cdm/src/main/java/ucar/nc2/ft/point/standard/CoordSysEvaluator.java
static public Dimension findDimensionByType(NetcdfDataset ds, AxisType atype) {
    CoordinateAxis axis = findCoordByType(ds, atype);
    if (axis == null) return null;
    if (axis.isScalar()) return null;
    return axis.getDimension(0);
  }
static public Dimension findDimensionByType(NetcdfDataset ds, AxisType atype) {
    CoordinateAxis axis = findCoordByType(ds, atype);
    if (axis == null) return null;
    if (axis.isScalar()) return null;
    return axis.getDimension(0);
  }
search for Dimension used by axis of given by Type.
@param ds search in this dataset's "Best" coordinate system.
@param atype search for this type of CoordinateAxis. takes the first one it finds.
@return the found CoordinateAxis' first Dimension, or null if none or scalar