def ut12frame(treq, ind, ut1_unix):
if treq is None:  <EOL><INDENT>return<EOL><DEDENT>treq = atleast_1d(treq)<EOL><INDENT>handle human specified string scalar case<EOL><DEDENT>if treq.size == <NUM_LIT:1>:<EOL><INDENT>treq = datetime2unix(treq[<NUM_LIT:0>])<EOL>
Given treq, output index(ces) to extract via rawDMCreader
treq: scalar or vector of ut1_unix time (seconds since Jan 1, 1970)
ind: zero-based frame index corresponding to ut1_unix, corresponding to input data file.