Re: multiple plot lines with plot '-'

[<pl...@pi...>]

On 05/14/12 14:52, Allin Cottrell wrote:
> On Mon, 14 May 2012, Mojca Miklavec wrote:
>
>> On Mon, May 14, 2012 at 8:21 AM, <pl...@pi...> wrote:
>>> HI,
>>>
>>> I am plotting some data from a data file with four columns to produce
>>> three plot lines.
>>>
>>> set timefmt "%d.%m.%y:%H:%M"; set xdata time
>>> plot  "fast.log" using 1:2 t "systolic" w l,  "fast.log" using 1:3 t
>>> "diastolic" w l, "fast.log" using 1:4 t "pulse" w l
>>>
>>> To save having a separate gnuplot script file I was trying to put these
>>> two lines at the head of the data and use the plot '-' feature. But this
>>> involves reading the data three times and I can't see how to do it.
>>>
>>> Before suggesting ways this could be improved I was wondering whether I
>>> was missing a trick.
>>
>> Simply use empty quotation marks:
>> plot  "fast.log" using 1:2 t "systolic" w l,  "" using ...
>
> This doesn't work in the context plotter specified, namely when you
> replace the data file "fast.log" with inline data in the plot file,
> using "plot '-'".
>
> I too would be interested to know if there's any way to avoid repeating
> the inline data when plotting multiple lines.
>
> Allin Cottrell

Thanks Allin,

unless someone points out a trick we're missing perhaps the plot '-' 
feature could be extended to act in same way as a named file.

It seems that  plot '-', '-'  already has a defined behaviour of reading 
two subsequent sets of inline data so I guess that has to stay as it is. 
This seems to be the effect of using plot "" after plot '-' too.

This an unfortunate asymmetry in the behaviour when compared to named 
files but it's long established and probably should stay as it is.

So could another flag like plot '--' be used to indicate rereading of 
the inline data rather than continuing at the next block of inline data ?

regards, Peter.