) => {
const xs = center(xy.map(({x, y}) => x));
const ys = center(xy.map(({x, y}) => y));
return zipXY(xs, ys);
}
normalizeRadius = (xy) => xy.map(({x, y}) => {
const r = Math.sqrt(x*x + y*y);
return {x: x/r, y: y/r};
});
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
