//// naive O(n^2) algorithm for verifying fft algorithm
  my.Complex2.prototype.dft = function(mode) {
    var ee, ii2, ll2, tmp;
    ll2 = this[0].ll2; ee = my.Complex2(1, ll2); tmp = ee.copy();
    ee[1].set(my.Array2.range(ll2)).mul(-2 * Math.PI / ll2); if(mode === 'reverse') {ee.neg();}
    if(mode === 'reverse') {this.mul(1 / ll2);}
    this.each1(
      function(slice) {
        tmp.set([0, 0]);
        for(ii2 = 0; ii2 < ll2; ii2 += 1) {
          tmp.slice(null, null, ii2, ii2 + 1).dot2(
            ee.copy().mul(ii2).exp2(),
            slice
          );
        }
        slice.set(tmp);
      }
    );
  };