[Gnuplot-info] Date difference

[<be...@fa...>]

Hi,

I was trying to plot the difference in days between to dates. With the
info in this newsgroup I made a script using timecolumn() and column()
that works fine on my examples. However, now it seems not to work if
timecolumn() is given a column number >=4. What am I missing here? I am
using Gnuplot 4.0 path 0 on Linux.

Please, see example below.
Thanks for your help.

Best regards,
Bernd

set timefmt "%Y-%m-%d"

#Expected points are plotted
plot "-" using ($1):((timecolumn(3)-timecolumn(2))/(24*3600))
1	2005-06-02	2005-06-03
3	2005-06-10	2005-06-12
e
pause-1

#Error is returned: x range is invalid
#When we delete column 3 and ask for timecolumn(3) it works...
plot "-" using ($1):(timecolumn(4))
1	4	12	2005-06-03
3	5	15	2005-06-12
e
pause-1