calc = () => {
const output = doc.querySelector("output")
const vs = Array.from(doc.querySelectorAll(".cell > input")).map(i => parseInt(i.value))
const sum = vs.reduce((x, y) => x+y, 0)
const avg = sum / vs.length
const dev = Math.sqrt(vs.map(v => (v-avg)**2) .reduce((x, y) => x+y, 0)/vs.length)
switch (doc.querySelector("select").value) {
case "sum" : output.value = sum; break
case "avg" : output.value = avg; break
case "dev" : output.value = dev; break
}
}