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@ -27,16 +27,14 @@ electromagnetic simulations on parallel compute hardware (mainly GPUs).
* numpy
* pyopencl
* jinja2
* [fdfd_tools](https://mpxd.net/code/jan/fdfd_tools)
Optional (used for examples):
* dill (for file output)
* [gridlock](https://mpxd.net/code/jan/gridlock)
* [masque](https://mpxd.net/code/jan/masque)
* [gridlock](https://mpxd.net/gogs/jan/gridlock)
* [masque](https://mpxd.net/gogs/jan/masque)
* [fdfd_tools](https://mpxd.net/gogs/jan/fdfd_tools)
To get the code, just clone this repository:
```bash
git clone https://mpxd.net/code/jan/opencl_fdtd.git
git clone https://mpxd.net/gogs/jan/opencl_fdtd.git
```
You can install the requirements and their dependencies easily with

@ -6,13 +6,12 @@ See main() for simulation setup.
import sys
import time
import logging
import numpy
import lzma
import lzma
import dill
from opencl_fdtd import Simulation
from fdtd.simulation import Simulation
from masque import Pattern, shapes
import gridlock
import pcgen
@ -21,9 +20,6 @@ import fdfd_tools
__author__ = 'Jan Petykiewicz'
logging.basicConfig(level=logging.DEBUG)
logger = logging.getLogger(__name__)
def perturbed_l3(a: float, radius: float, **kwargs) -> Pattern:
"""
@ -124,13 +120,9 @@ def main():
eps=n_air**2,
polygons=mask.as_polygons())
logger.info('grid shape: {}'.format(grid.shape))
print('grid shape: {}'.format(grid.shape))
# #### Create the simulation grid ####
pmls = [{'axis': a, 'polarity': p, 'thickness': pml_thickness}
for a in 'xyz' for p in 'np']
#bloch = [{'axis': a, 'real': 1, 'imag': 0} for a in 'x']
bloch = []
sim = Simulation(grid.grids, do_poynting=True, pmls=pmls, bloch_boundaries=bloch)
sim = Simulation(grid.grids, do_poynting=False, pmls=[])
# Source parameters and function
w = 2 * numpy.pi * dx / wl
@ -141,41 +133,31 @@ def main():
def field_source(i):
t0 = i * sim.dt - delay
return numpy.sin(w * t0) * numpy.exp(-alpha * t0**2)
with open('sources.c', 'w') as f:
f.write(sim.sources['E'])
f.write('\n====================H======================\n')
f.write('\n==========================================\n')
f.write(sim.sources['H'])
if sim.update_S:
f.write('\n=====================S=====================\n')
f.write('\n==========================================\n')
f.write(sim.sources['S'])
if bloch:
f.write('\n=====================F=====================\n')
f.write(sim.sources['F'])
f.write('\n=====================G=====================\n')
f.write(sim.sources['G'])
# #### Run a bunch of iterations ####
# event = sim.whatever([prev_event]) indicates that sim.whatever should be queued
# immediately and run once prev_event is finished.
start = time.perf_counter()
for t in range(max_t):
e = sim.update_E([])
if bloch:
e = sim.update_F([e])
e.wait()
sim.update_E([]).wait()
ind = numpy.ravel_multi_index(tuple(grid.shape//2), dims=grid.shape, order='C') + numpy.prod(grid.shape)
sim.E[ind] += field_source(t)
# sim.buf[ind] += field_source(t)
e = sim.update_H([])
if bloch:
e = sim.update_G([e])
if sim.update_S:
e = sim.update_S([e])
e.wait()
if t % 100 == 0:
logger.info('iteration {}: average {} iterations per sec'.format(t, (t+1)/(time.perf_counter()-start)))
print('iteration {}: average {} iterations per sec'.format(t, (t+1)/(time.perf_counter()-start)))
sys.stdout.flush()
with lzma.open('saved_simulation', 'wb') as f:
@ -190,6 +172,5 @@ def main():
d['S'] = unvec(sim.S.get())
dill.dump(d, f)
if __name__ == '__main__':
main()

@ -2,14 +2,10 @@
/* Common code for E, H updates
*
* Template parameters:
* ftype type name (e.g. float or double)
* shape list of 3 ints specifying shape of fields
*/
#}
typedef {{ftype}} ftype;
/*
* Field size info
*/
@ -18,13 +14,6 @@ const size_t sy = {{shape[1]}};
const size_t sz = {{shape[2]}};
const size_t field_size = sx * sy * sz;
//Since we use i to index into Ex[], Ey[], ... rather than E[], do nothing if
// i is outside the bounds of Ex[].
if (i >= field_size) {
PYOPENCL_ELWISE_CONTINUE;
}
/*
* Array indexing
*/
@ -42,25 +31,6 @@ const size_t diy = sz;
const size_t diz = 1;
/*
* Pointer math
*/
//Pointer offsets into the components of a linearized vector-field
// (eg. Hx = H + XX, where H and Hx are pointers)
const size_t XX = 0;
const size_t YY = field_size;
const size_t ZZ = field_size * 2;
//Define pointers to vector components of each field (eg. Hx = H + XX)
__global ftype *Ex = E + XX;
__global ftype *Ey = E + YY;
__global ftype *Ez = E + ZZ;
__global ftype *Hx = H + XX;
__global ftype *Hy = H + YY;
__global ftype *Hz = H + ZZ;
/*
* Implement periodic boundary conditions
*
@ -73,9 +43,9 @@ __global ftype *Hz = H + ZZ;
* the cell x_{+1} == 0 instead, ie. px = -(sx - 1) * dix .
*/
{% for r in 'xyz' %}
int m{{r}} = - (int) di{{r}};
int p{{r}} = + (int) di{{r}};
int wrap_{{r}} = (s{{r}} - 1) * (int) di{{r}};
int m{{r}} = -1;
int p{{r}} = +1;
int wrap_{{r}} = s{{r}} - 1;
if ( {{r}} == 0 ) {
m{{r}} = wrap_{{r}};
} else if ( {{r}} == s{{r}} - 1 ) {

@ -0,0 +1,78 @@
/*
* Update E-field, including any PMLs.
*
* Template parameters:
* common_header: Rendered contents of common.cl
* pmls: [('x', 'n'), ('z', 'p'),...] list of pml axes and polarities
* pml_thickness: Number of cells (integer)
*
* OpenCL args:
* E, H, dt, eps, [p{01}e{np}, Psi_{xyz}{np}_E]
*/
{{common_header}}
////////////////////////////////////////////////////////////////////////////
__global ftype *epsx = eps + XX;
__global ftype *epsy = eps + YY;
__global ftype *epsz = eps + ZZ;
{% if pmls -%}
const int pml_thickness = {{pml_thickness}};
{%- endif %}
/*
* Precalclate derivatives
*/
ftype dHxy = Hx[i] - Hx[i + my];
ftype dHxz = Hx[i] - Hx[i + mz];
ftype dHyx = Hy[i] - Hy[i + mx];
ftype dHyz = Hy[i] - Hy[i + mz];
ftype dHzx = Hz[i] - Hz[i + mx];
ftype dHzy = Hz[i] - Hz[i + my];
/*
* PML Update
*/
// PML effects on E
ftype pExi = 0;
ftype pEyi = 0;
ftype pEzi = 0;
{% for r, p in pmls -%}
{%- set u, v = ['x', 'y', 'z'] | reject('equalto', r) -%}
{%- set psi = 'Psi_' ~ r ~ p ~ '_E' -%}
{%- if r != 'y' -%}
{%- set se, sh = '-', '+' -%}
{%- else -%}
{%- set se, sh = '+', '-' -%}
{%- endif -%}
{%- if p == 'n' %}
if ( {{r}} < pml_thickness ) {
const size_t ir = {{r}}; // index into pml parameters
{%- elif p == 'p' %}
if ( s{{r}} > {{r}} && {{r}} >= s{{r}} - pml_thickness ) {
const size_t ir = (s{{r}} - 1) - {{r}}; // index into pml parameters
{%- endif %}
const size_t ip = {{v}} + {{u}} * s{{v}} + ir * s{{v}} * s{{u}}; // linear index into Psi
{{psi ~ u}}[ip] = p0e{{p}}[ir] * {{psi ~ u}}[ip] + p1e{{p}}[ir] * dH{{v ~ r}};
{{psi ~ v}}[ip] = p0e{{p}}[ir] * {{psi ~ v}}[ip] + p1e{{p}}[ir] * dH{{u ~ r}};
pE{{u}}i {{se}}= {{psi ~ u}}[ip];
pE{{v}}i {{sh}}= {{psi ~ v}}[ip];
}
{%- endfor %}
/*
* Update E
*/
Ex[i] += dt / epsx[i] * (dHzy - dHyz + pExi);
Ey[i] += dt / epsy[i] * (dHxz - dHzx + pEyi);
Ez[i] += dt / epsz[i] * (dHyx - dHxy + pEzi);

@ -1,58 +1,36 @@
/*
* Update H-field, including any PMLs.
* Also precalculate values for poynting vector if necessary.
*
*
* Template parameters:
* 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)
* 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.
* pmls: [('x', 'n'), ('z', 'p'),...] list of pml axes and polarities
* pml_thickness: Number of cells (integer)
* do_poynting: Whether to precalculate poynting vector components (boolean)
*
* OpenCL args:
* E, H, dt, [inv_de{xyz}], [p{xyz}{01}h{np}, Psi_{xyz}{np}_H], [oS]
* E, H, dt, [p{01}h{np}, Psi_{xyz}{np}_H], [oS]
*/
{{common_header}}
////////////////////////////////////////////////////////////////////////////
{% if pmls -%}
const int pml_thickness = {{pml_thickness}};
{%- endif %}
/*
* Precalculate derivatives
*/
{%- if uniform_dx %}
ftype inv_dx = 1.0 / {{uniform_dx}};
ftype inv_dy = 1.0 / {{uniform_dx}};
ftype inv_dz = 1.0 / {{uniform_dx}};
{%- else %}
ftype inv_dx = inv_dex[x];
ftype inv_dy = inv_dey[y];
ftype inv_dz = inv_dez[z];
{%- endif %}
ftype dExy = Ex[i + py] - Ex[i];
ftype dExz = Ex[i + pz] - Ex[i];
ftype dEyx = Ey[i + px] - Ey[i];
ftype dEyz = Ey[i + pz] - Ey[i];
ftype dExy = (Ex[i + py] - Ex[i]) * inv_dy;
ftype dExz = (Ex[i + pz] - Ex[i]) * inv_dz;
ftype dEyx = (Ey[i + px] - Ey[i]) * inv_dx;
ftype dEyz = (Ey[i + pz] - Ey[i]) * inv_dz;
ftype dEzx = (Ez[i + px] - Ez[i]) * inv_dx;
ftype dEzy = (Ez[i + py] - Ez[i]) * inv_dy;
{% for bloch in bloch_boundaries -%}
{%- set r = bloch['axis'] -%}
{%- set u, v = ['x', 'y', 'z'] | reject('equalto', r) -%}
if ({{r}} == s{{r}} - 1) {
ftype bloch_re = {{bloch['real']}};
ftype bloch_im = {{bloch['imag']}};
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 -%}
ftype dEzx = Ez[i + px] - Ez[i];
ftype dEzy = Ez[i + py] - Ez[i];
{%- if do_poynting %}
@ -71,8 +49,6 @@ ftype aEzy = Ez[i + py] + Ez[i];
{%- endif %}
/*
* PML Update
*/
@ -81,35 +57,29 @@ ftype pHxi = 0;
ftype pHyi = 0;
ftype pHzi = 0;
{% for pml in pmls -%}
{%- set r = pml['axis'] -%}
{%- set p = pml['polarity'] -%}
{%- for r, p in pmls -%}
{%- set u, v = ['x', 'y', 'z'] | reject('equalto', r) -%}
{%- set psi = 'Psi_' ~ r ~ p ~ '_H' -%}
{%- if r != 'y' -%}
{%- set se, sh = '-', '+' -%}
{%- else -%}
{%- set se, sh = '+', '-' -%}
{%- endif %}
int pml_{{r ~ p}}_thickness = {{pml['thickness']}};
{%- endif -%}
{%- if p == 'n' %}
if ( {{r}} < pml_{{r ~ p}}_thickness ) {
if ( {{r}} < pml_thickness ) {
const size_t ir = {{r}}; // index into pml parameters
{%- elif p == 'p' %}
if ( s{{r}} > {{r}} && {{r}} >= s{{r}} - pml_{{r ~ p}}_thickness ) {
if ( s{{r}} > {{r}} && {{r}} >= s{{r}} - pml_thickness ) {
const size_t ir = (s{{r}} - 1) - {{r}}; // index into pml parameters
{%- endif %}
const size_t ip = {{v}} + {{u}} * s{{v}} + ir * s{{v}} * s{{u}}; // linear index into Psi
dE{{v ~ r}} *= p{{r}}2h{{p}}[ir];
dE{{u ~ r}} *= p{{r}}2h{{p}}[ir];
{{psi ~ u}}[ip] = p{{r}}0h{{p}}[ir] * {{psi ~ u}}[ip] + p{{r}}1h{{p}}[ir] * dE{{v ~ r}};
{{psi ~ v}}[ip] = p{{r}}0h{{p}}[ir] * {{psi ~ v}}[ip] + p{{r}}1h{{p}}[ir] * dE{{u ~ r}};
{{psi ~ u}}[ip] = p0h{{p}}[ir] * {{psi ~ u}}[ip] + p1h{{p}}[ir] * dE{{v ~ r}};
{{psi ~ v}}[ip] = p0h{{p}}[ir] * {{psi ~ v}}[ip] + p1h{{p}}[ir] * dE{{u ~ r}};
pH{{u}}i {{sh}}= {{psi ~ u}}[ip];
pH{{v}}i {{se}}= {{psi ~ v}}[ip];
}
@ -126,9 +96,9 @@ ftype Hz_old = Hz[i];
{%- endif %}
// H update equations
Hx[i] -= dt * (dEzy - dEyz - pHxi);
Hy[i] -= dt * (dExz - dEzx - pHyi);
Hz[i] -= dt * (dEyx - dExy - pHzi);
Hx[i] -= dt * (dEzy - dEyz + pHxi);
Hy[i] -= dt * (dExz - dEzx + pHyi);
Hz[i] -= dt * (dEyx - dExy + pHzi);
{% if do_poynting -%}
// Average H across timesteps

@ -1,11 +1,11 @@
/*
* Update E-field, including any PMLs.
*
*
* Template parameters:
* common_header: Rendered contents of common.cl
* pmls: [('x', 'n'), ('z', 'p'),...] list of pml axes and polarities
* pml_thickness: Number of cells (integer)
*
*
* OpenCL args:
* E, H, dt, S, oS
*/
@ -17,12 +17,12 @@
/*
* Calculate S from oS (pre-calculated components)
*/
*/
__global ftype *Sx = S + XX;
__global ftype *Sy = S + YY;
__global ftype *Sz = S + ZZ;
// Use unscaled S components from H locations
// Use unscaled S components from H locations
__global ftype *oSxy = oS + 0 * field_size;
__global ftype *oSyz = oS + 1 * field_size;
__global ftype *oSzx = oS + 2 * field_size;

@ -0,0 +1,253 @@
"""
Class for constructing and holding the basic FDTD operations and fields
"""
from typing import List, Dict, Callable
from collections import OrderedDict
import numpy
import jinja2
import warnings
import pyopencl
import pyopencl.array
from pyopencl.elementwise import ElementwiseKernel
from fdfd_tools import vec
__author__ = 'Jan Petykiewicz'
float4 = pyopencl.array.vec.float4
# Create jinja2 env on module load
jinja_env = jinja2.Environment(loader=jinja2.PackageLoader(__name__, 'kernels'))
class Simulation(object):
"""
Constructs and holds the basic FDTD operations and related fields
"""
E = None # type: List[pyopencl.array.Array]
H = None # type: List[pyopencl.array.Array]
S = None # type: List[pyopencl.array.Array]
eps = None # type: List[pyopencl.array.Array]
dt = None # type: float
arg_type = None # type: numpy.float32 or numpy.float64
context = None # type: pyopencl.Context
queue = None # type: pyopencl.CommandQueue
update_E = None # type: Callable[[],pyopencl.Event]
update_H = None # type: Callable[[],pyopencl.Event]
update_S = None # type: Callable[[],pyopencl.Event]
sources = None # type: Dict[str, str]
def __init__(self,
epsilon: List[numpy.ndarray],
dt: float = .99/numpy.sqrt(3),
initial_E: List[numpy.ndarray] = None,
initial_H: List[numpy.ndarray] = None,
context: pyopencl.Context = None,
queue: pyopencl.CommandQueue = None,
float_type: numpy.float32 or numpy.float64 = numpy.float32,
pml_thickness: int = 10,
pmls: List[List[str]] = None,
do_poynting: bool = True):
"""
Initialize the simulation.
:param epsilon: List containing [eps_r,xx, eps_r,yy, eps_r,zz], where each element is a Yee-shifted ndarray
spanning the simulation domain. Relative epsilon is used.
:param dt: Time step. Default is the Courant factor.
:param initial_E: Initial E-field (default is 0 everywhere). Same format as epsilon.
:param initial_H: Initial H-field (default is 0 everywhere). Same format as epsilon.
:param context: pyOpenCL context. If not given, pyopencl.create_some_context(False) is called.
:param queue: pyOpenCL command queue. If not given, pyopencl.CommandQueue(context) is called.
:param float_type: numpy.float32 or numpy.float64. Default numpy.float32.
"""
if len(epsilon) != 3:
Exception('Epsilon must be a list with length of 3')
if not all((e.shape == epsilon[0].shape for e in epsilon[1:])):
Exception('All epsilon grids must have the same shape. Shapes are {}', [e.shape for e in epsilon])
if context is None:
self.context = pyopencl.create_some_context()
else:
self.context = context
if queue is None:
self.queue = pyopencl.CommandQueue(self.context)
else:
self.queue = queue
if dt > .99/numpy.sqrt(3):
warnings.warn('Warning: unstable dt: {}'.format(dt))
elif dt <= 0:
raise Exception('Invalid dt: {}'.format(dt))
else:
self.dt = dt
def make4d(f):
g = [numpy.transpose(fi)[:,:,:,None] for fi in f]
h = g + [numpy.empty_like(g[0])]
j = numpy.concatenate(h, axis=3)
return numpy.ascontiguousarray(j, dtype=numpy.float32)
self.arg_type = float_type
self.sources = {}
ef = make4d(epsilon).astype(float_type)
self.eps = pyopencl.image_from_array(self.context,
make4d(epsilon), num_channels=4, mode='r')
self.buf = pyopencl.array.Array(self.queue, shape=epsilon.shape, dtype=float4)
if initial_E is None:
self.E = pyopencl.image_from_array(self.context,
make4d(epsilon) * 0, num_channels=4, mode='r')
else:
if len(initial_E) != 3:
Exception('Initial_E must be a list of length 3')
if not all((E.shape == epsilon[0].shape for E in initial_E)):
Exception('Initial_E list elements must have same shape as epsilon elements')
self.E = pyopencl.array.to_device(self.queue, vec(E).astype(float_type))
if initial_H is None:
self.H = pyopencl.image_from_array(self.context,
make4d(epsilon) * 0, num_channels=4, mode='r')
else:
if len(initial_H) != 3:
Exception('Initial_H must be a list of length 3')
if not all((H.shape == epsilon[0].shape for H in initial_H)):
Exception('Initial_H list elements must have same shape as epsilon elements')
self.H = pyopencl.array.to_device(self.queue, vec(H).astype(float_type))
if pmls is None:
pmls = [[d, p] for d in 'xyz' for p in 'np']
ctype = type_to_C(self.arg_type)
def ptr(arg: str) -> str:
return ctype + ' *' + arg
base_fields = OrderedDict()
common_source = jinja_env.get_template('common.cl').render(
shape=epsilon[0].shape,
)
jinja_args = {
'common_header': common_source,
'pml_thickness': pml_thickness,
'pmls': pmls,
'do_poynting': do_poynting,
}
E_source = jinja_env.get_template('update_e_full.cl').render(**jinja_args)
H_source = jinja_env.get_template('update_h_full.cl').render(**jinja_args)
self.sources['E'] = E_source
self.sources['H'] = H_source
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=float_type)
self.S = pyopencl.array.zeros_like(self.E)
S_fields = OrderedDict()
S_fields[ptr('oS')] = self.oS
S_fields[ptr('S')] = self.S
else:
S_fields = OrderedDict()
'''
PML
'''
m = (3.5, 1)
sigma_max = 0.8 * (m[0] + 1) / numpy.sqrt(1.0) # TODO: epsilon_eff (not 1.0)
alpha_max = 0 # TODO: Decide what to do about non-zero alpha
def par(x):
sigma = ((x / pml_thickness) ** m[0]) * sigma_max
alpha = ((1 - x / pml_thickness) ** m[1]) * alpha_max
p0 = numpy.exp(-(sigma + alpha) * dt)
p1 = sigma / (sigma + alpha) * (p0 - 1)
return p0, p1
xen, xep, xhn, xhp = (numpy.arange(1, pml_thickness + 1, dtype=float_type)[::-1] for _ in range(4))
xep -= 0.5
xhn -= 0.5
pml_p_names = [['p' + a + eh + np for np in 'np' for a in '01'] for eh in 'eh']
pml_e_fields = OrderedDict()
pml_h_fields = OrderedDict()
for ne, nh, pe, ph in zip(*pml_p_names, par(xen) + par(xep), par(xhn) + par(xhp)):
pml_e_fields[ptr(ne)] = pyopencl.array.to_device(self.queue, pe)
pml_h_fields[ptr(nh)] = pyopencl.array.to_device(self.queue, ph)
for pml in pmls:
uv = 'xyz'.replace(pml[0], '')
psi_base = 'Psi_' + ''.join(pml) + '_'
psi_names = [[psi_base + eh + c for c in uv] for eh in 'EH']
psi_shape = list(epsilon[0].shape)
psi_shape['xyz'.find(pml[0])] = pml_thickness
for ne, nh in zip(*psi_names):
pml_e_fields[ptr(ne)] = pyopencl.array.zeros(self.queue, tuple(psi_shape), dtype=self.arg_type)
pml_h_fields[ptr(nh)] = pyopencl.array.zeros(self.queue, tuple(psi_shape), dtype=self.arg_type)
self.pml_e_fields = pml_e_fields
self.pml_h_fields = pml_h_fields
'''
Create operations
'''
E_update = pyopencl.Program(self.context, E_source).build().update_e
H_update = pyopencl.Program(self.context, H_source).build().update_h
max_gs = E_update.get_work_group_info(pyopencl.kernel_work_group_info.WORK_GROUP_SIZE,
self.queue.device)
gs, ls = self.buf.get_sizes(self.queue, max_gs)
print('gs', gs, ls, max_gs)
def update_E(e):
e = pyopencl.enqueue_copy(self.queue, self.buf.data, self.E, offset=0, origin=(0,0,0), region=epsilon[0].shape, wait_for=e)
e = E_update(self.queue, gs, ls, self.buf.data, self.H, numpy.float32(dt), self.eps, numpy.uint32(self.buf.size), wait_for=[e])
return e
def update_H(e):
e = pyopencl.enqueue_copy(self.queue, self.E, self.buf.data, offset=0, origin=(0,0,0), region=epsilon[0].shape, wait_for=e)
e = pyopencl.enqueue_copy(self.queue, self.buf.data, self.H, offset=0, origin=(0,0,0), region=epsilon[0].shape, wait_for=[e])
e = H_update(self.queue, gs, ls, self.E, self.buf.data, numpy.float32(dt), numpy.uint32(self.buf.size), wait_for=[e])
e = pyopencl.enqueue_copy(self.queue, self.H, self.buf.data, offset=0, origin=(0,0,0), region=epsilon[0].shape, wait_for=[e])
return e
self.update_E = update_E
self.update_H = update_H
if do_poynting:
S_args = OrderedDict()
[S_args.update(d) for d in (base_fields, S_fields)]
S_update = ElementwiseKernel(self.context, operation=S_source,
arguments=', '.join(S_args.keys()))
self.update_S = lambda e: S_update(*S_args.values(), wait_for=e)
def type_to_C(float_type) -> str:
"""
Returns a string corresponding to the C equivalent of a numpy type.
Only works for float16, float32, float64.
:param float_type: e.g. numpy.float32
:return: string containing the corresponding C type (eg. 'double')
"""
if float_type == numpy.float16:
arg_type = 'half'
elif float_type == numpy.float32:
arg_type = 'float'
elif float_type == numpy.float64:
arg_type = 'double'
else:
raise Exception('Unsupported type')
return arg_type

@ -1,5 +0,0 @@
from .simulation import Simulation, type_to_C
__author__ = 'Jan Petykiewicz'
version = '0.4'

@ -1,107 +0,0 @@
/*
* Update E-field, including any PMLs.
*
* Template parameters:
* common_header: Rendered contents of common.cl
* pmls: [{'axis': 'x', 'polarity': 'n', 'thickness': 8}, ...] list of pml dicts containing
* axes, polarities, and thicknesses.
* uniform_dx: If grid is uniform, uniform_dx should be the grid spacing.
* Otherwise, uniform_dx should be False and [inv_dh{xyz}] arrays must be supplied as
* OpenCL args.
*
* OpenCL args:
* E, H, dt, eps, [p{012}e{np}, Psi_{xyz}{np}_E], [inv_dh{xyz}]
*/
{{common_header}}
////////////////////////////////////////////////////////////////////////////
__global ftype *epsx = eps + XX;
__global ftype *epsy = eps + YY;
__global ftype *epsz = eps + ZZ;
{%- if uniform_dx %}
ftype inv_dx = 1.0 / {{uniform_dx}};
ftype inv_dy = 1.0 / {{uniform_dx}};
ftype inv_dz = 1.0 / {{uniform_dx}};
{%- else %}
ftype inv_dx = inv_dhx[x];
ftype inv_dy = inv_dhy[y];
ftype inv_dz = inv_dhz[z];
{%- endif %}
/*
* Precalculate derivatives
*/
ftype dHxy = (Hx[i] - Hx[i + my]) * inv_dy;
ftype dHxz = (Hx[i] - Hx[i + mz]) * inv_dz;
ftype dHyx = (Hy[i] - Hy[i + mx]) * inv_dx;
ftype dHyz = (Hy[i] - Hy[i + mz]) * inv_dz;
ftype dHzx = (Hz[i] - Hz[i + mx]) * inv_dx;
ftype dHzy = (Hz[i] - Hz[i + my]) * inv_dy;
{% for bloch in bloch_boundaries -%}
{%- set r = bloch['axis'] -%}
{%- set u, v = ['x', 'y', 'z'] | reject('equalto', r) -%}
if ({{r}} == 0) {
ftype bloch_im = {{bloch['real']}};
ftype bloch_re = {{bloch['imag']}};
dH{{u ~ r}} = bloch_re * dH{{v ~ r}} + bloch_im * (G{{u}}[i] - G{{u}}[i + m{{u}}]);
dH{{v ~ r}} = bloch_re * dH{{v ~ r}} + bloch_im * (G{{v}}[i] - G{{v}}[i + m{{v}}]);
}
{%- endfor %}
/*
* PML Update
*/
// PML effects on E
ftype pExi = 0;
ftype pEyi = 0;
ftype pEzi = 0;
{% for pml in pmls -%}
{%- set r = pml['axis'] -%}
{%- set p = pml['polarity'] -%}
{%- set u, v = ['x', 'y', 'z'] | reject('equalto', r) -%}
{%- set psi = 'Psi_' ~ r ~ p ~ '_E' -%}
{%- if r != 'y' -%}
{%- set se, sh = '-', '+' -%}
{%- else -%}
{%- set se, sh = '+', '-' -%}
{%- endif -%}
int pml_{{r ~ p}}_thickness = {{pml['thickness']}};
{%- if p == 'n' %}
if ( {{r}} < pml_{{r ~ p}}_thickness ) {
const size_t ir = {{r}}; // index into pml parameters
{%- elif p == 'p' %}
if ( s{{r}} > {{r}} && {{r}} >= s{{r}} - pml_{{r ~ p}}_thickness ) {
const size_t ir = (s{{r}} - 1) - {{r}}; // index into pml parameters
{%- endif %}
const size_t ip = {{v}} + {{u}} * s{{v}} + ir * s{{v}} * s{{u}}; // linear index into Psi
dH{{v ~ r}} *= p{{r}}2e{{p}}[ir];
dH{{u ~ r}} *= p{{r}}2e{{p}}[ir];
{{psi ~ u}}[ip] = p{{r}}0e{{p}}[ir] * {{psi ~ u}}[ip] + p{{r}}1e{{p}}[ir] * dH{{v ~ r}};
{{psi ~ v}}[ip] = p{{r}}0e{{p}}[ir] * {{psi ~ v}}[ip] + p{{r}}1e{{p}}[ir] * dH{{u ~ r}};
pE{{u}}i {{se}}= {{psi ~ u}}[ip];
pE{{v}}i {{sh}}= {{psi ~ v}}[ip];
}
{%- endfor %}
/*
* Update E
*/
Ex[i] += dt / epsx[i] * (dHzy - dHyz + pExi);
Ey[i] += dt / epsy[i] * (dHxz - dHzx + pEyi);
Ez[i] += dt / epsz[i] * (dHyx - dHxy + pEzi);

@ -1,32 +0,0 @@
/*
* Update E-field from J field
*
* Template parameters:
* common_header: Rendered contents of common.cl
*
* OpenCL args:
* E, Jr, Ji, c, s, xmin, xmax, ymin, ymax, zmin, zmax
*/
{{common_header}}
////////////////////////////////////////////////////////////////////////////
__global ftype *Jrx = Jr + XX;
__global ftype *Jry = Jr + YY;
__global ftype *Jrz = Jr + ZZ;
__global ftype *Jix = Ji + XX;
__global ftype *Jiy = Ji + YY;
__global ftype *Jiz = Ji + ZZ;
if (x < xmin || y < ymin || z < zmin) {
PYOPENCL_ELWISE_CONTINUE;
}
if (x >= xmax || y >= ymax || z >= zmax) {
PYOPENCL_ELWISE_CONTINUE;
}
Ex[i] += c * Jrx[i] + s * Jix[i];
Ey[i] += c * Jry[i] + s * Jiy[i];
Ez[i] += c * Jrz[i] + s * Jiz[i];

@ -1,376 +0,0 @@
"""
Class for constructing and holding the basic FDTD operations and fields
"""
from typing import List, Dict, Callable
from collections import OrderedDict
import numpy
import jinja2
import warnings
import pyopencl
import pyopencl.array
from pyopencl.elementwise import ElementwiseKernel
from fdfd_tools import vec
__author__ = 'Jan Petykiewicz'
# Create jinja2 env on module load
jinja_env = jinja2.Environment(loader=jinja2.PackageLoader(__name__, 'kernels'))
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
to perform FDTD updates on the stored (E, H, S) fields:
pmls = [{'axis': a, 'polarity': p} for a in 'xyz' for p in 'np']
sim = Simulation(grid.grids, do_poynting=True, pmls=pmls)
with open('sources.c', 'w') as f:
f.write('{}'.format(sim.sources))
for t in range(max_t):
sim.update_E([]).wait()
# Find the linear index for the center point, for Ey
ind = numpy.ravel_multi_index(tuple(grid.shape//2), dims=grid.shape, order='C') + \
numpy.prod(grid.shape) * 1
# 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:
dill.dump(fdfd_tools.unvec(sim.E.get(), grid.shape), f)
Code in the form
event2 = sim.update_H([event0, event1])
indicates that the update_H operation should be prepared immediately, but wait for
event0 and event1 to occur (i.e. previous operations to finish) before starting execution.
event2 can then be used to prepare further operations to be run after update_H.
"""
E = None # type: pyopencl.array.Array
H = None # type: pyopencl.array.Array
S = None # type: pyopencl.array.Array
eps = None # type: pyopencl.array.Array
dt = None # type: float
inv_dxes = None # type: List[pyopencl.array.Array]
arg_type = None # type: numpy.float32 or numpy.float64
context = None # type: pyopencl.Context
queue = None # type: pyopencl.CommandQueue
update_E = None # type: Callable[[List[pyopencl.Event]], pyopencl.Event]
update_H = None # type: Callable[[List[pyopencl.Event]], pyopencl.Event]
update_S = None # type: Callable[[List[pyopencl.Event]], pyopencl.Event]
update_J = None # type: Callable[[List[pyopencl.Event]], pyopencl.Event]
sources = None # type: Dict[str, str]
def __init__(self,
epsilon: List[numpy.ndarray],
pmls: List[Dict[str, int or float]],
bloch_boundaries: List[Dict[str, int or float]] = (),
dxes: List[List[numpy.ndarray]] or float = None,
dt: float = None,
initial_fields: Dict[str, List[numpy.ndarray]] = None,
context: pyopencl.Context = None,
queue: pyopencl.CommandQueue = None,
float_type: numpy.float32 or numpy.float64 = numpy.float32,
do_poynting: bool = True,
do_fieldsrc: bool = False):
"""
Initialize the simulation.
:param epsilon: List containing [eps_r,xx, eps_r,yy, eps_r,zz], where each element is a Yee-shifted ndarray
spanning the simulation domain. Relative epsilon is used.
:param pmls: List of dicts with keys:
'axis': One of 'x', 'y', 'z'.
'direction': One of 'n', 'p'.
'thickness': Number of layers, default 8.
'epsilon_eff': Effective epsilon to match to. Default 1.0.
'mu_eff': Effective mu to match to. Default 1.0.
'ln_R_per_layer': Desired (ln(R) / thickness) value. Default -1.6.
'm': Polynomial grading exponent. Default 3.5.
'ma': Exponent for alpha. Default 1.
:param bloch_boundaries: List of dicts with keys:
'axis': One of 'x', 'y', 'z'.
'real': Real part of bloch phase factor (i.e. real(exp(i * phase)))
'imag': Imaginary part of bloch phase factor (i.e. imag(exp(i * phase)))
:param dt: Time step. Default is min(dxes) * .99/sqrt(3).
:param initial_fields: Dict with optional keys ('E', 'H', 'F', 'G') containing initial values for the
specified fields (default is 0 everywhere). Fields have same format as epsilon.
:param context: pyOpenCL context. If not given, pyopencl.create_some_context(False) is called.
:param queue: pyOpenCL command queue. If not given, pyopencl.CommandQueue(context) is called.
: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:
* 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).
* update_S performs a discrete cross product using the precalculated products
from update_H. This is not nice to the cache and similar to e.g. update_E
in complexity.
* GPU memory requirements are approximately doubled, since S and the intermediate
products must be stored.
"""
if initial_fields is None:
initial_fields = {}
self.shape = epsilon[0].shape
self.arg_type = float_type
self.sources = {}
self._create_context(context, queue)
self._create_eps(epsilon)
if dxes is None:
dxes = 1.0
if isinstance(dxes, (float, int)):
uniform_dx = dxes
min_dx = dxes
else:
uniform_dx = False
self.inv_dxes = [self._create_field(1 / dxn) for dxn in dxes[0] + dxes[1]]
min_dx = min(min(dxn) for dxn in dxes[0] + dxes[1])
max_dt = min_dx * .99 / numpy.sqrt(3)
if dt is None:
self.dt = max_dt
elif dt > max_dt:
warnings.warn('Warning: unstable dt: {}'.format(dt))
elif dt <= 0:
raise Exception('Invalid dt: {}'.format(dt))
else:
self.dt = dt
self.E = self._create_field(initial_fields.get('E', None))
self.H = self._create_field(initial_fields.get('H', None))
if bloch_boundaries:
self.F = self._create_field(initial_fields.get('F', None))
self.G = self._create_field(initial_fields.get('G', None))
for pml in pmls:
pml.setdefault('thickness', 8)
pml.setdefault('epsilon_eff', 1.0)
pml.setdefault('mu_eff', 1.0)
pml.setdefault('ln_R_per_layer', -1.6)
pml.setdefault('m', 3.5)
pml.setdefault('cfs_alpha', 0)
pml.setdefault('ma', 1)
ctype = type_to_C(self.arg_type)
def ptr(arg: str) -> str:
return ctype + ' * restrict ' + arg
base_fields = OrderedDict()
base_fields[ptr('E')] = self.E
base_fields[ptr('H')] = self.H
base_fields[ctype + ' dt'] = self.dt
if uniform_dx == False:
inv_dx_names = ['inv_d' + eh + r for eh in 'eh' for r in 'xyz']
for name, field in zip(inv_dx_names, self.inv_dxes):
base_fields[ptr(name)] = field
eps_field = OrderedDict()
eps_field[ptr('eps')] = self.eps
if bloch_boundaries:
base_fields[ptr('F')] = self.F
base_fields[ptr('G')] = self.G
bloch_fields = OrderedDict()
bloch_fields[ptr('E')] = self.F
bloch_fields[ptr('H')] = self.G
bloch_fields[ctype + ' dt'] = self.dt
bloch_fields[ptr('F')] = self.E
bloch_fields[ptr('G')] = self.H
common_source = jinja_env.get_template('common.cl').render(
ftype=ctype,
shape=self.shape,
)
jinja_args = {
'common_header': common_source,
'pmls': pmls,
'do_poynting': do_poynting,
'bloch': bloch_boundaries,
'uniform_dx': uniform_dx,
}
E_source = jinja_env.get_template('update_e.cl').render(**jinja_args)
H_source = jinja_env.get_template('update_h.cl').render(**jinja_args)
self.sources['E'] = E_source
self.sources['H'] = H_source
if bloch_boundaries:
bloch_args = jinja_args.copy()
bloch_args['do_poynting'] = False
bloch_args['bloch'] = [{'axis': b['axis'],
'real': b['imag'],
'imag': b['real']}
for b in bloch_boundaries]
F_source = jinja_env.get_template('update_e.cl').render(**bloch_args)
G_source = jinja_env.get_template('update_h.cl').render(**bloch_args)
self.sources['F'] = F_source
self.sources['G'] = G_source
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()
if do_fieldsrc:
J_source = jinja_env.get_template('update_j.cl').render(**jinja_args)
self.sources['J'] = J_source
self.Ji = pyopencl.array.zeros_like(self.E)
self.Jr = pyopencl.array.zeros_like(self.E)
J_fields[ptr('Jr')] = self.Jr
J_fields[ptr('Ji')] = self.Ji
'''
PML
'''
pml_e_fields, pml_h_fields = self._create_pmls(pmls)
if bloch_boundaries:
pml_f_fields, pml_g_fields = self._create_pmls(pmls)
'''
Create operations
'''
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))
if do_fieldsrc:
args = OrderedDict()
[args.update(d) for d in (base_fields, J_fields)]
var_args = [ctype + ' ' + v for v in 'cs'] + ['uint ' + r + m for r in 'xyz' for m in ('min', 'max')]
update = ElementwiseKernel(self.context, operation=J_source,
arguments=', '.join(list(args.keys()) + var_args))
self.update_J = lambda e, *a: update(*args.values(), *a, wait_for=e)
def _create_pmls(self, pmls):
ctype = type_to_C(self.arg_type)
def ptr(arg: str) -> str:
return ctype + ' *' + arg
pml_e_fields = OrderedDict()
pml_h_fields = OrderedDict()
for pml in pmls:
a = 'xyz'.find(pml['axis'])
sigma_max = -pml['ln_R_per_layer'] / 2 * (pml['m'] + 1)
kappa_max = numpy.sqrt(pml['mu_eff'] * pml['epsilon_eff'])
alpha_max = pml['cfs_alpha']
def par(x):
scaling = ((x / (pml['thickness'])) ** pml['m'])
sigma = scaling * sigma_max
kappa = 1 + scaling * (kappa_max - 1)
alpha = ((1 - x / pml['thickness']) ** pml['ma']) * alpha_max
p0 = numpy.exp(-(sigma / kappa + alpha) * self.dt)
p1 = sigma / (sigma + kappa * alpha) * (p0 - 1)
p2 = 1/kappa
return p0, p1, p2
xe, xh = (numpy.arange(1, pml['thickness'] + 1, dtype=self.arg_type)[::-1] for _ in range(2))
if pml['polarity'] == 'p':
xe -= 0.5
elif pml['polarity'] == 'n':
xh -= 0.5
pml_p_names = [['p' + pml['axis'] + i + eh + pml['polarity'] for i in '012'] for eh in 'eh']
for name_e, name_h, pe, ph in zip(pml_p_names[0], pml_p_names[1], par(xe), par(xh)):
pml_e_fields[ptr(name_e)] = pyopencl.array.to_device(self.queue, pe)
pml_h_fields[ptr(name_h)] = pyopencl.array.to_device(self.queue, ph)
uv = 'xyz'.replace(pml['axis'], '')
psi_base = 'Psi_' + pml['axis'] + pml['polarity'] + '_'
psi_names = [[psi_base + eh + c for c in uv] for eh in 'EH']
psi_shape = list(self.shape)
psi_shape[a] = pml['thickness']
for ne, nh in zip(*psi_names):
pml_e_fields[ptr(ne)] = pyopencl.array.zeros(self.queue, tuple(psi_shape), dtype=self.arg_type)
pml_h_fields[ptr(nh)] = pyopencl.array.zeros(self.queue, tuple(psi_shape), dtype=self.arg_type)
return pml_e_fields, pml_h_fields
def _create_operation(self, source, args_fields):
args = OrderedDict()
[args.update(d) for d in args_fields]
update = ElementwiseKernel(self.context, operation=source,
arguments=', '.join(args.keys()))
return lambda e: update(*args.values(), wait_for=e)
def _create_context(self, context: pyopencl.Context = None,
queue: pyopencl.CommandQueue = None):
if context is None:
self.context = pyopencl.create_some_context()
else:
self.context = context
if queue is None:
self.queue = pyopencl.CommandQueue(self.context)
else:
self.queue = queue
def _create_eps(self, epsilon: List[numpy.ndarray]):
if len(epsilon) != 3:
raise Exception('Epsilon must be a list with length of 3')
if not all((e.shape == epsilon[0].shape for e in epsilon[1:])):
raise Exception('All epsilon grids must have the same shape. Shapes are {}', [e.shape for e in epsilon])
if not epsilon[0].shape == self.shape:
raise Exception('Epsilon shape mismatch. Expected {}, got {}'.format(self.shape, epsilon[0].shape))
self.eps = pyopencl.array.to_device(self.queue, vec(epsilon).astype(self.arg_type))
def _create_field(self, initial_value: List[numpy.ndarray] = None):
if initial_value is None:
return pyopencl.array.zeros_like(self.eps)
else:
if len(initial_value) != 3:
Exception('Initial field value must be a list of length 3')
if not all((f.shape == self.shape for f in initial_value)):
Exception('Initial field list elements must have same shape as epsilon elements')
return pyopencl.array.to_device(self.queue, vec(initial_value).astype(self.arg_type))
def type_to_C(float_type) -> str:
"""
Returns a string corresponding to the C equivalent of a numpy type.
Only works for float16, float32, float64.
:param float_type: e.g. numpy.float32
:return: string containing the corresponding C type (eg. 'double')
"""
if float_type == numpy.float16:
arg_type = 'half'
elif float_type == numpy.float32:
arg_type = 'float'
elif float_type == numpy.float64:
arg_type = 'double'
else:
raise Exception('Unsupported type')
return arg_type

@ -2,7 +2,7 @@ numpy
h5py
pyopencl
jinja2
-e git+https://mpxd.net/code/jan/float_raster.git@release#egg=float_raster
-e git+https://mpxd.net/code/jan/gridlock.git@release#egg=gridlock
-e git+https://mpxd.net/code/jan/masque.git@release#egg=masque
-e git+https://mpxd.net/code/jan/fdfd_tools.git@master#egg=fdfd_tools
-e git+https://mpxd.net/gogs/jan/float_raster.git@release#egg=float_raster
-e git+https://mpxd.net/gogs/jan/gridlock.git@release#egg=gridlock
-e git+https://mpxd.net/gogs/jan/masque.git@release#egg=masque
-e git+https://mpxd.net/gogs/jan/fdfd_tools.git@master#egg=fdfd_tools

@ -1,30 +0,0 @@
#!/usr/bin/env python3
from setuptools import setup, find_packages
import opencl_fdtd
with open('README.md', 'r') as f:
long_description = f.read()
setup(name='opencl_fdtd',
version=opencl_fdtd.version,
description='OpenCL FDTD solver',
long_description=long_description,
long_description_content_type='text/markdown',
author='Jan Petykiewicz',
author_email='anewusername@gmail.com',
url='https://mpxd.net/code/jan/opencl_fdtd',
packages=find_packages(),
package_data={
'opencl_fdfd': ['kernels/*']
},
install_requires=[
'numpy',
'pyopencl',
'jinja2',
'fdfd_tools>=0.3',
],
extras_require={
},
)
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