Hi, I have a question about G2P in APIC while reading the given codes.
In the slides of G2P(APIC), Cp is updated with something like 4/dx^2. While in the given code “pic_vs_apic.py”, Cp is given by
new_C += 4 * weight * g_v.outer_product(dpos) * inv_dx
Only one “inv_dx” is presented here. I wonder why “inv_dx” is used here rather than “inv_dx**2”.
Thanks and looking forward to your reply.