GNUPLOT: 2d histogram from set of points

Question

I have a pairs of the points with their weights:

#x  y  w
0.111342 0.478917 0.232487 
0.398107 1.79559 0.221714 
0.200731 2.58651 0.0776068 
0.0967412 1.49904 0.0645355 
6.17638 8.63101 0.715604 
0.306128 3.10917 0.0984595 
0.340707 3.19344 0.10669 
7.18627 8.59859 0.835751 
8.56 9.63894 0.888065 
5.14272 6.86074 0.749587 
0.747202 3.812 0.196013 
8.71891 10.1355 0.860232 
0.346714 1.45895 0.237647 
5.21932 8.84491 0.590094 
9.42138 12.2082 0.771725 
0.215627 2.42317 0.0889856 

How to plot nice 2d histogram image with color bar? I found nice density map description but I don't wont to go via python. I there way to use only gnuplot scripting?

Answer 1

It's best to use an external histogramming tool, but you can achieve something similar in gnuplot via:

set pm3d at b      # draw on bottom, not as 3d surface
set view map       # don't do a 3-d looking plot
set dgrid 100,100  # grid of 100x100 pixels
splot 'dat.txt' w pm3d