code: function () {
  			// generate random solution to t-SNE
  			this.Y = randn2d(this.N, this.dim); // the solution
  			this.gains = randn2d(this.N, this.dim, 1.0); // step gains to accelerate progress in unchanging directions
  			this.ystep = randn2d(this.N, this.dim, 0.0); // momentum accumulator
  			this.iter = 0;
  		}
docs: (re)initializes the solution to random