#!/usr/bin/env python
# -*- coding: utf-8 -*-
# Full license can be found in License.md
# ----------------------------------------------------------------------------
"""Hold, manipulate, and load the OCB and EAB data.
References
----------
.. [2] Angeline Burrell, Christer van der Meeren, & Karl M. Laundal. (2020).
aburrell/aacgmv2 (All Versions). Zenodo. doi:10.5281/zenodo.1212694.
.. [3] Shepherd, S. G. (2014), Altitude‐adjusted corrected geomagnetic
coordinates: Definition and functional approximations, Journal of
Geophysical Research: Space Physics, 119, 7501–7521,
doi:10.1002/2014JA020264.
"""
import datetime as dt
import numpy as np
import types
import warnings
import aacgmv2
from ocbpy import logger
import ocbpy.ocb_correction as ocbcor
from ocbpy import cycle_boundary
from ocbpy import ocb_time
from ocbpy.boundaries.files import get_default_file
from ocbpy.instruments import test_file
[docs]class OCBoundary(object):
"""Object containing open-closed field-line boundary (OCB) data.
Parameters
----------
filename : str or NoneType
File containing the required open-closed boundary data sorted by time.
If NoneType, no file is loaded. If 'default',
`ocbpy.boundaries.files.get_default_file` is called. (default='default')
instrument : str
Instrument providing the OCBoundaries. Requires 'image', 'ampere', or
'dmsp-ssj' if a file is provided. If using filename='default', also
accepts 'amp', 'si12', 'si13', 'wic', and ''. (default='')
hemisphere : int
Integer (+/- 1) denoting northern/southern hemisphere (default=1)
boundary_lat : float
Typical OCBoundary latitude in AACGM coordinates. Hemisphere will
give this boundary the desired sign. (default=74.0)
stime : dt.datetime or NoneType
First time to load data or beginning of file. If specifying time, be
sure to start before the time of the data to allow the best match within
the allowable time tolerance to be found. (default=None)
etime : dt.datetime or NoneType
Last time to load data or ending of file. If specifying time, be sure
to end after the last data point you wish to match to, to ensure the
best match within the allowable time tolerance is made. (default=None)
rfunc : numpy.ndarray, function, or NoneType
OCB radius correction function. If None, will use the instrument
default. Function must have AACGM MLT (in hours) as argument input.
To allow the boundary shape to change with univeral time, each temporal
instance may have a different function (array input). If a single
function is provided, will recast as an array that specifies this
function for all times. (default=None)
rfunc_kwargs : numpy.ndarray, dict, or NoneType
Optional keyword arguements for `rfunc`. If None is specified,
uses function defaults. If dict is specified, recasts as an array
of this dict for all times. Array must be an array of dicts.
(default=None)
Attributes
----------
records : int
Number of boundary records (default=0)
rec_ind : int
Current boundary record index (default=0; initialised=-1)
dtime : numpy.ndarray or NoneType
Numpy array of boundary datetimes (default=None)
phi_cent : numpy.ndarray or NoneType
Numpy array of floats that give the angle from AACGM midnight
of the boundary pole in degrees (default=None)
r_cent : numpy.ndarray or NoneType
Numpy array of floats that give the AACGM co-latitude of the boundary
pole in degrees (default=None)
r : numpy.ndarray or NoneType
Numpy array of floats that give the radius of the boundary in degrees
(default=None)
fom : numpy.ndarray or NoneType
Numpy array of floats that provides a figure of merit that can be used
to evaluate the quality of the boundary (default=None)
min_fom : float
Minimum acceptable figure of merit for data (default=-np.inf)
max_fom : float
Maximum acceptable figure of merit for data (default=np.inf)
x, y, etc. : numpy.ndarray or NoneType
Numpy array of floats that hold the remaining values held in `filename`
Methods
-------
inst_defaults
Get the instrument-specific boundary file loading information.
load
Load the data from the specified boundary file.
get_next_good_ocb_ind
Cycle to the the next quality boundary record.
normal_coord
Convert data position(s) to normalised co-ordinates relative to the OCB.
revert_coord
Convert the position of a measurement in OCB into AACGM co-ordinates.
get_aacgm_boundary_lat
Calculate the OCB latitude in AACGM coordinates at specified MLTs.
Raises
------
ValueError
Incorrect or incompatible input
"""
def __init__(self, filename="default", instrument='', hemisphere=1,
boundary_lat=74.0, stime=None, etime=None, rfunc=None,
rfunc_kwargs=None):
# Test the instrument input
if not hasattr(instrument, "lower"):
logger.error("OCB instrument must be a string [{:}]".format(
instrument))
self.filename = None
self.instrument = None
else:
self.instrument = instrument.lower()
# If a filename wanted and not provided, get one
if filename is None:
self.filename = None
elif not hasattr(filename, "lower"):
logger.warning("filename is not a string [{:}]".format(
filename))
self.filename = None
elif filename.lower() == "default":
self.filename, self.instrument = get_default_file(
stime, etime, hemisphere, self.instrument)
else:
self.filename = filename
# If a filename is available, make sure it is good
if self.filename is not None:
if not test_file(self.filename):
# If the filename is bad, return an uninitialized object
logger.warning("cannot open OCB file [{:s}]".format(
self.filename))
self.filename = None
# Test the hemisphere input
if hemisphere not in [1, -1]:
raise ValueError("hemisphere must be 1 (north) or -1 (south)")
# Set the default attribute values
self.hemisphere = hemisphere
self.records = 0
self.rec_ind = 0
self.dtime = None
self.phi_cent = None
self.r_cent = None
self.r = None
self.fom = None
self.rfunc = rfunc
self.rfunc_kwargs = rfunc_kwargs
self.min_fom = -np.inf
self.max_fom = np.inf
# Get the instrument defaults
hlines, ocb_cols, datetime_fmt = self.inst_defaults()
# Set the boundary latitude, if supplied
self.boundary_lat = 74.0 if boundary_lat is None else boundary_lat
# Ensure that the boundary is in the correct hemisphere
if np.sign(boundary_lat) != np.sign(hemisphere):
self.boundary_lat *= -1.0
# If possible, load the data. Any boundary correction is applied here.
if self.filename is not None:
if len(ocb_cols) > 0:
self.load(hlines=hlines, ocb_cols=ocb_cols,
datetime_fmt=datetime_fmt, stime=stime, etime=etime)
else:
self.load(stime=stime, etime=etime)
return
def __repr__(self):
"""Provide an evaluatable representation of the OCBoundary object."""
class_name = repr(self.__class__).split("'")[1]
# Get the start and end times
stime = None if self.dtime is None else self.dtime[0]
etime = None if self.dtime is None else self.dtime[-1]
# Format the function representations
if self.rfunc is None:
repr_rfunc = repr(self.rfunc)
else:
rfuncs = [".".join([ff.__module__, ff.__name__])
for ff in self.rfunc]
if len(set(rfuncs)) == 1:
repr_rfunc = rfuncs[0]
else:
repr_rfunc = 'numpy.array([{:s}], dtype=object)'.format(
', '.join(rfuncs))
# Format the function kwarg representations
if self.rfunc_kwargs is None:
repr_rfunc_kwargs = repr(self.rfunc_kwargs)
else:
rfuncs_kwargs = [repr(rkwarg) for rkwarg in self.rfunc_kwargs]
if len(set(rfuncs_kwargs)) == 1:
repr_rfunc_kwargs = rfuncs_kwargs[0]
else:
repr_rfunc_kwargs = 'numpy.array([{:s}], dtype=object)'.format(
', '.join(rfuncs_kwargs))
# Format the output
out = "".join([class_name, "(filename=", repr(self.filename),
", instrument=", repr(self.instrument),
", hemisphere={:d}, ".format(int(self.hemisphere)),
"boundary_lat={:f}, stime=".format(self.boundary_lat),
repr(stime), ", etime=", repr(etime), ", rfunc=",
repr_rfunc, ", rfunc_kwargs=", repr_rfunc_kwargs, ")"])
return out
def __str__(self):
"""Provide readable representation of the OCBoundary object."""
class_name = repr(self.__class__).split("'")[1].split(".")[-1]
if self.filename is None:
out = "No {:s} file specified\n".format(class_name)
else:
out = "{:s} file: {:s}\n".format(class_name, self.filename)
out = "{:s}Source instrument: ".format(out)
out = "{:s}{:s}\n".format(out, self.instrument.upper())
out = "{:s}Boundary reference latitude: ".format(out)
out = "{:s}{:.1f} degrees\n\n".format(out, self.boundary_lat)
if self.records == 0:
out = "{:s}No data loaded\n".format(out)
else:
out = "{:s}{:d} records from {:}".format(out, self.records,
self.dtime[0])
out = "{:s} to {:}\n\n".format(out, self.dtime[-1])
if self.records == 1:
irep = [0]
else:
irep = np.unique(
np.arange(0, self.records, 1)[[0, 1, -2, -1]])
head = "YYYY-MM-DD HH:MM:SS Phi_Centre R_Centre R"
out = "{:s}{:s}\n{:-<77s}\n".format(out, head, "")
for i in irep:
out = "{:s}{:} {:.2f}".format(out, self.dtime[i],
self.phi_cent[i])
out = "{:s} {:.2f} {:.2f}\n".format(out, self.r_cent[i],
self.r[i])
# Determine which scaling functions are used
if self.rfunc is not None:
out = "{:s}\nUses scaling function(s):\n".format(out)
fnames = list(set([".".join([ff.__module__, ff.__name__])
for ff in self.rfunc]))
for ff in fnames:
kw = list(set([self.rfunc_kwargs[i].__str__()
for i, rf in enumerate(self.rfunc)
if rf.__name__ == ff.split(".")[-1]]))
for kk in kw:
out = "{:s}{:s}(**{:s})\n".format(out, ff, kk)
return out
[docs] def inst_defaults(self):
"""Get the instrument-specific OCB file loading information.
Returns
-------
hlines : int
Number of header lines
ocb_cols : str
String containing the names for each data column
datetime_fmt : str
String containing the datetime format
Notes
-----
Updates the min_fom attribute for AMPERE and DMSP-SSJ
"""
if self.instrument == "image":
hlines = 0
ocb_cols = "year soy num_sectors phi_cent r_cent r a r_err fom"
datetime_fmt = ""
self.max_fom = 5.0 # From Chisham et al. (in prep)
elif self.instrument == "ampere":
hlines = 0
ocb_cols = "date time r x y fom"
datetime_fmt = "%Y%m%d %H:%M"
self.min_fom = 0.15 # From Milan et al. (2015)
elif self.instrument == "dmsp-ssj":
hlines = 1
ocb_cols = "sc date time r x y fom x_1 y_1 x_2 y_2"
datetime_fmt = "%Y-%m-%d %H:%M:%S"
self.min_fom = 3.0 # From Burrell et al. (2019)
else:
hlines = 0
ocb_cols = ""
datetime_fmt = ""
return hlines, ocb_cols, datetime_fmt
[docs] def load(self, hlines=0,
ocb_cols="year soy num_sectors phi_cent r_cent r a r_err fom",
datetime_fmt="", stime=None, etime=None):
"""Load the data from the specified boundary file.
Parameters
----------
ocb_cols : str
String specifying format of OCB file. All but the first two
columns must be included in the string, additional data values will
be ignored. If 'year soy' aren't used, expects
'date time' in 'YYYY-MM-DD HH:MM:SS' format.
(default='year soy num_sectors phi_cent r_cent r a r_err r_merit')
hlines : int
Number of header lines preceeding data in the OCB file (default=0)
datetime_fmt : str
A string used to read in 'date time' data. Not used if 'year soy'
is specified. (default='')
stime : dt.datetime or NoneType
Time to start loading data or None to start at beginning of file.
(default=None)
etime : datetime or NoneType
Time to stop loading data or None to end at the end of the file.
(default=None)
"""
cols = ocb_cols.split()
dflag = -1
ldtype = [(k, float) if k != "num_sectors" else (k, int) for k in cols]
if "soy" in cols and "year" in cols:
dflag = 0
ldtype[cols.index('year')] = ('year', int)
elif "date" in cols and "time" in cols:
dflag = 1
ldtype[cols.index('date')] = ('date', '|U50')
ldtype[cols.index('time')] = ('time', '|U50')
if dflag < 0:
logger.error("missing time columns in [{:s}]".format(ocb_cols))
return
# Read the OCB data
odata = np.rec.array(np.genfromtxt(self.filename, skip_header=hlines,
dtype=ldtype))
oname = list(odata.dtype.names)
# Load the data into the OCBoundary object
#
# Start by getting the time and location in the desired format
self.rec_ind = -1
dt_list = list()
if stime is None and etime is None:
itime = np.arange(0, odata.shape[0], 1)
else:
itime = list()
for i in range(odata.shape[0]):
year = odata.year[i] if dflag == 0 else None
soy = odata.soy[i] if dflag == 0 else None
date = None if dflag == 0 else odata.date[i]
tod = None if dflag == 0 else odata.time[i]
dtime = ocb_time.convert_time(year=year, soy=soy, date=date,
tod=tod, datetime_fmt=datetime_fmt)
if stime is None and etime is None:
dt_list.append(dtime)
elif((stime is None or stime <= dtime)
and (etime is None or etime >= dtime)):
dt_list.append(dtime)
itime.append(i)
if hasattr(odata, 'x') and hasattr(odata, 'y'):
# Location is given by x-y coordinates where the origin lies
# on the magnetic pole, the x-axis follows the dusk-dawn
# meridian (positive towards dawn), and the y-axis follows the
# midnight-noon meridian (positive towards noon)
# Calculate the polar coordinates from the x-y coordinates
odata.r_cent = np.sqrt(odata.x**2 + odata.y**2)
oname.append("r_cent")
# phi_cent is zero at magnetic midnight rather than dawn, so we
# need to add 90.0 degrees from the arctangent. Then convert all
# degrees to their positive angles.
odata.phi_cent = np.degrees(np.arctan2(odata.y, odata.x)) + 90.0
odata.phi_cent[odata.phi_cent < 0.0] += 360.0
oname.append("phi_cent")
# Load the required information not contained in odata
self.records = len(dt_list)
self.dtime = np.array(dt_list)
# Set the boundary function
if self.rfunc is None:
self._set_default_rfunc()
elif isinstance(self.rfunc, types.FunctionType):
self.rfunc = np.full(shape=self.records, fill_value=self.rfunc)
elif hasattr(self.rfunc, "shape"):
if self.rfunc.shape != self.dtime.shape:
raise ValueError("Misshaped correction function array")
else:
raise ValueError("Unknown input type for correction function")
# Set the boundary function keyword inputs
if self.rfunc_kwargs is None:
self.rfunc_kwargs = np.full(shape=self.records, fill_value={})
elif isinstance(self.rfunc_kwargs, dict):
self.rfunc_kwargs = np.full(shape=self.records,
fill_value=self.rfunc_kwargs)
elif hasattr(self.rfunc_kwargs, "shape"):
if self.rfunc_kwargs.shape != self.dtime.shape:
raise ValueError("Misshaped correction function keyword array")
else:
raise ValueError("Unknown input type for correction keywords")
# Load the attributes saved in odata
for nn in oname:
setattr(self, nn, getattr(odata, nn)[itime])
return
[docs] def get_next_good_ocb_ind(self, min_merit=None, max_merit=None, **kwargs):
"""Cycle to the the next quality OCB record.
Parameters
----------
min_merit : float or NoneType
Minimum value for the default figure of merit or None to not
apply a custom minimum (default=None)
max_merit : float or NoneTye
Maximum value for the default figure of merit or None to not apply
a custom maximum (default=None)
min_sectors : int
Minimum number of MLT sectors required for good OCB. Deprecated,
will be removed in version 0.3.1+ (default=7)
rcent_dev : float
Maximum number of degrees between the new centre and the AACGM pole
Deprecated, will be removed in version 0.3.1+ (default=8.0)
max_r : float
Maximum radius for open-closed field line boundary in degrees.
Deprecated, will be removed in version 0.3.1+ (default=23.0)
min_r : float
Minimum radius for open-closed field line boundary in degrees
Deprecated, will be removed in version 0.3.1+ (default=10.0)
kwargs : dict
Dict with optional selection criteria. The key should correspond
to a data attribute and the value must be a tuple with the first
value specifying 'max', 'min', 'maxeq', 'mineq', or 'equal' and the
second value specifying the value to use in the comparison.
Notes
-----
Updates self.rec_ind to the index of next good OCB record or a value
greater than self.records if there aren't any more good records
available after the starting point
Deprecated IMAGE FUV checks that:
- more than 6 MLT boundary values have contributed to OCB circle
- the OCB 'pole' is with 8 degrees of the AACGM pole
- the OCB 'radius' is greater than 10 and less than 23 degrees
AMPERE/DMSP-SSJ and new IMAGE FUV checks that:
- the Figure of Merit is greater than or equal to the specified minimum
(`min_fom`) or less than or equal to the specified maximum (`max_fom`)
"""
# Add check for deprecated and custom kwargs
dep_comp = {'min_sectors': ['num_sectors', ('mineq', 7)],
'rcent_dev': ['r_cent', ('maxeq', 8.0)],
'max_r': ['r', ('maxeq', 23.0)],
'min_r': ['r', ('mineq', 10.0)]}
cust_keys = list(kwargs.keys())
for ckey in cust_keys:
if ckey in dep_comp.keys():
warnings.warn("".join(["Deprecated kwarg will be removed in ",
"version 0.3.1+. To replecate behaviour",
", use {", dep_comp[ckey][0], ": ",
repr(dep_comp[ckey][1]), "}"]),
DeprecationWarning, stacklevel=2)
del kwargs[ckey]
if hasattr(self, dep_comp[ckey][0]):
kwargs[dep_comp[ckey][0]] = dep_comp[ckey][1]
else:
if not hasattr(self, ckey):
logger.warning(
"Removing unknown selection attribute {:}".format(ckey))
del kwargs[ckey]
# Adjust the FoM determination for custom inputs
if min_merit is None:
min_merit = self.min_fom
if max_merit is None:
max_merit = self.max_fom
# Incriment forward from previous boundary
self.rec_ind += 1
while self.rec_ind < self.records:
# Evaluate the current boundary for quality, using optional
# parameters
good = True
for ckey in kwargs.keys():
test_val = getattr(self, ckey)[self.rec_ind]
if kwargs[ckey][0] == "min" and test_val <= kwargs[ckey][1]:
good = False
break
elif kwargs[ckey][0] == "mineq" and test_val < kwargs[ckey][1]:
good = False
break
elif kwargs[ckey][0] == "equal" and test_val != kwargs[ckey][1]:
good = False
break
elif kwargs[ckey][0] == "maxeq" and test_val > kwargs[ckey][1]:
good = False
break
elif kwargs[ckey][0] == "max" and test_val >= kwargs[ckey][1]:
good = False
break
# Evaluate the current boundary for quality, using non-optional
# parameters
if good:
test_val = self.fom[self.rec_ind]
if test_val >= min_merit and test_val <= max_merit:
return
# Cycle to next boundary
self.rec_ind += 1
return
[docs] def normal_coord(self, lat, lt, coords='magnetic', height=350.0,
method='ALLOWTRACE'):
"""Convert position(s) to normalised co-ordinates relative to the OCB.
Parameters
----------
lat : float or array-like
Input latitude (degrees), must be geographic, geodetic, or AACGMV2
lt : float or array-like
Input local time (hours), must be solar or AACGMV2 magnetic
coords : str
Input coordiate system. Accepts 'magnetic', 'geocentric', or
'geodetic' (default='magnetic')
height : float or array-like
Height (km) at which AACGMV2 coordinates will be calculated, if
geographic coordinates are provided (default=350.0)
method : str
String denoting which type(s) of conversion to perform, if
geographic coordinates are provided. Expects either 'TRACE' or
'ALLOWTRACE'. See AACGMV2 for details [2]_. (default='ALLOWTRACE')
Returns
-------
ocb_lat : float or array-like
Magnetic latitude relative to OCB (degrees)
ocb_mlt : float or array-like
Magnetic local time relative to OCB (hours)
r_corr : float or array-like
Radius correction to OCB (degrees)
Notes
-----
Approximation - Conversion assumes a planar surface
See Also
--------
aacgmv2
"""
# Cast input as arrays
lat = np.asarray(lat)
lt = np.asarray(lt)
height = np.asarray(height)
# Initialize output
out_shape = max([lat.shape, lt.shape, height.shape])
ocb_lat = np.full(shape=out_shape, fill_value=np.nan)
ocb_mlt = np.full(shape=out_shape, fill_value=np.nan)
r_corr = np.full(shape=out_shape, fill_value=np.nan)
# Test the OCB record index
if self.rec_ind < 0 or self.rec_ind >= self.records:
return ocb_lat, ocb_mlt, r_corr
# If needed, convert from geographic to magnetic coordinates
if coords.lower().find('mag') < 0:
# Convert from lt to longitude
lon = ocb_time.slt2glon(lt, self.dtime[self.rec_ind])
# If geocentric coordinates are specified, add this info to the
# method flag
if coords.lower() == 'geocentric':
method = "|".join([method, coords.upper()])
aacgm_lat, _, aacgm_mlt = aacgmv2.get_aacgm_coord_arr(
lat, lon, height, self.dtime[self.rec_ind], method)
else:
aacgm_lat = lat
aacgm_mlt = lt
# Ensure the correct hemisphere is loaded for this data
if np.any(np.sign(aacgm_lat) != self.hemisphere):
if np.all(np.sign(aacgm_lat) != self.hemisphere):
return ocb_lat, ocb_mlt, r_corr
aacgm_lat[np.sign(aacgm_lat) != self.hemisphere] = np.nan
# Calculate the center of the OCB
phi_cent_rad = np.radians(self.phi_cent[self.rec_ind])
xc = self.r_cent[self.rec_ind] * np.cos(phi_cent_rad)
yc = self.r_cent[self.rec_ind] * np.sin(phi_cent_rad)
# Calculate the desired point location relative to the AACGM pole
scalep = 90.0 - self.hemisphere * aacgm_lat
xp = scalep * np.cos(ocb_time.hr2rad(aacgm_mlt))
yp = scalep * np.sin(ocb_time.hr2rad(aacgm_mlt))
# Get the distance between the OCB pole and the point location. This
# distance is then scaled by r, the OCB radius. For non-circular
# boundaries, r is a function of MLT
r_corr = self.rfunc[self.rec_ind](aacgm_mlt,
**self.rfunc_kwargs[self.rec_ind])
scalen = (90.0 - abs(self.boundary_lat)) / (self.r[self.rec_ind]
+ r_corr)
xn = (xp - xc) * scalen
yn = (yp - yc) * scalen
ocb_lat = self.hemisphere * (90.0 - np.sqrt(xn**2 + yn**2))
ocb_mlt = ocb_time.deg2hr(np.degrees(np.arctan2(yn, xn)))
ocb_mlt = ocb_time.fix_range(ocb_mlt, 0.0, 24.0)
return ocb_lat, ocb_mlt, r_corr
[docs] def revert_coord(self, ocb_lat, ocb_mlt, r_corr=0.0, coords='magnetic',
height=350.0, method='ALLOWTRACE'):
"""Convert the position of a measurement in OCB into AACGM co-ordinates.
Parameters
----------
ocb_lat : float or array-like
Input OCB latitude in degrees
ocb_mlt : float or array-like
Input OCB local time in hours
r_corr : float or array-like
Input OCB radial correction in degrees, may be a function of
AACGM MLT (default=0.0)
coords : str
Output coordiate system. Accepts 'magnetic', 'geocentric', or
'geodetic' (default='magnetic')
height : float or array-like
Geocentric height above sea level (km) at which AACGMV2 coordinates
will be calculated, if geographic coordinates are desired
(default=350.0)
method : str
String denoting which type(s) of conversion to perform, if
geographic coordinates are provided. Expects either 'TRACE' or
'ALLOWTRACE'. See AACGMV2 for details [2]_. (default='ALLOWTRACE')
Returns
-------
lat : float or array-like
latitude (degrees)
lt : float or array-like
local time (hours)
Notes
-----
Approximation - Conversion assumes a planar surface
See Also
--------
aacgmv2
"""
# Cast input as arrays
ocb_lat = np.asarray(ocb_lat)
ocb_mlt = np.asarray(ocb_mlt)
r_corr = np.asarray(r_corr)
height = np.asarray(height)
# Initialize output
out_shape = max([ocb_lat.shape, ocb_mlt.shape, r_corr.shape,
height.shape])
lat = np.full(shape=out_shape, fill_value=np.nan)
lt = np.full(shape=out_shape, fill_value=np.nan)
# Test the OCB index and hemisphere
if self.rec_ind < 0 or self.rec_ind >= self.records:
return lat, lt
if np.all(np.sign(ocb_lat) != self.hemisphere):
return lat, lt
# Perform the coordinate transformation
phi_cent_rad = np.radians(self.phi_cent[self.rec_ind])
xc = self.r_cent[self.rec_ind] * np.cos(phi_cent_rad)
yc = self.r_cent[self.rec_ind] * np.sin(phi_cent_rad)
rn = 90.0 - self.hemisphere * ocb_lat
thetan = ocb_mlt * np.pi / 12.0
xn = rn * np.cos(thetan)
yn = rn * np.sin(thetan)
scale_ocb = (self.r[self.rec_ind]
+ r_corr) / (90.0 - self.hemisphere * self.boundary_lat)
xp = xn * scale_ocb + xc
yp = yn * scale_ocb + yc
aacgm_lat = self.hemisphere * (90.0 - np.sqrt(xp**2 + yp**2))
aacgm_mlt = ocb_time.deg2hr(np.degrees(np.arctan2(yp, xp)))
aacgm_mlt = ocb_time.fix_range(aacgm_mlt, 0.0, 24.0)
# If needed, convert from magnetic to geographic coordinates
if coords.lower().find('mag') < 0:
# Convert from mlt to longitude
lon = aacgmv2.convert_mlt(aacgm_mlt, self.dtime[self.rec_ind],
m2a=True)
# If geocentric coordinates are specified, add this info to the
# method flag
if coords.lower() == 'geocentric':
method = "|".join([method, coords.upper()])
method = "|".join([method, "A2G"])
lat, lon, _ = aacgmv2.convert_latlon_arr(aacgm_lat, lon, height,
self.dtime[self.rec_ind],
method)
# Convert from longitude to solar local time
lt = ocb_time.glon2slt(lon, self.dtime[self.rec_ind])
else:
lat = aacgm_lat
lt = aacgm_mlt
return lat, lt
[docs] def get_aacgm_boundary_lat(self, aacgm_mlt, rec_ind=None,
overwrite=False, set_lon=True):
"""Calculate the OCB latitude in AACGM coordinates at specified MLTs.
Parameters
----------
aacgm_mlt : int, float, or array-like
AACGM longitude location(s) (in degrees) for which the OCB latitude
will be calculated.
rec_ind : int, array-like, or NoneType
Record index for which the OCB AACGM latitude will be calculated,
or None to calculate all boundary locations (default=None).
overwrite : bool
Overwrite previous boundary locations if this time already has
calculated boundary latitudes for a different set of input
longitudes (default=False).
set_lon : bool
Calculate the AACGM longitude of the OCB alongside the MLT
(default=True).
Notes
-----
Updates OCBoundary object with list attributes. If no boundary value
is calculated at a certain time, the list is padded with None. If
a boundary latitude cannot be calculated at that time and longitude,
that time and longitude is filled with NaN.
`aacgm_boundary_lat` contains the AACGM latitude location(s) of the OCB
(in degrees) for each requested time [3]_.
`aacgm_boundary_mlt` holds the aacgm_mlt input for each requested
time. The requested MLT may differ from time to time, to allow
easy comparison with satellite passes [3]_.
`aacgm_boundary_lon` holds the aacgm_lon input for each requested
time. This is calculated from `aacgm_boundary_mlt` by default [3]_.
If the boundary radius is not defined at all MLT (possible for
poorly constrained boundaries), then MLT with multiple boundary values
will only return one possible solution.
"""
# Ensure the boundary longitudes span from 0-360 degrees
aacgm_mlt = np.asarray(aacgm_mlt)
aacgm_mlt[aacgm_mlt < 0.0] += 24.0
aacgm_mlt[aacgm_mlt >= 24.0] -= 24.0
if not hasattr(self, 'aacgm_boundary_mlt'):
self.aacgm_boundary_mlt = [None for i in range(self.records)]
if not hasattr(self, 'aacgm_boundary_lat'):
self.aacgm_boundary_lat = [None for i in range(self.records)]
if set_lon and not hasattr(self, 'aacgm_boundary_lon'):
self.aacgm_boundary_lon = [None for i in range(self.records)]
# Get the indices to calculate the boundary latitudes
if rec_ind is None:
# Create array of all indices
rinds = np.arange(0, self.records, 1)
else:
# Create array of indices as integers
rinds = np.asarray(rec_ind).astype('int')
# Ensure single values are stored as an interable object
if len(rinds.shape) == 0:
rinds = rinds.reshape(1,)
# Calculate the boundary location for each requested time
for i in rinds:
# If data exists here and the overwrite option is off, skip
if self.aacgm_boundary_lat[i] is None or overwrite:
# Calculate the difference between the output MLT and the
# MLT of the centre of the polar cap, which is give in degrees
del_mlt = ocb_time.hr2rad(aacgm_mlt
- ocb_time.deg2hr(self.phi_cent[i]))
# Calculate the radius of the OCB in degrees
r_corr = self.rfunc[i](aacgm_mlt, **self.rfunc_kwargs[i])
scale_r = self.r[i] + r_corr
rad = self.r_cent[i] * np.cos(del_mlt) \
+ np.sqrt(scale_r**2 - (self.r_cent[i]
* np.sin(del_mlt))**2)
# If the radius is negative, set to NaN
if len(rad.shape) > 0:
rad[rad < 0.0] = np.nan
else:
rad = np.nan if rad < 0.0 else float(rad)
# Calculate the latitude of the OCB in AACGM coordinates
self.aacgm_boundary_lat[i] = self.hemisphere * (90.0 - rad)
# Save the MLT at this time
self.aacgm_boundary_mlt[i] = aacgm_mlt
# Set the longitude at this time
if set_lon:
self.aacgm_boundary_lon[i] = np.asarray(
aacgmv2.convert_mlt(aacgm_mlt, self.dtime[i],
m2a=True))
else:
logger.warning("".join(["unable to update AACGM boundary ",
"latitude at {:}".format(self.dtime[i]),
", overwrite blocked"]))
return
def _set_default_rfunc(self):
"""Set the default instrument OCB boundary function.
Notes
-----
Assign a function for each time in case we have a data set with a
correction that changes with UT
"""
if self.instrument in ["image", "dmsp-ssj"]:
self.rfunc = np.full(shape=self.records,
fill_value=ocbcor.circular)
elif self.instrument == "ampere":
self.rfunc = np.full(shape=self.records,
fill_value=ocbcor.elliptical)
else:
raise ValueError("unknown instrument")
return
[docs]class EABoundary(OCBoundary):
"""Object containing equatorward auroral boundary (EAB) data.
Parameters
----------
filename : str or NoneType
File containing the required equatorward auroral boundary data sorted by
time. If NoneType, no file is loaded. If 'default',
`ocbpy.boundaries.files.get_default_file` is called. (default='default')
instrument : str
Instrument providing the EABoundaries. Requires 'image' or 'dmsp-ssj'
if a file is provided. If using filename='default', also accepts
'si12', 'si13', 'wic', and ''. (default='')
hemisphere : int
Integer (+/- 1) denoting northern/southern hemisphere (default=1)
boundary_lat : float
Typical EABoundary latitude in AACGM coordinates. Hemisphere will
give this boundary the desired sign. (default=64.0)
stime : dt.datetime or NoneType
First time to load data or beginning of file. If specifying time, be
sure to start before the time of the data to allow the best match within
the allowable time tolerance to be found. (default=None)
etime : dt.datetime or NoneType
Last time to load data or ending of file. If specifying time, be sure
to end after the last data point you wish to match to, to ensure the
best match within the allowable time tolerance is made. (default=None)
rfunc : numpy.ndarray, function, or NoneType
EAB radius correction function. If None, will use the instrument
default. Function must have AACGM MLT (in hours) as argument input.
To allow the boundary shape to change with univeral time, each temporal
instance may have a different function (array input). If a single
function is provided, will recast as an array that specifies this
function for all times. (default=None)
rfunc_kwargs : numpy.ndarray, dict, or NoneType
Optional keyword arguements for `rfunc`. If None is specified,
uses function defaults. If dict is specified, recasts as an array
of this dict for all times. Array must be an array of dicts.
(default=None)
See Also
--------
ocbpy.OCBoundary
Raises
------
ValueError
Incorrect or incompatible input
"""
def __init__(self, filename="default", instrument='', hemisphere=1,
boundary_lat=64.0, stime=None, etime=None, rfunc=None,
rfunc_kwargs=None):
# Process the defaults that differ for the EAB
if rfunc is None:
# Set to a function that will not alter the data
self._set_default_rfunc(instrument)
rfunc = self.rfunc
self.rfunc = None
if(hasattr(filename, "lower") and hasattr(instrument, "lower")
and filename.lower() == "default"):
filename, instrument = get_default_file(stime, etime, hemisphere,
instrument, bound='eab')
# Initialize the class
OCBoundary.__init__(self, filename=filename, instrument=instrument,
hemisphere=hemisphere, boundary_lat=boundary_lat,
stime=stime, etime=etime, rfunc=rfunc,
rfunc_kwargs=rfunc_kwargs)
return
def _set_default_rfunc(self, input_instrument):
"""Set the default instrument EAB boundary function.
Parameters
----------
input_instrument : str
Input instrument name
Notes
-----
Assign a function for each time in case we have a data set with a
correction that changes with UT
"""
if input_instrument in ["", "default", "image", "dmsp-ssj"]:
self.rfunc = ocbcor.circular
elif not hasattr(input_instrument, "lower"):
# Allow an empty class object to be initialised
self.rfunc = None
else:
# Only raise an error if the input instrument is a string
raise ValueError("unknown instrument")
return
[docs]class DualBoundary(object):
"""Object containing EAB and OCB data for dual-boundary coordinates.
Parameters
----------
eab_filename : str or NoneType
File containing the required equatorward auroral boundary data sorted by
time. If NoneType, no file is loaded. If 'default',
`ocbpy.boundaries.files.get_default_file` is called. (default='default')
ocb_filename : str or NoneType
File containing the required open-closed field line boundary data sorted
by time. If NoneType, no file is loaded. If 'default',
`ocbpy.boundaries.files.get_default_file` is called. (default='default')
eab_instrument : str
Instrument providing the EABoundaries. Requires 'image' or 'dmsp-ssj'
if a file is provided. If using filename='default', also accepts
'si12', 'si13', 'wic', and ''. (default='')
ocb_instrument : str
Instrument providing the OCBoundaries. Requires 'image', 'ampere, or
'dmsp-ssj' if a file is provided. If using filename='default', also
accepts 'si12', 'si13', 'wic', and ''. (default='')
hemisphere : int
Integer (+/- 1) denoting northern/southern hemisphere (default=1)
eab_lat : float
Typical EABoundary latitude in AACGM coordinates. Hemisphere will
give this boundary the desired sign. (default=64.0)
ocb_lat : float
Typical OCBoundary latitude in AACGM coordinates. Hemisphere will
give this boundary the desired sign. (default=74.0)
stime : dt.datetime or NoneType
First time to load data or beginning of file. If specifying time, be
sure to start before the time of the data to allow the best match within
the allowable time tolerance to be found. (default=None)
etime : dt.datetime or NoneType
Last time to load data or ending of file. If specifying time, be sure
to end after the last data point you wish to match to, to ensure the
best match within the allowable time tolerance is made. (default=None)
eab_rfunc : numpy.ndarray, function, or NoneType
EAB radius correction function. If None, will use the instrument
default. Function must have AACGM MLT (in hours) as argument input.
To allow the boundary shape to change with univeral time, each temporal
instance may have a different function (array input). If a single
function is provided, will recast as an array that specifies this
function for all times. (default=None)
eab_rfunc_kwargs : numpy.ndarray, dict, or NoneType
Optional keyword arguements for `eab_rfunc`. If None is specified,
uses function defaults. If dict is specified, recasts as an array
of this dict for all times. Array must be an array of dicts.
(default=None)
ocb_rfunc : numpy.ndarray, function, or NoneType
OCB radius correction function. If None, will use the instrument
default. Function must have AACGM MLT (in hours) as argument input.
To allow the boundary shape to change with univeral time, each temporal
instance may have a different function (array input). If a single
function is provided, will recast as an array that specifies this
function for all times. (default=None)
ocb_rfunc_kwargs : numpy.ndarray, dict, or NoneType
Optional keyword arguements for `ocb_rfunc`. If None is specified,
uses function defaults. If dict is specified, recasts as an array
of this dict for all times. Array must be an array of dicts.
(default=None)
eab : ocbpy.EABoundary or NoneType
Equatorward auroral boundary data object or None to initialize here
(default=None)
ocb : ocbpy.OCBoundary
Open-closed field line boundary data oject or Noneto initialize here
(default=None)
max_delta : int
Maximum number of seconds allowed between paired EAB and OCB records
(default=60)
Attributes
----------
eab
ocb
max_delta
hemisphere
dtime : numpy.ndarray
Numpy array of paired boundary datetimes
eab_ind : numpy.ndarray
Numpy array of EAB indices for a good quality paired boundary
ocb_ind : numpy.ndarray
Numpy array of OCB indices for a good quality paired boundary
rec_ind : int
Current OCB record index (default=0; initialised=-1)
records : int
Maximum number of paired boundary records
Methods
-------
set_good_ind
Pair the good indices for the quality EABs and OCBs.
get_next_good_ind
Cycle to the the next quality paired boundary record.
normal_coord
Convert data position(s) to normalised co-ordinates relative to the OCB.
revert_coord
Convert the position of a measurement in OCB into AACGM co-ordinates.
get_aacgm_boundary_lats
Calculate the EAB and OCB latitude in AACGM coordinates.
calc_r
Calculate the scaled and unscaled radius at a normalised co-ordinates.
Raises
------
ValueError
Incorrect or incompatible input, mismatched hemisphere assignment
"""
def __init__(self, eab_filename="default", ocb_filename="default",
eab_instrument='', ocb_instrument='', hemisphere=1,
eab_lat=64.0, ocb_lat=74.0, stime=None, etime=None,
eab_rfunc=None, eab_rfunc_kwargs=None, ocb_rfunc=None,
ocb_rfunc_kwargs=None, eab=None, ocb=None, max_delta=60):
# Ensure the boundary latitudes are realistic
if abs(eab_lat) >= abs(ocb_lat):
raise ValueError('OCB must be poleward of the EAB')
if max_delta <= 0:
raise ValueError(''.join(['Maximum time difference between ',
'boundary measurements must be positive',
' or zero']))
# Initalize the subclass attributes
if eab is None:
self.eab = EABoundary(filename=eab_filename,
instrument=eab_instrument,
hemisphere=hemisphere, boundary_lat=eab_lat,
stime=stime, etime=etime, rfunc=eab_rfunc,
rfunc_kwargs=eab_rfunc_kwargs)
else:
self.eab = eab
if ocb is None:
self.ocb = OCBoundary(filename=ocb_filename,
instrument=ocb_instrument,
hemisphere=hemisphere, boundary_lat=ocb_lat,
stime=stime, etime=etime, rfunc=ocb_rfunc,
rfunc_kwargs=ocb_rfunc_kwargs)
else:
self.ocb = ocb
# Set the hemisphere
self.hemisphere = self.ocb.hemisphere
if self.hemisphere != self.eab.hemisphere:
raise ValueError('mismatched hemisphere assignment')
# Create a time index, saving indices where both boundaries are good
self.max_delta = max_delta
self.set_good_ind()
return
def __repr__(self):
out_str = "".join([repr(self.__class__).split("'")[1], "(eab=",
repr(self.eab), ", ocb=", repr(self.ocb),
", max_delta=", repr(self.max_delta), ")"])
return out_str
def __str__(self):
out = "Dual Boundary data\n{:d} good boundary ".format(self.records)
if self.records == 0:
out = "{:s}pairs\nMaximum ".format(out)
else:
out = "{:s}pairs from {:} to {:}\nMaximum ".format(
out, self.dtime[0], self.dtime[-1])
out = "{:s} boundary difference of {:.1f} s".format(out, self.max_delta)
out = "{:s}\n\n{:s}\n{:s}\n".format(out, self.eab.__str__(),
self.ocb.__str__())
return out
def _get_current_aacgm_boundary(self):
"""Get the current AACGM boundaries for the EAB and OCB classes.
Returns
-------
eab_blat : array-like or NoneType
EAB boundary latitude in AACGM coordinates at the record index,
None of no boundary is set.
eab_bmlt : array-like or NoneType
EAB boundary MLT in AACGM coordinates at the record index,
None of no boundary is set.
ocb_blat : array-like or NoneType
OCB boundary latitude in AACGM coordinates at the record index,
None of no boundary is set.
ocb_bmlt : array-like or NoneType
OCB boundary MLT in AACGM coordinates at the record index,
None of no boundary is set.
"""
# Set the OCB output
if hasattr(self.ocb, "aacgm_boundary_lat"):
ocb_blat = self.ocb.aacgm_boundary_lat[self.ocb.rec_ind]
ocb_bmlt = self.ocb.aacgm_boundary_mlt[self.ocb.rec_ind]
else:
ocb_blat = None
ocb_bmlt = None
# Set the EAB output
if hasattr(self.eab, "aacgm_boundary_lat"):
eab_blat = self.eab.aacgm_boundary_lat[self.eab.rec_ind]
eab_bmlt = self.eab.aacgm_boundary_mlt[self.eab.rec_ind]
else:
eab_blat = None
eab_bmlt = None
return eab_blat, eab_bmlt, ocb_blat, ocb_bmlt
@property
def rec_ind(self):
"""Record index that identifies the current good EAB/OCB pair."""
return self._rec_ind
@rec_ind.setter
def rec_ind(self, rec_ind):
# Set the record index, and cycle the sub-class boundary indices
self._rec_ind = rec_ind
if rec_ind < 0:
self.ocb.rec_ind = rec_ind
self.eab.rec_ind = rec_ind
elif rec_ind >= self.records:
del_ind = self.records - rec_ind
self.ocb.rec_ind = self.ocb.records + del_ind
self.eab.rec_ind = self.eab.records + del_ind
else:
self.ocb.rec_ind = self.ocb_ind[rec_ind]
self.eab.rec_ind = self.eab_ind[rec_ind]
return
[docs] def set_good_ind(self, ocb_min_merit=None, ocb_max_merit=None,
ocb_kwargs=None, eab_min_merit=None, eab_max_merit=None,
eab_kwargs=None):
"""Pair the good indices for the quality EABs and OCBs.
Parameters
----------
ocb_min_merit : float or NoneType
Minimum value for the default figure of merit or None to not apply
a custom minimum (default=None)
ocb_max_merit : float or NoneTye
Maximum value for the default figure of merit or None to not apply
a custom maximum (default=None)
ocb_kwargs : dict or NoneType
Dict with optional selection criteria. The key should correspond
to a data attribute and the value must be a tuple with the first
value specifying 'max', 'min', 'maxeq', 'mineq', or 'equal' and the
second value specifying the value to use in the comparison.
None provides no optional selection criteria. (default=None)
eab_min_merit : float or NoneType
Minimum value for the default figure of merit or None to not apply
a custom minimum (default=None)
eab_max_merit : float or NoneTye
Maximum value for the default figure of merit or None to not apply
a custom maximum (default=None)
eab_kwargs : dict or NoneType
Dict with optional selection criteria. The key should correspond
to a data attribute and the value must be a tuple with the first
value specifying 'max', 'min', 'maxeq', 'mineq', or 'equal' and the
second value specifying the value to use in the comparison.
None provides no optional selection criteria. (default=None)
"""
# Initalize the class attributes
if self.ocb.dtime is None or self.eab.dtime is None:
self.records = 0
self.dtime = None
self.ocb_ind = None
self.eab_ind = None
return
self.dtime = list()
self.ocb_ind = list()
self.eab_ind = list()
# Save the current EAB record index
icurrent = self.eab.rec_ind
self.eab.rec_ind = -1
# Get the good OCB indices
if ocb_kwargs is None:
ocb_kwargs = {}
ocb_kwargs['min_merit'] = ocb_min_merit
ocb_kwargs['max_merit'] = ocb_max_merit
good_ocb = cycle_boundary.retrieve_all_good_indices(self.ocb,
**ocb_kwargs)
# Initialize the EAB good index selection options
if eab_kwargs is None:
eab_kwargs = {}
eab_kwargs['min_merit'] = eab_min_merit
eab_kwargs['max_merit'] = eab_max_merit
# Match the EABs with the good OCB times
iocb = 0
while self.eab.rec_ind < self.eab.records and iocb is not None:
# Cycle the OCB record index to match the next good EAB index
iocb = cycle_boundary.match_data_ocb(
self.eab, self.ocb.dtime[good_ocb], idat=iocb,
max_tol=self.max_delta, **eab_kwargs)
# Save the paired data
if iocb is not None and iocb < len(good_ocb):
self.dtime.append(self.ocb.dtime[good_ocb[iocb]])
self.ocb_ind.append(good_ocb[iocb])
self.eab_ind.append(self.eab.rec_ind)
else:
iocb = None
# Cycle to the next good EAB index
self.eab.get_next_good_ocb_ind(**eab_kwargs)
# Re-cast the class attributes as arrays
self.dtime = np.asarray(self.dtime)
self.ocb_ind = np.asarray(self.ocb_ind)
self.eab_ind = np.asarray(self.eab_ind)
# Reset the EAB index
self.eab.rec_ind = icurrent
# Set the number of good paired records
self.records = len(self.dtime)
# Set the data to the first good record
self.rec_ind = 0
return
[docs] def get_next_good_ind(self):
"""Cycle the boundary attributes to the next good paired index."""
if self.records > 0 and self.rec_ind < self.records:
# Cycle to next boundary
self.rec_ind += 1
return
[docs] def normal_coord(self, lat, lt, coords='magnetic', height=350.0,
method='ALLOWTRACE', overwrite=False):
"""Convert coordinates to be normalised relative to the EAB and OCB.
Parameters
----------
lat : float or array-like
Input latitude (degrees), must be geographic, geodetic, or AACGMV2
lt : float or array-like
Input local time (hours), must be solar or AACGMV2 magnetic
coords : str
Input coordiate system. Accepts 'magnetic', 'geocentric', or
'geodetic' (default='magnetic')
height : float or array-like
Height (km) at which AACGMV2 coordinates will be calculated, if
geographic coordinates are provided (default=350.0)
method : str
String denoting which type(s) of conversion to perform, if
geographic coordinates are provided. Expects either 'TRACE' or
'ALLOWTRACE'. See AACGMV2 for details [2]_. (default='ALLOWTRACE')
overwrite : bool
Allow the OCB and EAB AACGM boundary locations to be overwritten
(default=False)
Returns
-------
bound_lat : float or array-like
Magnetic latitude relative to EAB and OCB (degrees)
bound_mlt : float or array-like
Magnetic local time relative to EAB and OCB (hours)
ocb_lat : float or array-like
Magnetic latitude relative to only the OCB (degrees)
r_corr : float or array-like
Radius correction to OCB (degrees)
Notes
-----
Approximation - Conversion assumes a planar surface
Defines `bound_mlt` relative to only the OCB.
See Also
--------
aacgmv2
ocbpy.OCBoundary.normal_coord
"""
# Cast input as arrays
lat = np.asarray(lat)
lt = np.asarray(lt)
height = np.asarray(height)
out_shape = max([lat.shape, lt.shape, height.shape])
if out_shape == ():
lat = np.array([lat])
lt = np.array([lt])
height = np.array([height])
else:
# Ensure the input allows simple broadcasting
if lat.shape != out_shape:
if lat.shape == ():
lat = np.full(shape=out_shape, fill_value=float(lat))
else:
raise ValueError('mismatched input shape for latitude')
if lt.shape != out_shape:
if lt.shape == ():
lt = np.full(shape=out_shape, fill_value=float(lt))
else:
raise ValueError('mismatched input shape for local time')
if height.shape != out_shape:
if height.shape == ():
height = np.full(shape=out_shape, fill_value=float(height))
else:
raise ValueError('mismatched input shape for height')
# Test the dual-boundary record index
if self.rec_ind < 0 or self.rec_ind >= self.records:
if out_shape == ():
return np.nan, np.nan, np.nan, np.nan
else:
bound_lat = np.full(shape=out_shape, fill_value=np.nan)
bound_mlt = np.full(shape=out_shape, fill_value=np.nan)
ocb_lat = np.full(shape=out_shape, fill_value=np.nan)
r_corr = np.full(shape=out_shape, fill_value=np.nan)
return bound_lat, bound_mlt, ocb_lat, r_corr
# If needed, convert from geographic to magnetic coordinates
if coords.lower().find('mag') < 0:
# Convert from lt to longitude
lon = ocb_time.slt2glon(lt, self.dtime[self.rec_ind])
# If geocentric coordinates are specified, add this info to the
# method flag
if coords.lower() == 'geocentric':
method = "|".join([method, coords.upper()])
aacgm_lat, _, aacgm_mlt = aacgmv2.get_aacgm_coord_arr(
lat, lon, height, self.dtime[self.rec_ind], method)
else:
aacgm_lat = np.array(lat)
aacgm_mlt = np.array(lt)
# Calculate the coordinates relative to the OCB
ocb_lat, bound_mlt, r_corr = self.ocb.normal_coord(aacgm_lat, aacgm_mlt,
coords='magnetic',
height=height,
method=method)
bound_lat = np.array(ocb_lat)
if np.isnan(ocb_lat).all():
if out_shape == ():
return bound_lat[0], bound_mlt[0], ocb_lat[0], r_corr[0]
else:
return bound_lat, bound_mlt, ocb_lat, r_corr
# Get the boundary locations in AACGM coordinates
if not overwrite:
orig_bound = self._get_current_aacgm_boundary()
num_none = sum([obound is None for obound in orig_bound])
if len(orig_bound) == num_none:
overwrite = True
self.get_aacgm_boundary_lats(aacgm_mlt, rec_ind=self.rec_ind,
overwrite=True, set_lon=False)
ocb_aacgm_boundary = self.ocb.aacgm_boundary_lat[self.ocb.rec_ind]
eab_aacgm_boundary = self.eab.aacgm_boundary_lat[self.eab.rec_ind]
# Normalize each of the points using the correct scaling factor
imid = np.where((abs(aacgm_lat) < abs(ocb_aacgm_boundary))
& (abs(aacgm_lat) >= abs(eab_aacgm_boundary)))[0]
iout = np.where(abs(aacgm_lat) < abs(eab_aacgm_boundary))[0]
# Test to ensure that all points fall into a region
iocb = np.where(abs(ocb_lat) >= abs(self.ocb.boundary_lat))[0]
if len(iocb) + len(imid) + len(iout) < len(aacgm_lat):
msg = "not all points fall into a boundary region"
if np.isnan(ocb_aacgm_boundary).any() or np.isnan(
eab_aacgm_boundary).any():
msg += ", boundaries are poorly defined"
logger.warning(msg)
ibad = [i for i in range(len(aacgm_lat)) if i not in iocb
and i not in imid and i not in iout]
bound_lat[ibad] = np.nan
if len(imid) > 0:
bound_lat[imid] = self.ocb.boundary_lat - (
ocb_aacgm_boundary[imid] - aacgm_lat[imid]) * (
self.ocb.boundary_lat - self.eab.boundary_lat) / (
ocb_aacgm_boundary[imid] - eab_aacgm_boundary[imid])
if len(iout) > 0:
bound_lat[iout] = self.eab.boundary_lat - (
eab_aacgm_boundary[iout] - aacgm_lat[iout]) * (
self.eab.boundary_lat / eab_aacgm_boundary[iout])
# If desired, replace the boundaries
if not overwrite:
if orig_bound[2] is not None:
self.ocb.aacgm_boundary_lat[self.ocb.rec_ind] = orig_bound[2]
self.ocb.aacgm_boundary_mlt[self.ocb.rec_ind] = orig_bound[3]
if orig_bound[0] is not None:
self.eab.aacgm_boundary_lat[self.eab.rec_ind] = orig_bound[0]
self.eab.aacgm_boundary_mlt[self.eab.rec_ind] = orig_bound[1]
if out_shape == ():
return bound_lat[0], bound_mlt[0], ocb_lat[0], r_corr[0]
else:
return bound_lat, bound_mlt, ocb_lat, r_corr
[docs] def revert_coord(self, ocb_lat, ocb_mlt, r_corr=0.0, is_ocb=True,
aacgm_mlt=None, coords='magnetic', height=350.0,
method='ALLOWTRACE', overwrite=False):
"""Convert from OCB or dual-boundary into AACGM co-ordinates.
Parameters
----------
ocb_lat : float or array-like
Input OCB or dual-boundary latitude in degrees
ocb_mlt : float or array-like
Input OCB/dual-boundary local time in hours
r_corr : float or array-like
Input OCB radial correction in degrees, may be a function of
AACGM MLT (default=0.0)
is_ocb : bool
Specifies that the input of `ocb_lat` is in OCB coordinates if True
or in dual-boundary coordinates if False. If False, `aacgm_mlt`
must be provided (default=True)
aacgm_mlt : float, array-like, or NoneType
Output AACGM MLT of the dual-boundary data, only used if `is_ocb`
is False (default=None)
coords : str
Output coordiate system. Accepts 'magnetic', 'geocentric', or
'geodetic' (default='magnetic')
height : float or array-like
Geocentric height above sea level (km) at which AACGMV2 coordinates
will be calculated, if geographic coordinates are desired
(default=350.0)
method : str
String denoting which type(s) of conversion to perform, if
geographic coordinates are provided. Expects either 'TRACE' or
'ALLOWTRACE'. See AACGMV2 for details [2]_. (default='ALLOWTRACE')
overwrite : bool
Allow the OCB and EAB AACGM boundary locations to be overwritten
(default=False)
Returns
-------
lat : float or array-like
latitude (degrees)
lt : float or array-like
local time (hours)
Raises
------
ValueError
When necessary inputs are not fully supplied
Notes
-----
Approximation - Conversion assumes a planar surface
See Also
--------
aacgmv2
ocbpy.OCBoundary.revert_coord
"""
# Cast input as arrays and prepare the output
ocb_lat = np.asarray(ocb_lat)
ocb_mlt = np.asarray(ocb_mlt)
height = np.asarray(height)
out_shape = max([ocb_lat.shape, ocb_mlt.shape, height.shape])
if out_shape == ():
ocb_lat = np.array([ocb_lat])
ocb_mlt = np.array([ocb_mlt])
height = np.array([height])
else:
# Ensure the input allows simple broadcasting
if ocb_lat.shape != out_shape:
if ocb_lat.shape == ():
ocb_lat = np.full(shape=out_shape,
fill_value=float(ocb_lat))
else:
raise ValueError('mismatched input shape for OCB latitude')
if ocb_mlt.shape != out_shape:
if ocb_mlt.shape == ():
ocb_mlt = np.full(shape=out_shape,
fill_value=float(ocb_mlt))
else:
raise ValueError('mismatched input shape for OCB MLT')
if height.shape != out_shape:
if height.shape == ():
height = np.full(shape=out_shape, fill_value=float(height))
else:
raise ValueError('mismatched input shape for height')
# Get the OCB reversion
lat, lt = self.ocb.revert_coord(ocb_lat, ocb_mlt, r_corr=r_corr,
coords=coords, height=height,
method=method)
# If not already flagged, see if all OCB by location
if not is_ocb:
iocb = np.where(abs(ocb_lat) >= abs(self.ocb.boundary_lat))[0]
if len(ocb_lat) == len(iocb):
is_ocb = True
# Continue calculating the output for the other regions, if needed
if not is_ocb:
# Ensure the AACGM MLT was provided on input
if aacgm_mlt is None:
raise ValueError(
''.join(['cannot revert dual-boundary coordinates without',
' the AACGM MLT']))
aacgm_mlt = np.asarray(aacgm_mlt)
if aacgm_mlt.shape == ():
if out_shape == ():
aacgm_mlt = np.array([aacgm_mlt])
else:
aacgm_mlt = np.full(shape=out_shape,
fill_value=float(aacgm_mlt))
# Get the boundary locations in AACGM coordinates
if not overwrite:
orig_bound = self._get_current_aacgm_boundary()
num_none = sum([obound is None for obound in orig_bound])
if len(orig_bound) == num_none:
overwrite = True
self.get_aacgm_boundary_lats(aacgm_mlt, rec_ind=self.rec_ind,
overwrite=True, set_lon=False)
ocb_aacgm_boundary = self.ocb.aacgm_boundary_lat[self.ocb.rec_ind]
eab_aacgm_boundary = self.eab.aacgm_boundary_lat[self.eab.rec_ind]
# Raise warning for poorly defined boundaries, may cause NaN output
if np.isnan(ocb_aacgm_boundary).any() or np.isnan(
eab_aacgm_boundary).any():
msg = "".join(["not all points fall into a boundary region",
", boundaries are poorly defined"])
logger.warning(msg)
# Revert each of the points using the correct scaling factor
imid = np.where((abs(ocb_lat) < abs(self.ocb.boundary_lat))
& (abs(ocb_lat) >= abs(self.eab.boundary_lat)))[0]
iout = np.where(abs(ocb_lat) < abs(self.eab.boundary_lat))[0]
if len(imid) > 0:
lat[imid] = ocb_aacgm_boundary[imid] - (
self.ocb.boundary_lat - ocb_lat[imid]) * (
ocb_aacgm_boundary[imid] - eab_aacgm_boundary[imid]) / (
self.ocb.boundary_lat - self.eab.boundary_lat)
lt[imid] = aacgm_mlt[imid]
if len(iout) > 0:
lat[iout] = eab_aacgm_boundary[iout] - (
self.eab.boundary_lat - ocb_lat[iout]) * (
eab_aacgm_boundary[iout] / self.eab.boundary_lat)
lt[iout] = aacgm_mlt[iout]
# If desired, replace the boundaries
if not overwrite:
if orig_bound[2] is not None:
self.ocb.aacgm_boundary_lat[
self.ocb.rec_ind] = orig_bound[2]
self.ocb.aacgm_boundary_mlt[
self.ocb.rec_ind] = orig_bound[3]
if orig_bound[0] is not None:
self.eab.aacgm_boundary_lat[
self.eab.rec_ind] = orig_bound[0]
self.eab.aacgm_boundary_mlt[
self.eab.rec_ind] = orig_bound[1]
# If needed, convert from magnetic to geographic coordinates
if coords.lower().find('mag') < 0:
imag = list(imid) + list(iout)
# Convert from mlt to longitude
lon = aacgmv2.convert_mlt(aacgm_mlt[imag],
self.dtime[self.rec_ind], m2a=True)
# If geocentric coordinates are specified, add this info to the
# method flag
if coords.lower() == 'geocentric':
method = "|".join([method, coords.upper()])
method = "|".join([method, "A2G"])
# Convert from magnetic coordinates to geo coordinates
lat[imag], lon, _ = aacgmv2.convert_latlon_arr(
lat[imag], lon, height, self.dtime[self.rec_ind], method)
# Convert from longitude to solar local time
lt[imag] = ocb_time.glon2slt(lon, self.dtime[self.rec_ind])
if out_shape == ():
return lat[0], lt[0]
else:
return lat, lt
[docs] def get_aacgm_boundary_lats(self, aacgm_mlt, rec_ind=None,
overwrite=False, set_lon=True):
"""Calculate the OCB latitude in AACGM coordinates at specified MLTs.
Parameters
----------
aacgm_mlt : int, float, or array-like
AACGM longitude location(s) (in degrees) for which the OCB latitude
will be calculated.
rec_ind : int, array-like, or NoneType
Record index for which the OCB AACGM latitude will be calculated,
or None to calculate all boundary locations (default=None).
overwrite : bool
Overwrite previous boundary locations if this time already has
calculated boundary latitudes for a different set of input
longitudes (default=False).
set_lon : bool
Calculate the AACGM longitude of the OCB alongside the MLT
(default=True).
See Also
--------
ocbpy.OCBoundary.get_aacgm_boundary_lat
"""
# Get the desired EAB and OCB record indices
if rec_ind is None:
eab_rec_ind = None
ocb_rec_ind = None
else:
eab_rec_ind = self.eab_ind[rec_ind]
ocb_rec_ind = self.ocb_ind[rec_ind]
# Calculate the boundary locations
self.eab.get_aacgm_boundary_lat(aacgm_mlt, rec_ind=eab_rec_ind,
overwrite=overwrite, set_lon=set_lon)
self.ocb.get_aacgm_boundary_lat(aacgm_mlt, rec_ind=ocb_rec_ind,
overwrite=overwrite, set_lon=set_lon)
return
[docs] def calc_r(self, bound_lat, bound_mlt, aacgm_mlt, r_corr, overwrite=False):
"""Calculate the scaled and unscaled radius at a normalised co-ordinate.
Parameters
----------
bound_lat : array-like or float
Normalised dual-boundary latitude in degrees
bound_mlt : array-like or float
Normalised dual-boundary MLT in hours
aacgm_mlt : array-like or float
MLT in AACGM coordinates in hours
r_corr : array-like or float
OCB radial correction in degrees
overwrite : bool
Overwrite previous boundary locations if this time already has
calculated boundary latitudes for a different set of input
longitudes (default=False).
Returns
-------
scaled_r : array-like
Scaled radius for the region (OCB, EAB, Sub-auroral) in degrees
unscaled_r : array-like
Unscaled radius for the region (OCB, EAB, Sub-auroral) in degrees
"""
# Ensure all data is array-like
bound_lat = np.asarray(bound_lat)
bound_mlt = np.asarray(bound_mlt)
aacgm_mlt = np.asarray(aacgm_mlt)
r_corr = np.asarray(r_corr)
isfloat = False
if bound_lat.shape == ():
bound_lat = np.array([bound_lat])
bound_mlt = np.array([bound_mlt])
aacgm_mlt = np.array([aacgm_mlt])
r_corr = np.array([r_corr])
isfloat = True
# Initialize the output, start by assuming the data is inside the OCB
out_shape = max([bound_lat.shape, bound_mlt.shape, r_corr.shape])
scaled_r = np.full(shape=out_shape,
fill_value=90.0 - abs(self.ocb.boundary_lat))
if self.rec_ind < 0 or self.rec_ind >= self.records:
unscaled_r = np.full(shape=out_shape, fill_value=np.nan)
return scaled_r, unscaled_r
if out_shape == r_corr.shape:
unscaled_r = self.ocb.r[self.ocb_ind[self.rec_ind]] + r_corr
else:
unscaled_r = np.full(shape=out_shape, fill_value=self.ocb.r[
self.ocb_ind[self.rec_ind]] + r_corr)
# Identify points in the other regions
imid = np.where((abs(bound_lat) < abs(self.ocb.boundary_lat))
& (abs(bound_lat) >= abs(self.eab.boundary_lat)))[0]
iout = np.where(abs(bound_lat) < abs(self.eab.boundary_lat))[0]
# Get the boundary locations in AACGM coordinates
if not overwrite:
orig_bound = self._get_current_aacgm_boundary()
num_none = sum([obound is None for obound in orig_bound])
if len(orig_bound) == num_none:
overwrite = True
self.get_aacgm_boundary_lats(aacgm_mlt, rec_ind=self.rec_ind,
overwrite=True, set_lon=False)
ocb_aacgm_boundary = self.ocb.aacgm_boundary_lat[self.ocb.rec_ind]
eab_aacgm_boundary = self.eab.aacgm_boundary_lat[self.eab.rec_ind]
# Calculate the radii in the auroral region
if len(imid) > 0:
scaled_r[imid] = abs(self.ocb.boundary_lat - self.eab.boundary_lat)
unscaled_r[imid] = abs(ocb_aacgm_boundary[imid]
- eab_aacgm_boundary[imid])
if len(iout) > 0:
scaled_r[iout] = abs(self.eab.boundary_lat)
unscaled_r[iout] = abs(eab_aacgm_boundary[iout])
# If desired, replace the boundaries
if not overwrite:
if orig_bound[2] is not None:
self.ocb.aacgm_boundary_lat[self.ocb.rec_ind] = orig_bound[2]
self.ocb.aacgm_boundary_mlt[self.ocb.rec_ind] = orig_bound[3]
if orig_bound[0] is not None:
self.eab.aacgm_boundary_lat[self.eab.rec_ind] = orig_bound[0]
self.eab.aacgm_boundary_mlt[self.eab.rec_ind] = orig_bound[1]
if isfloat:
return scaled_r[0], unscaled_r[0]
else:
return scaled_r, unscaled_r