Gnuplot pm3d not plotting all data

Question

I have a text file that looks like this:

0 0 1
0 1 -1

1 0 -1
1 1 1

I\'m plotting this with pm3d with the number of colours in the

Answer 1

The pm3d option is averaging your z value between the points that you have defined, this is standard and I am not sure it can be changed without formatting your data. What you can do is to unset the pm3d option and plot with the with image style. I actually find this preferable because the figures produced are of much smaller size (byte-wise speaking).

With your set of data:

plot "data" with image

Yields what you want: