text: // export function phi(table){
  //   return (table[3] * table[0] - table[2] * table[1])/
  //   Math.sqrt((table[2] + table[3]) *
  //   (table[0] + table[1]) *
  //   (table[1] + table[3]) *
  //   (table[0] + table[2]));
  // };
  
  // note  the square brackets below for destructuring array
  export function phi([n00, n01, n10, n11]) {
    return (n11 * n00 - n10 * n01) /
      Math.sqrt((n10 + n11) * (n00 + n01) *
                (n01 + n11) * (n00 + n10));
  };