Re: [Gnuplot-info] "set key noautotitle" ignored on explicit column name?

[Ethan A M. <eam...@gm...>]

On Wednesday, 12 March 2014 01:21:36 PM Rhys Ulerich wrote:
> Why does the first plot below obey "set key noautotitle" while the
> second one ignores it?
> 
> $ gnuplot -V
> gnuplot 4.6 patchlevel 5
> 
> $ file ~/.gnuplot  # No rcfile magic up my sleeve
> /h2/rhys/.gnuplot: cannot open `/h2/rhys/.gnuplot' (No such file or directory)
> 
> $ cat data
> x
> 1
> 2
> 3
> 
> $ gnuplot
> gnuplot> set key noautotitle
> gnuplot> plot 'data' using 0:1    # First
> gnuplot> plot 'data' using 0:"x"  # Second
> gnuplot> set key autotitle
> gnuplot> plot 'data' using 0:1    # Third
> gnuplot> plot 'data' using 0:"x"  # Fourth
> 
> Why does this third plot autotitle "correctly" from the plot
> specification while the fourth behaves as if I said "set key autotitle
> columnheader"?

Because in the 4th plots you tell it to read the columnheader
(in order to find column "x") and so the input data must necessarily
_have_ columnheaders.  That is the same thing that 
you are telling it with "set key autotitle columnheader".
Same request - same result.

Therefore plot #4 shows the intended behaviour.

Plot #2  - maybe not.
 
On the other hand, plot command #1 is just wrong.
You luck out because the column header happens to be
a string that cannot be parsed as valid numeric input,
so the first line is treated as containing an undefined/missing
data value.   If your column header were "3rd_base" or something
like that, plot commands #1 would produce an incorrect plot
with a spurious initial data point at 3.

> I find the behaviors on the second and fourth plots to be buggy, but
> perhaps I'm misunderstanding something implicit about using a named
> column.
> - Rhys

I don't see anything remotely buggy about #3 or #4.
Plots #1 should probably print a warning.

Plot #2 is arguably a demonstration that we should have two
distinct commands that don't really exist yet:
   set noautotitle columnheader
   set autotitle nocolumnheader


		Ethan