Re: [Gnuplot-info] plot by filtering some lines

[William Xu <wil...@gm...>]

Hans-Bernhard Bröker <HBB...@t-...> writes:

> William Xu wrote:
>>>From the manual, i manage to do the filtering with the following trick: 
>
> ... what filtering?  You've removed all context, so it's hard to know 
> what you might be talking about.

For example, 

,----
| #a b c 
| 1 3 5
| 1 4 9
| 2 3 7
| 1 2 6
`----

I'd like to draw (b, c) points where a == 1.

>> ,----
>> | plot 'result.log' using ($4 == 1 $3 : 1/0):5 title '1 session' with linespoints
>> `----
>> 
>> However, seems `with linespoints' part doesn't work, it display as
>> dots. What's the problem here?
>
> The problem is that you hwave way too many undefined points in your 
> input.  Lines can only be drawn between consequtive valid points.  Looks 
> like there are no two valid points without an invalid one between them, 
> in your entire file.  

The data file should be okay. Anyway, i find i can embed shell command
into plot, so using awk, it draws linespoints as expected.

,----
| plot "< awk '{ if($4==1) print $1, $2, $3, $4, $5}' result.log" using 3:5 title '1 session' with linespoints
`----

which should do the same as: 

>> ,----
>> | plot 'result.log' using ($4 == 1 $3 : 1/0):5 title '1 session' with linespoints
>> `----

right?

-- 
William