I cannot test your particular example, but I have mine that looked like:
...
plot "test.dat" using ..., \
"" using ($1-100000):2:3 with labels rotate left notitle
...
... where the "rotate left" part was taken from the OP.
Well, I didn't have much luck finding info about "alignment" or "justification" of labels on the net; so I tried to look in the online gnuplot help. Basically, the relevant stuff is under help set label - I'm not sure exactly how I got down to it, but here is my command log below;
$ gnuplot
...
G N U P L O T
Version 4.4 patchlevel 2
...
Terminal type set to 'wxt'
gnuplot> help with labels
Sorry, no help for 'with labels'
gnuplot> help with
Functions and data may be displayed in one of a large number of styles.
The `with` keyword provides the means of selection.
Syntax:
with { {linestyle | ls }
...
where is one of
lines dots steps errorbars xerrorbar xyerrorlines
points impulses fsteps errorlines xerrorlines yerrorbars
linespoints labels ...
...
gnuplot> help labels
The `labels` style reads coordinates and text from a data file and places
the text string at the corresponding 2D or 3D position. 3 or 4 input columns
of basic data are required. ....
3 columns: x y string # 2D version
...
See also `datastrings`, `set style data`.
gnuplot> help set label
Arbitrary labels can be placed on the plot using the `set label` command.
Syntax:
set label {} {""} {at }
{left | center | right}
{norotate | rotate {by }}
...
By default, the text is placed flush left against the point x,y,z. To adjust
the way the label is positioned with respect to the point x,y,z, add the
justification parameter, which may be `left`, `right` or `center`,
indicating that the point is to be at the left, right or center of the text.
Labels outside the plotted boundaries are permitted but may interfere with
axis labels or other text.
If `rotate` is given, the label is written vertically (if the terminal can do
so, of course). If `rotate by ` is given, conforming terminals will
try to write the text at the specified angle; non-conforming terminals will
treat this as vertical text.
The relevant parts are bolded; and they explain one misconception I had - seeing the rotate left in the OP example, I thought left is attribute of rotate, however it isn't - left is a separate justification parameter, while rotate is a separate rotation keyword (i.e. rotate left doesn't mean "rotate counterclockwise 90 degrees" as I initially thought).
If that is so, one can then invert those two keywords:
...
plot "test.dat" using ..., \
"" using ($1-100000):2:3 with labels left rotate notitle
...
... and get the exact same output plot. And if finally we replace left with right, as in:
...
plot "test.dat" using ..., \
"" using ($1-100000):2:3 with labels right rotate notitle
...
... we can see that the label is still rotated "left" (counterclockwise 90 degrees) - however, it is now right-aligned to the position.
Well, hope this helps,
Cheers!
