cdm/src/main/java/ucar/ma2/Range.java
public int getFirstInInterval(int start) {
    if (start > last()) return -1;
    if (start <= first) return first;
    if (stride == 1) return start;
    int offset = start - first;
    int i = offset / stride;
    i = (offset % stride == 0) ? i : i + 1; // round up
    return first + i * stride;
  }
public int getFirstInInterval(int start) {
    if (start > last()) return -1;
    if (start <= first) return first;
    if (stride == 1) return start;
    int offset = start - first;
    int i = offset / stride;
    i = (offset % stride == 0) ? i : i + 1; // round up
    return first + i * stride;
  }
Find the first element in a strided array after some index start.
Return the smallest element k in the Range, such that <ul>
<li>k >= first
<li>k >= start
<li>k <= last
<li>k = element of this Range
</ul>

@param start starting index
@return first in interval, else -1 if there is no such element.