I have data from an experiment that is sampling responses between 59 to 60 hz. There is no way to predict the drop-down in sampling rate throughout the experiment which runs for 18 minutes.

Each of the sampled responses are numbered from 1 to N (for total number of rows) showing relative passage of time, stored in variable 'frame'. I also have a unix time stamp marking absolute time stored in 'unixtime'. But unixtime is reported in whole integers & not in fractional units. For example:

1376925380 may be repeated 59 times;
1376925381 may be repeated 60 times in the data file.
I would like to create a new variable that tracks each consecutive frame (or sampled response) from 1 to 60 or from 1 to 59, as the case may be, for each given unixtime stamp in SPSS. See the desired re-arrangement below. Any help w/ appropriate SPSS-syntax is appreciated!

unixtime    newframe
1376925380  1
1376925380  2
1376925380  3
1376925380  4
1376925380  5   
1376925380  6
....
1376925380  58
1376925380  59
1376925381  1
1376925381  2
1376925381  3
1376925381  4
....        ....
1376925381  60
1376925382  1
1376925382  2
....