visad/src/main/java/ucar/nc2/iosp/grid/GridVariable.java
public int showMissingSummary(Formatter f) {
    int count = 0;
    int total = recordTracker.length;

    for (int i = 0; i < total; i++) {
      if (recordTracker[i] == null)
        count++;
    }

    f.format("  MISSING= %d / %d for %s%n", count, total, name);
    return count;
  }
public int showMissingSummary(Formatter f) {
    int count = 0;
    int total = recordTracker.length;

    for (int i = 0; i < total; i++) {
      if (recordTracker[i] == null)
        count++;
    }

    f.format("  MISSING= %d / %d for %s%n", count, total, name);
    return count;
  }
Dump out the missing data as a summary

@param f write to this
@return number of missing levels