function?[trct]=depth2time（ztrcztzcurvedt）
%?DEPTH2TIME:?Convert?a?trace?from?depth?to?time?by?a?simple?stretch
%
%?[trcz]=depth2time（ztrcztzcurvedt）
%
%?DEPTH2TIME?converts?a?single?trace?from?depth?to?time.?The?conversion?is
%?specified?by?a?time-depth?curve?that?is?stored?in?a?two-column?matrix.
%?The?first?column?is?a?list?of?times?and?the?second?is?a?list?of?
%?corresponding?depths.?The?times?can?be?either?one-way?or?two-way?and
%?need?only?be?consistent?with?the?time-coordinate?vector?of?the?input.
%?Between?points?in?the?time-depth?curve?times?are?interpolated?linearly.
%?Note?that?this?function?does?not?apply?an?antialias?filter.?It?is
%?up?to?the?user?to?ensure?that?dz?is?sufficiently?small?to?preclude
%?aliasing.
%?
%?ztrc?...?the?trace?in?depth
%?z?...?d