[Gnuplot-info] keyword using with binary data matrix

[Edmond R. <ero...@gm...>]

So I can read a matrix of binary data and make an image plot like this:

plot "file" binary array=18000x4500 flipy format='%int16' with image

But I want to manipulate the points with using keyword.   But I cannot.

So I have to do this:

dump the binary file to ascii:
od -v -An -t d2 -w36000 file | tac > file.asc

Then I can plot:
plot 'file.asc' matrix using 1:2:3 with image palette
or change values:
plot 'file.asc' matrix using ($1/50):2:3 with image palette

How do I accomplish the "using" in the binary method

The reason I want to do this is so I can do math  on the numbers.

 I want to do something like this but I am not getting it right:

plot "file" binary array=18000x4500 flipy format='%int16'  using
($1/50):2:3 with image

Thanks for any clues