01_packed_mode_test.py

import taichi as ti

ti.init(arch=ti.cpu, packed=True)

a = ti.field(dtype=ti.i32)
ti.root.dense(ti.ij, (2, 3)).dense(ti.ij, (2,3)).place(a)

@ti.kernel
def fill():
    for i, j in a:
        base = ti.get_addr(a.snode, [0, 0])
        a[i, j] = int(ti.get_addr(a.snode, [i, j]) - base) // 4


fill()
print(a.to_numpy())

02_row_vs_column.py

import taichi as ti

ti.init(arch=ti.cpu, packed=True)

a = ti.field(dtype=ti.i32)
b = ti.field(dtype=ti.i32)

ti.root.dense(ti.i, 2).dense(ti.j, 3).place(a) # row-major
ti.root.dense(ti.j, 3).dense(ti.i, 2).place(b) # column-major

@ti.kernel
def fill(f: ti.template()):
    for i, j in f:
        base = ti.get_addr(f.snode, [0,0])
        f[i,j] = int(ti.get_addr(f.snode, [i,j]) - base) // 4


fill(a)
fill(b)

print(f"row-major: \n {a.to_numpy()}")
print(f"column-major: \n {b.to_numpy()}")