"with image" and "using"

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

Hi. I'm seeing a strange behavior. I THINK it's a bug, but maybe not?
Note that the below is about "with image": we have z vs. (x,y) and NOT
"with rgbimage" where we have (r,g,b) vs (x,y).

I can plot a simple 3x3 grid of data:

  set view map
  splot '-' matrix notitle with image
  0.0 1.0 4.0
  1.0 2.0 5.0
  4.0 5.0 8.0

  e

This works, and uses the default implicit x and y ranges: integers
starting at 0. I can adjust this with "using". For instance I can
linearly scale the x axis like this:

  set view map
  splot '-' matrix using ($1*10):2:3 notitle with image
  0.0 1.0 4.0
  1.0 2.0 5.0
  4.0 5.0 8.0

  e

This works too. I can also feed in binary data instead of ascii. The
example without "using" looks like this:

  set view map
  splot '-' binary array=(3,3) format="%double" notitle with image
  [ binary data ]

(I'm omitting the actual data here; the functional version including the
data is in the attachment). This works too, and produces the same plot,
as expected. However, if I try to scale the x axis with the "using"
clause as before, it does NOT work:

  set view map
  splot '-' binary array=(3,3) format="%double" using ($1*10):2:3 notitle with image
  [ binary data ]

(again, the full script is attached). In the binary-no-using case I see
gnuplot try to read 72 bytes of binary data. This makes sense since 72 =
3*3*sizeof(double). In the binary-using case, however, I see gnuplot try
to read 216 bytes intead. this is 72*3. But there aren't that many bytes
available, so it barfs.

As I user I was not expecting this, especially since the other 3 cases
work. Thoughts?