cdf_files=[
'3541-a1h.cdf'
'3531-a1h.cdf'
'u664en2.cdf '
'u668en2.cdf '
'u672en2.cdf '
'u676en2.cdf '
'u680en2.cdf '];
[start,stop]=overlap(cdf_files);
[wlp,jd]=getvlp(cdf_files,start,stop);
