def __getter__(self, name, instantiate=True):
"""Loads the specified name from a file on disk.
Parameters:
name (key type): The canonical mapping key to get the dataObject. By default
the baseFolder class uses a :py:class:`regexpDict` to store objects in.
Keyword Arguments:
instatiate (bool): IF True (default) then always return a :py:class:`Stoner.Core.Data` object. If False,
the __getter__ method may return a key that can be used by it later to actually get the
:py:class:`Stoner.Core.Data` object.
Returns:
(metadataObject): The metadataObject
"""
assertion(name is not None, "Cannot get an anonympus entry!")
try: # Try the parent methods first
return super(DiskBasedFolder,
self).__getter__(name, instantiate=instantiate)
except (AttributeError, IndexError, KeyError):
pass
# Find a filename and load
fname = name if path.exists(name) else path.join(self.directory, name)
try:
tmp = self.type(self.loader(fname, **self.extra_args))
except StonerUnrecognisedFormat:
return None
if not isinstance(getattr(tmp, "filename", None), string_types):
tmp.filename = path.basename(fname)
# Process file hooks
tmp = self.on_load_process(tmp)
tmp = self._update_from_object_attrs(tmp)
# Store the result
self.__setter__(name, tmp)
return tmp
def __parse_VSM(self, header_line=3, data_line=3, header_delim=","):
"""An intrernal function for parsing deliminated data without a leading column of metadata.copy
Keyword Arguments:
header_line (int): The line in the file that contains the column headers.
If None, then column headers are auotmatically generated.
data_line (int): The line on which the data starts
header_delim (strong): The delimiter used for separating header values
Returns:
Nothing, but modifies the current object.
Note:
The default values are configured fir read VSM data files
"""
try:
with io.open(self.filename, errors="ignore",
encoding="utf-8") as f:
for i, line in enumerate(f):
if i == 0:
self["Timestamp"] = line.strip()
check = datetime.strptime(self["Timestamp"],
"%a %b %d %H:%M:%S %Y")
if check is None:
raise Core.StonerLoadError("Not a VSM file ?")
elif i == 1:
assertion(line.strip() == "")
elif i == 2:
header_string = line.strip()
elif i == header_line:
unit_string = line.strip()
column_headers = [
"{} ({})".format(h.strip(), u.strip())
for h, u in zip(header_string.split(header_delim),
unit_string.split(header_delim))
]
elif i > 3:
break
except (StonerAssertionError, ValueError, AssertionError,
TypeError) as e:
raise Core.StonerLoadError("Not a VSM File" + str(e.args))
self.data = np.genfromtxt(
self.filename,
dtype="float",
usemask=True,
skip_header=data_line - 1,
missing_values=["6:0", "---"],
invalid_raise=False,
)
self.data = np.ma.mask_rows(self.data)
cols = self.data.shape[1]
self.data = np.reshape(self.data.compressed(), (-1, cols))
self.column_headers = column_headers
self.setas(x="H_vsm (T)", y="m (emu)") # pylint: disable=not-callable
def crop_text(self, copy=False):
"""Crop the bottom text area from a standard Kermit image stack
Returns:
(self):
cropped image
"""
assertion(
(self[0].shape == AN_IM_SIZE or self[0].shape == IM_SIZE), "Need a full sized Kerr image to crop"
) # check it's a normal image
crop = (0, IM_SIZE[1], 0, IM_SIZE[0])
self.crop_stack(box=crop)
def _get_scalebar(self):
"""Get the length in pixels of the image scale bar"""
box = (0, 419, 519, 520) # row where scalebar exists
im = self.crop(box=box, copy=True)
im = im.astype(float)
im = (im - im.min()) / (im.max() - im.min())
im = exposure.rescale_intensity(im, in_range=(0.49, 0.5)) # saturate black and white pixels
im = exposure.rescale_intensity(im) # make sure they're black and white
im = np.diff(im[0]) # 1d numpy array, differences
lim = [np.where(im > 0.9)[0][0], np.where(im < -0.9)[0][0]] # first occurance of both cases
assertion(len(lim) == 2, "Couldn't find scalebar")
return lim[1] - lim[0]
def _read_uvwdata(self, filename, fmt, lineno):
"""Read the numerical data taking account of the format."""
if fmt == "Text":
uvwdata = np.genfromtxt(self.filename, skip_header=lineno + 2)
elif fmt == "Binary 4":
if self["version"] == 1:
dt = np.dtype(">f4")
else:
dt = np.dtype("<f4")
with io.open(filename, "rb") as bindata:
bindata.seek(self._ptr)
uvwdata = np.fromfile(bindata,
dtype=dt,
count=1 +
self["xnodes"] * self["ynodes"] *
self["znodes"] * self["valuedim"])
assertion(
uvwdata[0] == 1234567.0,
"Binary 4 format check value incorrect ! Actual Value was {}"
.format(uvwdata[0]),
)
uvwdata = uvwdata[1:]
uvwdata = np.reshape(uvwdata, (-1, self["valuedim"]))
elif fmt == "Binary 8":
if self["version"] == 1:
dt = np.dtype(">f8")
else:
dt = np.dtype("<f8")
with io.open(filename, "rb") as bindata:
bindata.seek(self._ptr)
uvwdata = np.fromfile(bindata,
dtype=dt,
count=1 +
self["xnodes"] * self["ynodes"] *
self["znodes"] * self["valuedim"])
assertion(
(uvwdata[0] == 123456789012345.0),
"Binary 4 format check value incorrect ! Actual Value was {}"
.format(uvwdata[0]),
)
uvwdata = np.reshape(uvwdata, (-1, self["valuedim"]))
else:
raise StonerLoadError("Unknow OVF Format {}".format(fmt))
return uvwdata
def peaks(self, **kargs):
"""Locates peaks and/or troughs in a column of data by using SG-differentiation.
Args:
ycol (index):
the column name or index of the data in which to search for peaks
width (int or float):
the expected minium halalf-width of a peak in terms of the number of data points (int) or distance
in x (float). This is used in the differnetiation code to find local maxima. Bigger equals less
sensitive to experimental noise, smaller means better eable to see sharp peaks
poly (int):
the order of polynomial to use when differentiating the data to locate a peak. Must >=2, higher numbers
will find sharper peaks more accurately but at the risk of finding more false positives.
Keyword Arguments:
significance (float):
used to decide whether a local maxmima is a significant peak. Essentially just the curvature
of the data. Bigger means less sensistive, smaller means more likely to detect noise. Default is the
maximum curvature/(2*width)
xcol (index or None):
name or index of data column that p[rovides the x-coordinate (default None)
peaks (bool):
select whether to measure peaks in data (default True)
troughs (bool):
select whether to measure troughs in data (default False)
sort (bool):
Sor the results by significance of peak
modify (book):
If true, then the returned object is a copy of self with only the peaks/troughs left in the data.
full_data (bool):
If True (default) then all columns of the data at which peaks in the *ycol* column are found.
*modify* true implies *full_data* is also true. If *full_data* is False, then only the x-column
values of the peaks are returned.
Returns:
(various):
If *modify* is true, then returns a the AnalysisMixin with the data set to just the peaks/troughs.
If *modify* is false (default), then the return value depends on *ycol* and *xcol*. If *ycol* is
not None and *xcol* is None, then returns conplete rows of data corresponding to the found
peaks/troughs. If *xcol* is not None, or *ycol* is None and *xcol* is None, then returns a 1D array
of the x positions of the peaks/troughs.
See Also:
User guide section :ref:`peak_finding`
"""
width = kargs.pop("width", int(len(self) / 20))
peaks = kargs.pop("peaks", True)
troughs = kargs.pop("troughs", False)
poly = kargs.pop("poly", 2)
assertion(
poly >= 2,
"poly must be at least 2nd order in peaks for checking for significance of peak or trough"
)
sort = kargs.pop("sort", False)
modify = kargs.pop("modify", False)
full_data = kargs.pop("full_data", True)
_ = self._col_args(scalar=False,
xcol=kargs.pop("xcol", None),
ycol=kargs.pop("ycol", None))
xcol, ycol = _.xcol, _.ycol
if isIterable(ycol):
ycol = ycol[0]
if isinstance(
width,
float): # Convert a floating point width unto an integer.
xmin, xmax = self.span(xcol)
width = int(len(self) * width / (xmax - xmin))
width = max(width, poly + 1)
setas = self.setas.clone # pylint: disable=E0203
self.setas = ""
d1 = self.SG_Filter(ycol, xcol=xcol, points=width, poly=poly,
order=1).ravel()
d2 = self.SG_Filter(
ycol, xcol=xcol, points=2 * width, poly=poly,
order=2).ravel() # 2nd differential requires more smoothing
# We're going to ignore the start and end of the arrays
index_offset = int(width / 2)
d1 = d1[index_offset:-index_offset]
d2 = d2[index_offset:-index_offset]
# Pad the ends of d2 with the mean value
pad = np.mean(d2[index_offset:-index_offset])
d2[:index_offset] = pad
d2[-index_offset:] = pad
# Set the significance from the 2nd ifferential if not already set
significance = kargs.pop(
"significance",
np.max(np.abs(d2)) /
(2 * width)) # Base an apriori significance on max d2y/dx2 / 20
if isinstance(significance,
int): # integer significance is inverse to floating
significance = np.max(
np.abs(d2)
) / significance # Base an apriori significance on max d2y/dx2 / 20
d2_interp = interp1d(np.arange(len(d2)), d2, kind="cubic")
# Ensure we have some X-data
if xcol is None:
xdata = np.arange(len(self))
else:
xdata = self.column(xcol)
xdata = interp1d(np.arange(len(self)), xdata, kind="cubic")
possible_peaks = np.array(
threshold(0, d1, rising=troughs, falling=peaks))
curvature = np.abs(d2_interp(possible_peaks))
# Filter just the significant peaks
possible_peaks = np.array([
p for ix, p in enumerate(possible_peaks)
if abs(curvature[ix]) > significance
])
# Sort in order of significance
if sort:
possible_peaks = np.take(
possible_peaks, np.argsort(np.abs(d2_interp(possible_peaks))))
xdat = xdata(possible_peaks + index_offset)
if modify:
self.data = self.interpolate(xdat, xcol=xcol, kind="cubic")
ret = self
elif full_data:
ret = self.interpolate(xdat, kind="cubic", xcol=False)
else:
ret = xdat
self.setas = setas
# Return - but remembering to add back on the offset that we took off due to differentials not working at
# start and end
return ret
def _load(self, filename=None, *args, **kargs):
"""Load function. File format has space delimited columns from row 3 onwards."""
if filename is None or not filename:
self.get_filename("r")
else:
self.filename = filename
self._ptr = 0
with io.open(self.filename, "r", errors="ignore",
encoding="utf-8") as data: # Slightly ugly text handling
line = next(data)
self._ptr += len(line)
line = line.strip()
if "OOMMF: rectangular mesh" in line:
if "v1.0" in line:
self["version"] = 1
elif "v2.0" in line:
self["version"] = 2
else:
raise StonerLoadError(
"Cannot determine version of OOMMFF file")
else: # bug out oif we don't like the header
raise StonerLoadError(
"Not n OOMMF OVF File: opening line eas {}".format(line))
pattern = re.compile(r"#\s*([^\:]+)\:\s+(.*)$")
i = None
for i, line in enumerate(data):
self._ptr += len(line)
line.strip()
if line.startswith(
"# Begin: Data"): # marks the start of the trext
break
elif line.startswith("# Begin:") or line.startswith("# End:"):
continue
else:
res = pattern.match(line)
if res is not None:
key = res.group(1)
val = res.group(2)
self[key] = string_to_type(val)
else:
raise StonerLoadError("Failed to understand metadata")
fmt = re.match(r".*Data\s+(.*)", line).group(1).strip()
assertion(
(self["meshtype"] == "rectangular"),
"Sorry only OVF files with rectnagular meshes are currently supported.",
)
if self["version"] == 1:
if self["meshtype"] == "rectangular":
self["valuedim"] = 3
else:
self["valuedim"] = 6
uvwdata = self._read_uvwdata(filename, fmt, i)
x = (np.linspace(self["xmin"], self["xmax"], self["xnode"] + 1)[:-1] +
self["xbase"]) * 1e9
y = (np.linspace(self["ymin"], self["ymax"], self["ynode"] + 1)[:-1] +
self["ybase"]) * 1e9
z = (np.linspace(self["zmin"], self["zmax"], self["znode"] + 1)[:-1] +
self["zbase"]) * 1e9
(y, z, x) = (np.ravel(i) for i in np.meshgrid(y, z, x))
self.data = np.column_stack((x, y, z, uvwdata))
column_headers = ["X (nm)", "Y (nm)", "Z (nm)", "U", "V", "W"]
self.setas = "xyzuvw"
self.column_headers = column_headers
return self
