cdm/src/main/java/ucar/nc2/dataset/CoordinateAxis2D.java
public double getCoordValue(int j, int i) {
    if (coords == null) doRead();
    return coords.get(j, i);
  }
public double getCoordValue(int j, int i) {
    if (coords == null) doRead();
    return coords.get(j, i);
  }
Get the coordinate value at the i, j index.

@param i index 0 (fastest varying, right-most)
@param j index 1
@return midpoint.get(j, i).