code: function(elevation){
  				if(this.__elevationLength == elevation.length){
  					for(var i = 0, len = elevation.length; i<len; i++){
  						this.vertices[i].y = this.elevation[i] = elevation[i];
  					}
  				} else {
  					throw new Error("the given elevation array size does not match terrain");
  				}
  				return this;
  			}
docs: Sets the elevation of all cells to those of the given array values.
  @param {Array} elevation array of height values
  @return itself