## tref

This analysis examines the timing between trials by computing the difference between successive 'tref' values in the ndata file. This assumes trials are stored in sequential order from earliest to latest.

## Options

- simple - print statistics, including mean, SD, min, max.
- frequency - write a frequency histogram (xplot format, in percent) to the outfile.
- cumulatitve_frequency - write a plot of the cumulative frequency (xplot format) to the outfile.
## Example - make a histogram of trial start times.

# # Examine trial start times. # tref all histogram hist_nbin 100 hist_h1 0 hist_h2 20000