Suggestion to add Bézier curves to Jason Snell’s weather station Scriptable widget.

Bezier.js

// Variables used by Scriptable.
// These must be at the very top of the file. Do not edit.
// icon-color: deep-purple; icon-glyph: chart-line;
const data = [59, 56, 52, 58, 57, 57, 52, 53]

// [points] to img of smooth (bezier) line graph
function lineGraph(points, width, height, line) {
  let context = new DrawContext()
  context.size = new Size(width, height)

  let max = Math.max(...points)
  let min = Math.min(...points)
  // calculate scale factors
  let fx = width / (points.length - 1)
  let fy = (height - line) / (max - min)

  // scale points, allowing for line width
  function scalePoint([x, y]) {
    let sx = x * fx
    let sy = (height - 2 * line) - (y - min) * fy
    return new Point(sx, sy)
  }
  
  // calculate bezier control points
  function controlPoint(current, previous, next, reverse) {
    const smoothing = 0.2
    const p = previous || current
    const n = next || current
    const dx = n[0] - p[0]
    const dy = n[1] - p[1]
    const angle = Math.atan2(dy, dx) + (reverse ? Math.PI : 0)
    const length = Math.sqrt(Math.pow(dy, 2) + Math.pow(dy, 2)) * smoothing
    const x = current[0] + Math.cos(angle) * length
    const y = current[1] + Math.sin(angle) * length
    return [x, y]
  }

  // create smooth path from points
  let path = new Path()
  points.map((p, i) => [i, p]).forEach((p, i, a) => {
    if (i === 0) {
      path.move(scalePoint(p))
    } else {
      let cps = controlPoint(a[i - 1], a[i - 2], p)
      let cpe = controlPoint(p, a[i - 1], a[i + 1], true)
      path.addCurve(scalePoint(p), scalePoint(cps), scalePoint(cpe))
    }
  })
  context.addPath(path)
  context.setLineWidth(line)
  context.setStrokeColor(Color.black())
  context.strokePath()
  return context.getImage()
}

let widget = new ListWidget()
let image = lineGraph(data, 500, 50, 2)
widget.addImage(image)
widget.presentMedium()
Script.complete()