Re: "with image" and "using"

[Dima K. <gn...@di...>]

sfeam <me...@uw...> writes:

> My thoughts are that it's worse than you describe.
>
> A related limitation is that it is not possible to combine 'using' with
> reading an image data from a binary file for any purpose other than
> "with image".  Not for generic binary files and not for specific known file types.
>
> For example you might want to plot a histogram of intensity values in the
> blue component of an RGB image file.  Logically this would mean extracting
> the values in "column 5", assuming a mapping to x:y:R:G:B as documented.
> The logical gnuplot command would be something like
>
>     plot 'foo.jpg' binary filetype=jpeg using 5 smooth freq with boxes
>
> Nothing of the sort works.
>
> I see no consistency in the mapping of binary data to "columns". This
> has annoyed me for a long time but the problem seems so intrinsic to
> the way the program currently works that I don't see a way to change
> it.

That's too bad. I just played with the code a bit, and indeed it doesn't
behave in an obvious way, and I can't figure it out without dumping more
time into it. I might do that at some later point, but in the meantime I
guess the current behavior will do.

Thanks for looking into it.
dima