[Gnuplot-bugs] differences between u 1:2 and using ($1):($2)

[Javier G. <j.a...@gm...>]

Hi,

I have found out that when creating a plot with time format in the x-axis,
using comands

set timefmt "%s"
set xdata time

there is a difference in the use of the column specifier.

There is no problem by using the reduced form.

plot "timedata" u 1:2

works perfectly,

however when using as

plot 'timedata" using ($1):($2)

the time data is not properly interpreted.

This is a problem when somebody wants to create this kind of plot by
producing a mathematical operation in the y-axis,

as it could be ...

plot 'timedata" using ($1):(($2)*($3))

cheers,
  Javier