Re: zooming of inline data

[Ethan M. <merritt@u.washington.edu>]

On Thursday 30 August 2007 14:23, Petr Mikulik wrote:
> I thought that Ethan has already committed his patch
>     [ 1723715 ] Refresh plot or zoom without re-reading data
> and that it was released in 4.2.1, but it is not the case.
> What was the reason of not putting it into cvs (see 2007-07-01 04:36)?
> 
> 
> There is also this patch
>     [ 1745865 ] store raw data to refresh plot without rereading files
> which is somehow similar in results (but caches all datafiles).
> 
> 
> So, how to continue? Zooming of inline data is really important (and not 
> only for Octave users).

Good question.  I don't know the correct answer.

My patch 1723715 is imperfect, as Daniel Sebald pointed out.
One imperfection is that is does not allow toggling log scale axes.
One positive feature is that it requires no additional internal
storage or data structures.

Daniel's alternative patch  174865 creates a new set of internal storage
buffers and saves all the input data for later re-use.  I do not
like the overhead, but I concede the point that it provides 
identical parsing and plotting behaviour for fresh or stored data.
I have not had time to look at the code quality, nor have I tested
it on real data.

We also discussed the option of re-writing the log scale code so that
the original data is stored rather than rescaled data.
That is, the log scaling would be applied at the time of plotting
rather than at the time the data is read in. This would remove the major
limitation of patch 1723715, but at the cost of rewriting all the
code that references log scaling.  I.e., high risk of breakage.
I think this is an attractive long-term alternative, but it doesn't
address the immediate needs of Octave users.


-- 
Ethan A Merritt