cdm/src/main/java/ucar/nc2/ft2/coverage/CoordAxisHelper.java
private int findSingleHit(double target) {
    int hits = 0;
    int idxFound = -1;
    int n = axis.getNcoords();
    for (int i = 0; i < n; i++) {
      if (contains(target, i)) {
        hits++;
        idxFound = i;
      }
    }
    if (hits == 1) return idxFound;
    if (hits == 0) return -1;
    return -hits;
  }
private int findSingleHit(double target) {
    int hits = 0;
    int idxFound = -1;
    int n = axis.getNcoords();
    for (int i = 0; i < n; i++) {
      if (contains(target, i)) {
        hits++;
        idxFound = i;
      }
    }
    if (hits == 1) return idxFound;
    if (hits == 0) return -1;
    return -hits;
  }
return index if only one match, if no matches return -1, if > 1 match return -nhits