Re: change in handling missing data.

[Daniel J S. <dan...@ie...>]

Dmitri A. Sergatskov wrote:
> I there any way I can get an old (4.0) behavior with new
> gnuplot when plotting data files with missing data?

At one point I had created a patch for better control of this and gave a demo illustrating how to create plots with breaks in the line and simply skipping points.  I thought it was a good idea for a feature, i.e., a method of telling gnuplot how it should handle various types, but it didn't get much traction.

> 
> E.g. consider the file (say "test1.dat")
> 
> # -- begin
> 0 1
> 1 0
> NaN NaN
> 2 1
> 1 2
> # -- end
> 
> In gnuplot 4.0
> plot "test1.dat" with line
> produces plot with two segments.
> 
> With 4.1, first one has to do
> set datafile missing "NaN"
> (that still would not handle "nan")

There is patch for multiple missing, e.g., set missint "NaN" "nan" "?".

Give that a try if you need such a feature.

> but after that
> plot "test1.dat" with line
> would connect the segments along (1 0) (2 1) line.
> 
> I am not to argue wich way is better (though I would prefer
> gnuplot to handle IEEE special numbers automatically),
> I am just wondering if this behavior (to connect the segments)
> is indeed the expected one (not a bug) and if it is indeed so,
> is there any variable I can set to get old style behavior?

I say it should be configurable.  Anyway, the thread of this discussion in the past is titled:

Subject: Re: MISSING and UNDEFINED
Date: Sun, 18 Jun 2006 18:00:57 -0500
From: Daniel J Sebald <dan...@ie...>

There are some PNGs there showing the output of the demo.

Dan