def evalfreq(self, t):
"""Return the freq at time t, computed with this polyco entry"""
dt = (data2longdouble(t) - self.tmid.value) * MIN_PER_DAY
s = data2longdouble(0.0)
for i in range(1, self.ncoeff):
s += data2longdouble(i) * self.coeffs[i] * dt**(i - 1)
freq = self.f0 + s / 60.0
return freq
def __init__(self, tmid, mjdspan, rph_int, rph_frac, f0, ncoeff, coeffs):
self.tmid = data2longdouble(tmid) * u.day
self.mjdspan = data2longdouble(mjdspan / MIN_PER_DAY) * u.day
self.tstart = self.tmid - (self.mjdspan / 2)
self.tstop = self.tmid + (self.mjdspan / 2)
self.f0 = data2longdouble(f0)
self.ncoeff = ncoeff
self.rphase = Phase(rph_int, rph_frac)
self.coeffs = data2longdouble(coeffs)
def evalfreqderiv(self, t):
"""Return the frequency derivative at time t."""
dt = (data2longdouble(t) - self.tmid.value) * MIN_PER_DAY
s = data2longdouble(0.0)
for i in range(2, self.ncoeff):
# Change to long double
s += (data2longdouble(i) * data2longdouble(i - 1) *
self.coeffs[i] * dt**(i - 2))
freqd = s / (60.0 * 60.0)
return freqd
def evalabsphase(self, t):
"""Return the phase at time t, computed with this polyco entry"""
dt = (data2longdouble(t) - self.tmid.value) * data2longdouble(1440.0)
# Compute polynomial by factoring out the dt's
phase = Phase(self.coeffs[self.ncoeff -
1]) # Compute phase using two long double
for i in range(self.ncoeff - 2, -1, -1):
pI = Phase(dt * phase.int)
pF = Phase(dt * phase.frac)
c = Phase(self.coeffs[i])
phase = pI + pF + c
# Add DC term
phase += self.rphase + Phase(dt * 60.0 * self.f0)
return phase
def eval_spin_freq(self, t):
"""
Polyco evaluate spin frequency for a time array.
Parameters
---------
t: numpy.ndarray or a single number.
An time array in MJD. Time sample should be in order
Returns
---------
out: numpy array of long double frequencies in Hz
Polyco evaluated spin frequency at time t.
FREQ(Hz) = F0 + (1/60)*(COEFF(2) + 2*DT*COEFF(3) + 3*DT^2*COEFF(4) + ...)
"""
if not isinstance(t, np.ndarray) and not isinstance(t, list):
t = np.array([t])
entryIndex = self.find_entry(t)
poly_result = data2longdouble(np.zeros(len(t)))
dt = (data2longdouble(t) -
self.polycoTable[entryIndex]["tmid"]) * MIN_PER_DAY
for ii, (tt, eidx) in enumerate(zip(dt, entryIndex)):
coeffs = self.polycoTable["entry"][eidx].coeffs
coeffs = data2longdouble(range(len(coeffs))) * coeffs
coeffs = coeffs[::-1][:-1]
poly_result[ii] = np.polyval(coeffs, tt)
spinFreq = np.array([
self.polycoTable["entry"][eidx].f0 +
poly_result[ii] / data2longdouble(60.0)
for ii, eidx in zip(range(len(t)), entryIndex)
])
return spinFreq
def __init__(self, tmid, mjdspan, rphaseInt, rphaseFrac, f0, ncoeff,
coeffs, obs):
self.tmid = tmid * u.day
self.mjdspan = mjdspan * u.day
self.tstart = data2longdouble(
self.tmid) - data2longdouble(self.mjdspan) / 2.0
self.tstop = data2longdouble(
self.tmid) + data2longdouble(self.mjdspan) / 2.0
self.rphase = Phase(rphaseInt, rphaseFrac)
self.f0 = data2longdouble(f0)
self.ncoeff = ncoeff
self.coeffs = data2longdouble(coeffs)
self.obs = obs
def generate_polycos(
self,
model,
mjdStart,
mjdEnd,
obs,
segLength,
ncoeff,
obsFreq,
maxha=12.0,
method="TEMPO",
numNodes=20,
):
"""
Generate the polyco data.
Parameters
----------
model : TimingModel
TimingModel to generate the Polycos with parameters
setup.
mjdStart : float / numpy longdouble
Start time of polycos in mjd
mjdEnd : float / numpy longdouble
Ending time of polycos in mjd
obs : str
Observatory code
segLength : int
Length of polyco segement [minutes]
ncoeff : int
Number of coefficents
obsFreq : float
Observing frequency [MHz]
maxha : float optional. Default 12.0
Maximum hour angle. Only 12.0 is supported for now.
method : string optional ["TEMPO", "TEMPO2", ...] Default TEMPO
Method to generate polycos. Only the TEMPO method is supported for now.
numNodes : int optional. Default 20
Number of nodes for fitting. It cannot be less then the number of
coefficents.
Return
---------
A polyco table.
"""
mjdStart = data2longdouble(mjdStart)
mjdEnd = data2longdouble(mjdEnd)
segLength = int(segLength)
obsFreq = float(obsFreq)
# Use the planetary ephemeris specified in the model, if available.
if model.EPHEM.value is not None:
ephem = model.EPHEM.value
else:
log.info(
"No ephemeris specified in model, using DE421 to generate polycos"
)
ephem = "DE421"
if maxha != 12.0:
raise ValueError("Maximum hour angle != 12.0 is not supported.")
# Make sure the number of nodes is bigger than number of coeffs.
if numNodes < ncoeff:
numNodes = ncoeff + 1
mjdSpan = data2longdouble(segLength / MIN_PER_DAY)
# Generate "nice" MJDs for consistency with what tempo2 does
tmids = np.arange(
int(mjdStart * 24) * 60,
int(mjdEnd * 24) * 60 + segLength, segLength)
tmids = data2longdouble(tmids) / MIN_PER_DAY
# generate the ploynomial coefficents
if method == "TEMPO":
entryList = []
# Using tempo1 method to create polycos
# If you want to disable the progress bar, add disable=True to the tqdm() call.
for tmid in tqdm(tmids):
tStart = tmid - mjdSpan / 2
tStop = tmid + mjdSpan / 2
nodes = np.linspace(tStart, tStop, numNodes)
toaMid = toa.get_TOAs_list(
[
toa.TOA((np.modf(tmid)[1], np.modf(tmid)[0]),
obs=obs,
freq=obsFreq)
],
ephem=ephem,
)
refPhase = model.phase(toaMid, abs_phase=True)
# Create node toas(Time sample using TOA class)
toaList = [
toa.TOA(
(np.modf(toaNode)[1], np.modf(toaNode)[0]),
obs=obs,
freq=obsFreq,
) for toaNode in nodes
]
toas = toa.get_TOAs_list(toaList, ephem=ephem)
ph = model.phase(toas, abs_phase=True)
dt = (nodes - tmid) * MIN_PER_DAY
rdcPhase = ph - refPhase
rdcPhase = rdcPhase.int - (dt * model.F0.value *
60.0) + rdcPhase.frac
dtd = dt.astype(float) # Truncate to double
rdcPhased = rdcPhase.astype(float)
coeffs = np.polyfit(dtd, rdcPhased, ncoeff - 1)[::-1]
date, hms = Time(tmid, format="mjd", scale="utc").iso.split()
yy, mm, dd = date.split("-")
date = dd + "-" + MONTHS[int(mm) - 1] + "-" + yy[-2:]
hms = float(hms.replace(":", ""))
entry = PolycoEntry(
tmid,
segLength,
refPhase.int,
refPhase.frac,
model.F0.value,
ncoeff,
coeffs,
)
entry_dict = OrderedDict()
entry_dict["psr"] = model.PSR.value
entry_dict["date"] = date
entry_dict["utc"] = hms
entry_dict["tmid"] = tmid
entry_dict["dm"] = model.DM.value
entry_dict["doppler"] = 0.0
entry_dict["logrms"] = 0.0
entry_dict["mjd_span"] = segLength
entry_dict["t_start"] = entry.tstart
entry_dict["t_stop"] = entry.tstop
entry_dict["obs"] = obs
entry_dict["obsfreq"] = obsFreq
if model.is_binary:
binphase = model.orbital_phase(toaMid, radians=False)[0]
entry_dict["binary_phase"] = binphase
b = model.get_components_by_category()["pulsar_system"][0]
entry_dict["f_orbit"] = 1 / b.PB.value
entry_dict["entry"] = entry
entryList.append(entry_dict)
pTable = table.Table(entryList, meta={"name": "Polyco Data Table"})
self.polycoTable = pTable
if len(self.polycoTable) == 0:
raise ValueError("Zero polycos found for table")
else:
raise NotImplementedError(
"Only TEMPO method has been implemented.")
def tempo_polyco_table_reader(filename):
"""Read tempo style polyco file to an astropy table.
Tempo style: The polynomial ephemerides are written to file 'polyco.dat'.
Entries are listed sequentially within the file. The file format is::
==== ======= ============================================
Line Columns Item
==== ======= ============================================
1 1-10 Pulsar Name
11-19 Date (dd-mmm-yy)
20-31 UTC (hhmmss.ss)
32-51 TMID (MJD)
52-72 DM
74-79 Doppler shift due to earth motion (10^-4)
80-86 Log_10 of fit rms residual in periods
2 1-20 Reference Phase (RPHASE)
21-38 Reference rotation frequency (F0)
39-43 Observatory number
44-49 Data span (minutes)
50-54 Number of coefficients
55-75 Observing frequency (MHz)
76-80 Binary phase
3* 1-25 Coefficient 1 (COEFF(1))
26-50 Coefficient 2 (COEFF(2))
51-75 Coefficient 3 (COEFF(3))
==== ======= ============================================
* Subsequent lines have three coefficients each, up to NCOEFF
One polyco file could include more then one entry.
The pulse phase and frequency at time T are then calculated as::
DT = (T-TMID)*1440
PHASE = RPHASE + DT*60*F0 + COEFF(1) + DT*COEFF(2) + DT^2*COEFF(3) + ....
FREQ(Hz) = F0 + (1/60)*(COEFF(2) + 2*DT*COEFF(3) + 3*DT^2*COEFF(4) + ....)
Parameters
----------
filename : str
Name of the input poloco file.
References
----------
http://tempo.sourceforge.net/ref_man_sections/tz-polyco.txt
"""
entries = []
with open(filename, "r") as f:
line = f.readline()
while line != "":
# First line
fields = line.split()
psrname = fields[0]
date = fields[1]
utc = float(fields[2])
tmid = np.longdouble(fields[3])
dm = float(fields[4])
doppler = float(fields[5])
logrms = float(fields[6])
# Second line
fields = f.readline().split()
refPhaseInt, refPhaseFrac = fields[0].split(".")
refPhaseInt = np.longdouble(refPhaseInt)
refPhaseFrac = np.longdouble("." + refPhaseFrac)
if refPhaseInt < 0:
refPhaseFrac = -refPhaseFrac
refF0 = np.longdouble(fields[1])
obs = fields[2]
mjdspan = int(fields[3])
nCoeff = int(fields[4])
obsfreq = float(fields[5])
try:
binary_phase = float(fields[6])
f_orbit = float(fields[7])
is_binary = True
except IndexError:
is_binary = False
# Read coefficients
coeffs = []
for i in range(-(nCoeff // -3)):
line = f.readline()
for c in line.split():
coeffs.append(data2longdouble(c))
coeffs = np.array(coeffs)
entry = PolycoEntry(tmid, mjdspan, refPhaseInt, refPhaseFrac,
refF0, nCoeff, coeffs)
entry_dict = OrderedDict()
entry_dict["psr"] = psrname
entry_dict["date"] = date
entry_dict["utc"] = utc
entry_dict["tmid"] = tmid
entry_dict["dm"] = dm
entry_dict["doppler"] = doppler
entry_dict["logrms"] = logrms
entry_dict["mjd_span"] = mjdspan
entry_dict["t_start"] = entry.tstart
entry_dict["t_stop"] = entry.tstop
entry_dict["obs"] = obs
entry_dict["obsfreq"] = obsfreq
if is_binary:
entry_dict["binary_phase"] = binary_phase
entry_dict["f_orbit"] = f_orbit
entry_dict["entry"] = entry
entries.append(entry_dict)
line = f.readline()
pTable = table.Table(entries, meta={"name": "Polyco Data Table"})
return pTable
def generate_polycos(
self,
model,
mjdStart,
mjdEnd,
obs,
segLength,
ncoeff,
obsFreq,
maxha=12.0,
method="TEMPO",
numNodes=20,
):
"""
Generate the polyco data.
Parameters
---------
model : TimingModel
TimingModel to generate the Polycos with parameters
setup.
mjdStart : float / nump longdouble
Start time of polycos in mjd
mjdEnd : float / nump longdouble
Ending time of polycos in mjd
obs : str
Observatory code
segLength : float
Length of polyco segement [unit: minutes]
ncoeff : int
number of coefficents
obsFreq : float
observing frequency [unit: MHz]
maxha : float optional. Default 12.0
Maximum hour angle
method : string optional ['TEMPO','TEMPO2',...] Default TEMPO
Method to generate polycos. Only the TEMPO method is supported for now.
numNodes : int optional. Default 20
Number of nodes for fitting. It cannot be less then the number of
coefficents.
Return
---------
A polyco table.
"""
mjdStart = data2longdouble(mjdStart) * u.day
mjdEnd = data2longdouble(mjdEnd) * u.day
timeLength = mjdEnd - mjdStart
segLength = data2longdouble(segLength) * u.min
obsFreq = float(obsFreq)
month = [
"Jan",
"Feb",
"Mar",
"Apr",
"May",
"Jun",
"Jul",
"Aug",
"Sep",
"Oct",
"Nov",
"Dec",
]
# Alocate memery
coeffs = data2longdouble(np.zeros(ncoeff))
entryList = []
entryIntvl = np.arange(mjdStart.value, mjdEnd.value,
segLength.to("day").value)
if entryIntvl[-1] < mjdEnd.value:
entryIntvl = np.append(entryIntvl, mjdEnd.value)
# Make sure the number of nodes is bigger then number of coeffs.
if numNodes < ncoeff:
numNodes = ncoeff + 1
# generate the ploynomial coefficents
if method == "TEMPO":
# Using tempo1 method to create polycos
for i in range(len(entryIntvl) - 1):
tStart = entryIntvl[i]
tStop = entryIntvl[i + 1]
nodes = np.linspace(tStart, tStop, numNodes)
tmid = ((tStart + tStop) / 2.0) * u.day
toaMid = toa.get_TOAs_list([
toa.TOA(
(np.modf(tmid.value)[1], np.modf(tmid.value)[0]),
obs=obs,
freq=obsFreq,
)
])
refPhase = model.phase(toaMid)
mjdSpan = ((tStop - tStart) * u.day).to("min")
# Create node toas(Time sample using TOA class)
toaList = [
toa.TOA(
(np.modf(toaNode)[1], np.modf(toaNode)[0]),
obs=obs,
freq=obsFreq,
) for toaNode in nodes
]
toas = toa.get_TOAs_list(toaList)
ph = model.phase(toas)
dt = (nodes * u.day - tmid).to("min") # Use constant
rdcPhase = ph - refPhase
rdcPhase = (rdcPhase.int -
(dt.value * model.F0.value * 60.0) * u.cycle +
rdcPhase.frac)
dtd = dt.value.astype(float) # Truncate to double
rdcPhased = rdcPhase.astype(float)
coeffs = np.polyfit(dtd, rdcPhased, ncoeff - 1)
coeffs = coeffs[::-1]
midTime = Time(int(tmid.value),
np.modf(tmid.value)[0],
format="mjd",
scale="utc")
date, hms = midTime.iso.split()
yy, mm, dd = date.split("-")
date = dd + "-" + month[int(mm) - 1] + "-" + yy[2:4]
hms = hms.replace(":", "")
entry = PolycoEntry(
tmid.value,
mjdSpan.to("day").value,
refPhase.int,
refPhase.frac,
model.F0.value,
ncoeff,
coeffs,
obs,
)
entryList.append((
model.PSR.value,
date,
hms,
tmid.value,
model.DM.value,
0.0,
0.0,
0.0,
mjdSpan.to("day").value,
tStart,
tStop,
obs,
obsFreq,
entry,
))
pTable = table.Table(
rows=entryList,
names=(
"psr",
"date",
"utc",
"tmid",
"dm",
"doppler",
"logrms",
"binary_phase",
"mjd_span",
"t_start",
"t_stop",
"obs",
"obsfreq",
"entry",
),
meta={"name": "Polyco Data Table"},
)
self.polycoTable = pTable
if len(self.polycoTable) == 0:
raise ValueError("Zero polycos found for table")
else:
# Reading from an old polycofile
pass
def tempo_polyco_table_reader(filename):
"""Read tempo style polyco file to an astropy table.
Tempo style: The polynomial ephemerides are written to file 'polyco.dat'. Entries
are listed sequentially within the file. The file format is::
==== ======= ============================================
Line Columns Item
==== ======= ============================================
1 1-10 Pulsar Name
11-19 Date (dd-mmm-yy)
20-31 UTC (hhmmss.ss)
32-51 TMID (MJD)
52-72 DM
74-79 Doppler shift due to earth motion (10^-4)
80-86 Log_10 of fit rms residual in periods
2 1-20 Reference Phase (RPHASE)
21-38 Reference rotation frequency (F0)
39-43 Observatory number
44-49 Data span (minutes)
50-54 Number of coefficients
55-75 Observing frequency (MHz)
76-80 Binary phase
3* 1-25 Coefficient 1 (COEFF(1))
26-50 Coefficient 2 (COEFF(2))
51-75 Coefficient 3 (COEFF(3))
==== ======= ============================================
* Subsequent lines have three coefficients each, up to NCOEFF
One polyco file could include more then one entrie
The pulse phase and frequency at time T are then calculated as::
DT = (T-TMID)*1440
PHASE = RPHASE + DT*60*F0 + COEFF(1) + DT*COEFF(2) + DT^2*COEFF(3) + ....
FREQ(Hz) = F0 + (1/60)*(COEFF(2) + 2*DT*COEFF(3) + 3*DT^2*COEFF(4) + ....)
Parameters
----------
filename : str
Name of the input poloco file.
References
----------
http://tempo.sourceforge.net/ref_man_sections/tz-polyco.txt
"""
f = open(filename, "r")
# Read entries to the end of file
entries = []
while True:
# Read first line
line1 = f.readline()
if len(line1) == 0:
break
fields = line1.split()
psrname = fields[0].strip()
date = fields[1].strip()
utc = fields[2]
tmid = np.longdouble(fields[3])
dm = float(fields[4])
doppler = float(fields[5])
logrms = float(fields[6])
# Read second line
line2 = f.readline()
fields = line2.split()
refPhaseInt, refPhaseFrac = fields[0].split(".")
refPhaseInt = data2longdouble(refPhaseInt)
refPhaseFrac = data2longdouble("." + refPhaseFrac)
if refPhaseInt < 0:
refPhaseFrac = -refPhaseFrac
refF0 = data2longdouble(fields[1])
obs = fields[2]
mjdSpan = data2longdouble(
fields[3]) / MIN_PER_DAY # Here change to constant
nCoeff = int(fields[4])
obsfreq = float(fields[5].strip())
try:
binaryPhase = data2longdouble(fields[6])
except ValueError:
binaryPhase = data2longdouble(0.0)
# Read coefficients
nCoeffLines = int(np.ceil(nCoeff / 3))
# if nCoeff%3>0:
# nCoeffLines += 1
coeffs = []
for i in range(nCoeffLines):
line = f.readline()
for c in line.split():
coeffs.append(data2longdouble(c))
coeffs = np.array(coeffs)
tmid = tmid * u.day
mjdspan = mjdSpan * u.day
tstart = data2longdouble(tmid) - data2longdouble(mjdspan) / 2.0
tstop = data2longdouble(tmid) + data2longdouble(mjdspan) / 2.0
rphase = Phase(refPhaseInt, refPhaseFrac)
refF0 = data2longdouble(refF0)
coeffs = data2longdouble(coeffs)
entry = PolycoEntry(tmid, mjdspan, refPhaseInt, refPhaseFrac, refF0,
nCoeff, coeffs, obs)
entries.append((
psrname,
date,
utc,
tmid.value,
dm,
doppler,
logrms,
binaryPhase,
mjdspan,
tstart,
tstop,
obs,
obsfreq,
entry,
))
entry_list = []
for ii in range(len(entries[0])):
entry_list.append([t[ii] for t in entries])
# Construct the polyco data table
pTable = table.Table(
entry_list,
names=(
"psr",
"date",
"utc",
"tmid",
"dm",
"doppler",
"logrms",
"binary_phase",
"mjd_span",
"t_start",
"t_stop",
"obs",
"obsfreq",
"entry",
),
meta={"name": "Polyco Data Table"},
)
pTable["index"] = np.arange(len(entries))
return pTable
def test_data2longdouble_converts_arrays(a):
assert_array_equal(data2longdouble(a), np.asarray(a, dtype=np.longdouble))
def test_data2longdouble_accepts_types(d, ld):
assert data2longdouble(d) == ld
