I am making a map with gnuplot. But, I find that the length of X axis is not equal with the Y axis. For example, the length of X from 0 to 10 is 20 pixels while 15 pixels in Y axis from 1 to 10. Can I directly set X and Y axis same in length? Thanks.

This sets the unit length of both axes to the same value:
Here is an excerpt from the documentation:



Try with
This should set the dimension (not scale) of the two axis to be equal. 

