splot behaves differently from tplot

[si14]

> tplot                                                                                                                                        master [42fdd42] untracked

tplot - a tool for drawing timing diagrams.
        See http://www.haskell.org/haskellwiki/Timeplot
Usage: tplot [-o OFILE] [-of {png|pdf|ps|svg}] [-or 640x480]
             -if IFILE [-tf TF] 
             [{+|-}k Pat1 '[+Suf1] Kind1' {+|-}k Pat2 '[+Suf2] Kind2' ...] [{+|-}dk '[+Suf] KindN']
             [-fromTime TIME] [-toTime TIME] [-baseTime TIME]
  --version  - show version information

si14@si14-laptop:~/repos/splot (*)
> splot                                                                                                                                        master [42fdd42] untracked
splot: Input file not specified

[jkff]

What version are you using? My splot behaves in the expected way.