def time_particlescalars():
import postpic as pp
import timeit
pp.chooseCode('dummy')
dr1 = pp.readDump(0.01e6, dimensions=3)
dr2 = pp.readDump(1.0e6, dimensions=3)
ms1 = pp.MultiSpecies(dr1, 'electron')
ms2 = pp.MultiSpecies(dr2, 'electron')
testexprs = [
'x', 'x + y + z', 'gamma', 'beta', 'angle_xy', 'angle_xaxis',
'sqrt(x**2 + y**2 + z**2)', 'r_xyz',
'(gamma > 1.5) & (angle_xaxis < 0.2) & (r_xyz < 2)'
]
print('')
print(
'calculation times for n million particles, averaged over 3 calculations each...'
)
headformat = ' {:2s} | {:6s} | {:6s} | {:s}'
print(headformat.format('n', ' t', ' t/n', 'per particle quantity'))
print(headformat.format('', ' ms', 'ms/mio', ''))
def timeexpr(expr, ms):
t = timeit.Timer(lambda: ms(expr))
tc = t.timeit(number=3) / 3.0
npartmio = len(ms) / 1e6
print('{:4.2f} | {:6.2f} | {:6.2f} | "{}"'.format(
npartmio, tc * 1e3, (tc * 1e3) / npartmio, expr))
for expr in testexprs:
for ms in (ms1, ms2):
timeexpr(expr, ms)
def time_particleidsort():
import postpic as pp
import numpy as np
from timeit import default_timer as timer
pp.chooseCode('dummy')
dr = pp.readDump(1e6, dimensions=3)
ms = pp.MultiSpecies(dr, 'electron')
def timeid(ms, ids):
t0 = timer()
ms2 = ms.compress(ids)
tf = timer()
print('npart = {:.1e}, fraction_taken ={:6.2f}%, time ={:6.2f}ms' \
.format(len(ms), len(ms2)/len(ms)*100, (tf-t0)*1e3))
print('')
print('time to take a fraction of the particles by their ids')
timeid(ms, np.arange(100))
timeid(ms, np.arange(len(ms) / 20))
timeid(ms, np.arange(len(ms)))
def time_particleidfilter():
import postpic as pp
import numpy as np
from timeit import default_timer as timer
pp.chooseCode('dummy')
dr = pp.readDump(1e6, dimensions=3)
ms = pp.MultiSpecies(dr, 'electron')
def timefilter(ms, expr):
t0 = timer()
ms2 = ms.filter(expr)
tf = timer()
print('npart = {:.1e}, fraction_taken = {:6.2f}%, time = {:6.2f}ms, expr: "{}"' \
.format(len(ms), len(ms2)/len(ms)*100, (tf-t0)*1e3, expr))
print('')
print('time to filter to a fraction of the particles by expression')
timefilter(ms, 'x > 0')
timefilter(ms, 'gamma > 1.5')
timefilter(ms, '(gamma > 1.5) & (angle_xaxis < 0.2) & (r_xyz < 2)')
def setUp(self):
pp.chooseCode('dummy')
self.dr = pp.readDump(10000)
self.p = pp.MultiSpecies(self.dr, 'electron')
#################
## postpic define ###
import postpic as pp
print pp.__version__ # postpic version
pp.chooseCode('epoch')
dr = pp.readDump('Data/0020.sdf')
print(dr)
# the dumpreader knwos all the information of the simulation
print('The simulations was running on {} spatial dimensions.'.format(
dr.simdimensions()))
# if needed, postpic can be bypassed and the underlying datastructure (sdf in this case)
# can be accessed directly via keys
print(dr.keys())
print dr['Header']
print(dr.listSpecies()
) # the multispecies Object is used to access particle data
ms = pp.MultiSpecies(dr, 'electron')
# ms is representing the species "Electrons"
print(ms)
x = ms('x')
print(len(x))
# you can look at for a list of predefined values
#print pp.particle_scalars