create a smooth surface using x,y,z data gnuplot

I have a file which contains x,y,z data. Actually, the data is:

x = latitude y = longitude z= Depth

I want to create a smooth surface but I have no idea how to do it. Could anybody give me some hints to do it?

UPDATE

So, the data looks like the next lines:

-62.323 19.242 58.7 -62.213 10.886 120.2 -62.329 10.797 71.9 -62.383 10.690 1.3 -60.121 11.567 24.5 -60.481 12.894 3 -62.118 10.944 69.1 -60.825 15.803 25.5 -61.792 16.227 148.3 -63.288 10.817 28.4 -59.092 14.344 3 -61.836 11.217 67.7 -61.346 14.799 191.2 -61.152 15.427 126.6 -60.959 16.035 55.8 -61.364 15.283 151.6 -62.071 11.222 109.5 -62.420 10.672 72.1 -60.267 14.009 13.1 -60.604 14.033 65.4 -60.623 10.307 42.4 -62.272 17.936 75 -60.464 13.908 40.9 -60.722 14.701 181.5 -62.125 10.911 47.1 -62.530 10.544 5.2 -60.170 12.752 71.5 -60.929 14.635 87.9 -62.279 10.936 74.3 -62.267 10.767 75.8 -60.708 10.440 36.2 -62.440 10.463 2.6 -62.477 10.217 3 -62.399 10.651 58.7 

There are more points. The idea is to create the plane or surface along the depth (the third column).

1 Answer

Basically, you plot surfaces with the splot command. data_file contains your example data points.

gnuplot> splot 'data_file' 

As you want a smooth surface, you have to specify that you want gnuplot to interpolate the data. Here is an example, see for some others.

gnuplot> set hidden3d gnuplot> set dgrid3d 50,50 qnorm 2 gnuplot> splot 'data_file' with lines 

There are a lot of parameters you can adjust, e.g. what interpolation function is used. As it is very hard to cover all here in a general answer, I want to recommend to start with the documentation about splot and set dgrid3d.