code: public void elemApply(Lambda.FnIntDoubleToDouble fn) {
          for (int c=0; c<this.size; c++) {
              this.setValue(c, fn.call(c, this.getValue(c)));
          }
      }
docs: Adds a factor elementwise to this one.
  @param other The addend.
  @throws IllegalArgumentException If the two tensors have different sizes.