def __init__(self,base_dir, cal=None, cal_each_mask=False):
'''
A Decoder for a Vector Coded Aperture Measurment System
Parameters
-----------
base_dir : str, or `unipath.Path`
the base directory which holds all data
cal: `skrf.Calibration` object or None
the calibration template that is copied for each mask's
calibration. The `measurements` attribute provided by
the calibraition template is never used, only the `ideals`.
if None, then no calibration is performed
cal_each_mask : bool
should a calibration be performed for each mask? If True, this
requires that `cal` represents a calibration template, for
which the `measurements` are provided for each mask dir
'''
self.base_dir = Path( base_dir)
self.cal = cal
self.cal_each_mask = cal_each_mask
# determine rank
max_dec = max([int(d) for d in self.decs.keys()])
self.rank = int(sqrt(len('{0:b}'.format(max_dec))))
self.frequency = rf.ran(str(self.decs.values()[0])).values()[0].frequency
def decode_with_rotation(dir_, f="634ghz", cal=None, averaging=True):
"""
decode a hadamard-encoded dataset at a given frequency
Examples
----------
f = '634ghz'
dir_= '../CAI/Bar Image/hadamard_2/Primary'
a = decode(dir_=dir_, f = f,averaging =True)
matshow(rf.complex_2_db(a))
cb = colorbar()
#clim(-26,-25)
grid(0)
"""
hexs = os.listdir(dir_)
# determine resolution and rank
res = int(sqrt(len(hexs)))
rank = int(log2(res))
# calculate inverse hadamard-delta transform`T`
# this can be pre-computed
bins = [hex2bin(k, rank=rank) for k in hexs]
T = array([array(list(k), dtype=int) for k in bins])
T_inv = inv(T)
# create measurement frame `M` in hadamard space.
M = []
for k in hexs:
b = array(list(hex2bin(k, rank=rank)), dtype=int)
n = rf.ran(dir_ + "/" + k)
if cal is not None:
n = cal.apply_cal_to_list(n)
if averaging:
n = rf.average(n.values())
else:
n = n[sorted(n.keys())[-1]]
s = n[f].s[0, 0, 0] # pull out single complex number
m = s * b
M.append(m)
M = array(M)
# transform the frame `M` in hadamard space to
# frame `A` in delta space
A = T_inv.dot(M)
# pixels lay along the diagonal.
A_diag = array([A[k, k] for k in range(res ** 2)])
# reshape the diagonal matrix into the image
a = A_diag.reshape(res, res)
return a, A
def decode_with_rotation(dir_, f='634ghz', cal=None, averaging=True):
'''
decode a hadamard-encoded dataset at a given frequency
Examples
----------
f = '634ghz'
dir_= '../CAI/Bar Image/hadamard_2/Primary'
a = decode(dir_=dir_, f = f,averaging =True)
matshow(rf.complex_2_db(a))
cb = colorbar()
#clim(-26,-25)
grid(0)
'''
hexs = os.listdir(dir_)
#determine resolution and rank
res = int(sqrt(len(hexs)))
rank = int(log2(res))
# calculate inverse hadamard-delta transform`T`
# this can be pre-computed
bins = [hex2bin(k, rank=rank) for k in hexs]
T = array([array(list(k), dtype=int) for k in bins])
T_inv = inv(T)
# create measurement frame `M` in hadamard space.
M = []
for k in hexs:
b = array(list(hex2bin(k, rank=rank)), dtype=int)
n = rf.ran(dir_ + '/' + k)
if cal is not None:
n = cal.apply_cal_to_list(n)
if averaging:
n = rf.average(n.values())
else:
n = n[sorted(n.keys())[-1]]
s = n[f].s[0, 0, 0] # pull out single complex number
m = s * b
M.append(m)
M = array(M)
# transform the frame `M` in hadamard space to
# frame `A` in delta space
A = T_inv.dot(M)
# pixels lay along the diagonal.
A_diag = array([A[k, k] for k in range(res**2)])
#reshape the diagonal matrix into the image
a = A_diag.reshape(res, res)
return a, A
def raw_ntwk_of(self,dec,name):
'''
raw ntwk for a given mask, or pixel
'''
if isinstance(dec, tuple):
ntwks = [self.raw_ntwk_of(k,name) for k in self.pixel2decs(*dec)]
return rf.average(ntwks)
ntwk = rf.ran(str(self.decs[dec]), contains=name).values()[0]
return ntwk
def da(self):
'''
a xarray.DataArray object representing the entire data-set
'''
# return cached value if it exists
if self._da is not None:
return self._da
hexs= self.hexs
#determine resolution and rank
res = int(sqrt(len(hexs)))
rank = int(log2(res))
M=[] # will hold weighted masks
for k in hexs:
n = rf.ran(self.dir_+'/'+k)
if self.cal is not None:
n = self.cal.apply_cal_to_list(n)
if self.averaging:
n = rf.average(n.values())
else:
n = n[sorted(n.keys())[-1]]
s = n.s[:,0,0].reshape(-1,1,1) # pull out single complex number
m = hex2mask(k,rank=rank)
#copy mask allong frequency dimension
m = expand_dims(m,0).repeat(s.shape[0],0)
m = m*s
M.append(m)
M= array(M)
n.frequency.unit='ghz'
da = DataArray(M, coords=[('mask_hex',hexs),
('f_ghz',n.frequency.f_scaled),
('row',range(res)),
('col',range(res))])
self._da = da # cache it
return da
def da(self):
'''
a xarray.DataArray object representing the entire data-set
'''
# return cached value if it exists
if self._da is not None and caching:
return self._da
hexs = self.hexs
res = self.res
rank = self.rank
M = [] # will hold weighted masks
for k in hexs:
n = rf.ran(self.dir_ + '/' + k)
if self.cal is not None:
n = self.cal.apply_cal_to_list(n)
if self.averaging:
n = rf.average(n.values())
else:
n = n[sorted(n.keys())[-1]]
s = n.s[:, 0, 0].reshape(-1, 1,
1) # pull out single complex number
m = hex2mask(k, rank=rank)
#copy mask allong frequency dimension
m = expand_dims(m, 0).repeat(s.shape[0], 0)
m = m * s
M.append(m)
M = array(M)
n.frequency.unit = 'ghz'
da = DataArray(M,
coords=[('mask_hex', hexs),
('f_ghz', n.frequency.f_scaled),
('row', range(res)), ('col', range(res))])
if caching:
self._da = da
return da
def cal_of(self,dec):
'''
Calibration for a given mask, or pixel
'''
##TODO: for no-cal or static cal this could be only calculated
# once to improve performance
if self.cal is None:
freq = self.frequency
n = len(freq)
coefs ={'directivity':zeros(n),
'source match': zeros(n),
'reflection tracking':ones(n)}
cal =OnePort.from_coefs(frequency=freq, coefs=coefs)
return cal
if not self.cal_each_mask:
return self.cal
else:
# we want a calibration for each mask, so create the calbration
# for this mask,or pixel
cal = deepcopy(self.cal)
ideals = cal.ideals
if isinstance(dec, tuple):
# decode the measurements
measured =[]
for ideal in ideals:
m = self.raw_ntwk_of(dec,ideal.name)
measured.append(m)
else:
measured = rf.ran(self.decs[dec]).values()
cal.measured, cal.ideals = rf.align_measured_ideals(measured,ideals)
cal.name = str(dec)
return cal
def frequency(self):
return rf.ran(self.dir_+'/'+self.hexs[0]).values()[0].frequency
def _get_ntwk_dict(self):
try:
return rf.ran(self.input_dir)
except(OSError):
return {}
def frequency(self):
return rf.ran(self.dir_ + '/' + self.hexs[0]).values()[0].frequency
