So, here I am trying to plot heatmaps in gnuplot. I have a matrix-formatted text file (with row and column headers), and the command I am using to plot it is
plot "file.txt" matrix rowheaders columnheaders using 1:2:3 w image notitle
The output is this graph: 
Obviously, the X and Y labels are useless like this. I believe the problem here is that gnuplot is extracting all labels from the file and plotting them. How would I go about reducing the amount of clutter in here, e.g. plotting every 10th label or so?
Thanks in advance.