[GAS]特定のセルから数値を拾い上げ中央値（メディアン）を取る関数

getMedian.gs

function getMedianByMonth(tagetYear, targetMonth) {
  const currentSS = SpreadsheetApp.getActiveSpreadsheet();
  const targetSheet = currentSS.getSheetByName(tagetYear);
  const targetRange = targetSheet.getDataRange();
  const tagetValues = targetRange.getValues();
  const result = tagetValues.filter(el => el[2] == targetMonth).map(x => x[9]);
  const median = (ary) => {
    if (ary.length === 0) {
      return 0;
    }
    ary.sort((a,b) => {
      return a - b;
    });
    const half = Math.floor(ary.length / 2);
    if (ary.length % 2) {
      return ary[half];
    } else {
      return (ary[half - 1] + ary[half]) / 2;
    }
  }
  return median(result);
}