After download snapshot files， I read the DM's density data using Python scripts that you provided.
I found that the density data is a one-dimensional array, and we all know that density should be depend
on spatial coordinates. So, how do we relate the density to the coordinate?
The snapshot values of Density provide the values at a set of (x,y,z) positions, given by Coordinates.
You can think the of the dataset as a "scattered point set" or "scattered data", as opposed to a "grid" or "gridded data", which it is not.
So, if I want to obtain information about the density field, I should load "Density" and "Coordinates" simultaneously.
Is this right?
If you want to analyze how the density field varies in space, then yes.
Thank you, I got it!