d3.csv.format = function(rows) {

  return rows.map(d3_csv_formatRow).join("\n");

};

function d3_csv_formatRow(row) {

  return row.map(d3_csv_formatValue).join(",");

}

function d3_csv_formatValue(text) {

  return /[",\n]/.test(text)

      ? "\"" + text.replace(/\"/g, "\"\"") + "\""

      : text;

}