code: public void printCoordinate(int[] index, float[] dataR, float[] dataI,
              int offset) {
          int size = index.length;
          if (size != dataR.length || size != dataI.length)
              throw new IllegalArgumentException(
                      "All arrays must be of the same size");
          for (int i = 0; i < size; ++i)
              format(Locale.ENGLISH, "%10d % .12e % .12e%n", index[i] + offset,
                      dataR[i], dataI[i]);
      }
docs: Prints the coordinate format to the underlying stream. One index and
  entry on each line. The offset is added to each index, typically, this
  can transform from a 0-based indicing to a 1-based. The first float array
  specifies the real entries, and the second is the imaginary entries