Now, that's a real challenge. Agnes Martin (1912-2004 — sigh, how can she be dead???!!!) spent her life on the grid, that quintessentially modernist creature.
In her own words:
"Nature is like parting a curtain, you go into it. I want to draw a
certain response like this. Not a specific response but that quality of
response from people when they leave themselves behind, often
experienced in nature — an experience of simple joy, this simple,
direct going into a field of vision as you would cross an empty beach to
look at the ocean.(Agnes Martin, New York,
1993, p. 109).
What exactly is she mapping? We can only know by looking at the paintings — ideally, in the flesh.
But here's a photo anyway: Starlight, watercolor and ink on paper, 1963