[Gnuplot-info] with image error msg: "Number of pixels cannot be factored"

[Philipp K. J. <ja...@ie...>]

When trying to plot the following file:

1	1	1
1	2	2
2	1	3
2	2	4
3	3	1
3	1	0
3	2	0
1	3	0
2	3	0

using 

plot "file" u 1:2:3 w imag

I received the following warning message:
        warning: Number of pixels cannot be factored into integers
	matching grid. N = 9  K = 2 

The plot showed just the borders and the
colorbox, but none of my data.

What am I doing wrong? And what's the 
meaning of the quantities N and K in
the error msg? (I don't seem to find 
any info in the docs about them.)

Thanks!

Best,

		Ph.