public Array readData(Variable v2, Section section) throws IOException, InvalidRangeException {
    // Vgroup vgroup = (Vgroup) v2.getSPobject();
    // Range scanRange = section.getRange(0);
    // Range radialRange = section.getRange(1);
    // Range gateRange = section.getRange(2);

    Array data = Array.factory(v2.getDataType().getPrimitiveClassType(), section.getShape());
    IndexIterator ii = data.getIndexIterator();

    List<List<Ray>> groups;
    String shortName = v2.getShortName();
    if (shortName.startsWith("Reflectivity")) groups = volScan.getReflectivityGroups();
    else if (shortName.startsWith("Velocity")) groups = volScan.getVelocityGroups();
    else if (shortName.startsWith("TotalPower")) groups = volScan.getTotalPowerGroups();
    else if (shortName.startsWith("Width")) groups = volScan.getWidthGroups();
    else if (shortName.startsWith("DiffReflectivity"))
      groups = volScan.getDifferentialReflectivityGroups();
    else throw new IllegalStateException("Illegal variable name = " + shortName);

    if (section.getRank() == 2) {
      Range radialRange = section.getRange(0);
      Range gateRange = section.getRange(1);
      List<Ray> lli = groups.get(0);
      readOneScan(lli, radialRange, gateRange, ii);
    } else {
      Range scanRange = section.getRange(0);
      Range radialRange = section.getRange(1);
      Range gateRange = section.getRange(2);
      for (int i = scanRange.first(); i <= scanRange.last(); i += scanRange.stride()) {
        readOneScan(groups.get(i), radialRange, gateRange, ii);
      }
    }
    return data;
  }
  public Array readData(Variable v2, Section section) throws IOException, InvalidRangeException {
    Vgroup vgroup = (Vgroup) v2.getSPobject();

    Range scanRange = section.getRange(0);
    Range radialRange = section.getRange(1);
    Range gateRange = section.getRange(2);

    Array data = Array.factory(v2.getDataType().getPrimitiveClassType(), section.getShape());
    IndexIterator ii = data.getIndexIterator();

    for (int i = scanRange.first(); i <= scanRange.last(); i += scanRange.stride()) {
      Cinrad2Record[] mapScan = vgroup.map[i];
      readOneScan(mapScan, radialRange, gateRange, vgroup.datatype, ii);
    }

    return data;
  }