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Consolidate poynting code into update_h

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This commit is contained in:
Jan Petykiewicz 2019-07-15 00:11:09 -07:00
parent fe2f4f4510
commit 1627d0da05
2 changed files with 38 additions and 30 deletions
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56
opencl_fdtd/kernels/update_h.cl
View File

@ -6,13 +6,14 @@
* common_header: Rendered contents of common.cl
* pmls: [{'axis': 'x', 'polarity': 'n', 'thickness': 8}, ...] list of pml dicts containing
* axes, polarities, and thicknesses.
* do_poynting: Whether to precalculate poynting vector components (boolean)
* do_poynting: Whether to calculate poynting vector (boolean)
* do_poynting_halves: Whether to calculate half-step poynting vectors (boolean)
* uniform_dx: If grid is uniform, uniform_dx should be the grid spacing.
* Otherwise, uniform_dx should be False and [inv_de{xyz}] arrays must be supplied as
* OpenCL args.
*
* OpenCL args:
* E, H, dt, [inv_de{xyz}], [p{xyz}{01}h{np}, Psi_{xyz}{np}_H], [oS]
* E, H, dt, [inv_de{xyz}], [p{xyz}{01}h{np}, Psi_{xyz}{np}_H], [S], [S0, S1]
*/
{{common_header}}
@ -52,7 +53,7 @@ if ({{r}} == s{{r}} - 1) {
dE{{u ~ r}} = bloch_re * dE{{u ~ r}} + bloch_im * (F{{u}}[i + p{{u}}] - F{{u}}[i]);
dE{{v ~ r}} = bloch_re * dE{{v ~ r}} + bloch_im * (F{{v}}[i + p{{v}}] - F{{v}}[i]);
}
{% endfor -%}
{%- endfor %}
{%- if do_poynting %}
@ -118,7 +119,7 @@ if ( s{{r}} > {{r}} && {{r}} >= s{{r}} - pml_{{r ~ p}}_thickness ) {
/*
* Update H
*/
{% if do_poynting -%}
{% if do_poynting or do_poynting_halves -%}
// Save old H for averaging
ftype Hx_old = Hx[i];
ftype Hy_old = Hy[i];
@ -131,25 +132,40 @@ Hy[i] -= dt * (dExz - dEzx - pHyi);
Hz[i] -= dt * (dEyx - dExy - pHzi);
{% if do_poynting -%}
/*
* Calculate unscaled S components at ??? locations
* //TODO: document S locations and types
*/
__global ftype *Sx = S + XX;
__global ftype *Sy = S + YY;
__global ftype *Sz = S + ZZ;
// Average H across timesteps
ftype aHxt = Hx[i] + Hx_old;
ftype aHyt = Hy[i] + Hy_old;
ftype aHzt = Hz[i] + Hz_old;
/*
* Calculate unscaled S components at H locations
*/
__global ftype *oSxy = oS + 0 * field_size;
__global ftype *oSyz = oS + 1 * field_size;
__global ftype *oSzx = oS + 2 * field_size;
__global ftype *oSxz = oS + 3 * field_size;
__global ftype *oSyx = oS + 4 * field_size;
__global ftype *oSzy = oS + 5 * field_size;
oSxy[i] = aEyx * aHzt;
oSxz[i] = -aEzx * aHyt;
oSyz[i] = aEzy * aHxt;
oSyx[i] = -aExy * aHzt;
oSzx[i] = aExz * aHyt;
oSzy[i] = -aEyz * aHxt;
Sx[i] = Ey[i + px] * aHzt - Ez[i + px] * aHyt;
Sy[i] = Ez[i + py] * aHxt - Ex[i + py] * aHzt;
Sz[i] = Ex[i + pz] * aHyt - Ey[i + pz] * aHxt;
{%- endif -%}
{% if do_poynting_halves -%}
/*
* Calculate unscaled S components at ??? locations
* //TODO: document S locations and types
*/
__global ftype *Sx0 = S0 + XX;
__global ftype *Sy0 = S0 + YY;
__global ftype *Sz0 = S0 + ZZ;
__global ftype *Sx1 = S1 + XX;
__global ftype *Sy1 = S1 + YY;
__global ftype *Sz1 = S1 + ZZ;
Sx0[i] = Ey[i + px] * Hz_old - Ez[i + px] * Hy_old;
Sy0[i] = Ez[i + py] * Hx_old - Ex[i + py] * Hz_old;
Sz0[i] = Ex[i + pz] * Hy_old - Ey[i + pz] * Hx_old;
Sx1[i] = Ey[i + px] * Hz[i] - Ez[i + px] * Hy[i];
Sy1[i] = Ez[i + py] * Hx[i] - Ex[i + py] * Hz[i];
Sz1[i] = Ex[i + pz] * Hy[i] - Ey[i + pz] * Hx[i];
{%- endif -%}

12
opencl_fdtd/simulation.py
View File

@ -26,7 +26,7 @@ class Simulation(object):
"""
Constructs and holds the basic FDTD operations and related fields
After constructing this object, call the (update_E, update_H, update_S) members
After constructing this object, call the (update_E, update_H) members
to perform FDTD updates on the stored (E, H, S) fields:
pmls = [{'axis': a, 'polarity': p} for a in 'xyz' for p in 'np']
@ -43,8 +43,6 @@ class Simulation(object):
# Perturb the field (i.e., add a soft current source)
sim.E[ind] += numpy.sin(omega * t * sim.dt)
event = sim.update_H([])
if sim.update_S:
event = sim.update_S([event])
event.wait()
with lzma.open('saved_simulation', 'wb') as f:
@ -112,6 +110,7 @@ class Simulation(object):
:param float_type: numpy.float32 or numpy.float64. Default numpy.float32.
:param do_poynting: If true, enables calculation of the poynting vector, S.
Poynting vector calculation adds the following computational burdens:
****INACCURATE, TODO FIXME*****
* During update_H, ~6 extra additions/cell are performed in order to spatially
average E and temporally average H. These quantities are multiplied
(6 multiplications/cell) and then stored (6 writes/cell, cache-friendly).
@ -226,12 +225,7 @@ class Simulation(object):
S_fields = OrderedDict()
if do_poynting:
S_source = jinja_env.get_template('update_s.cl').render(**jinja_args)
self.sources['S'] = S_source
self.oS = pyopencl.array.zeros(self.queue, self.E.shape + (2,), dtype=self.arg_type)
self.S = pyopencl.array.zeros_like(self.E)
S_fields[ptr('oS')] = self.oS
S_fields[ptr('S')] = self.S
J_fields = OrderedDict()
@ -257,8 +251,6 @@ class Simulation(object):
'''
self.update_E = self._create_operation(E_source, (base_fields, eps_field, pml_e_fields))
self.update_H = self._create_operation(H_source, (base_fields, pml_h_fields, S_fields))
if do_poynting:
self.update_S = self._create_operation(S_source, (base_fields, S_fields))
if bloch_boundaries:
self.update_F = self._create_operation(F_source, (bloch_fields, eps_field, pml_f_fields))
self.update_G = self._create_operation(G_source, (bloch_fields, pml_g_fields))