Source code for sasmodels.data

"""
SAS data representations.

Plotting functions for data sets:

    :func:`plot_data` plots the data file.

    :func:`plot_theory` plots a calculated result from the model.

Wrappers for the sasview data loader and data manipulations:

    :func:`load_data` loads a sasview data file.

    :func:`set_beam_stop` masks the beam stop from the data.

    :func:`set_half` selects the right or left half of the data, which can
    be useful for shear measurements which have not been properly corrected
    for path length and reflections.

    :func:`set_top` cuts the top part off the data.


Empty data sets for evaluating models without data:

    :func:`empty_data1D` creates an empty dataset, which is useful for plotting
    a theory function before the data is measured.

    :func:`empty_data2D` creates an empty 2D dataset.

Note that the empty datasets use a minimal representation of the SasView
objects so that models can be run without SasView on the path.  You could
also use these for your own data loader.

"""
import traceback

import numpy as np  # type: ignore
from numpy import sqrt, sin, cos, pi

# pylint: disable=unused-import
try:
    from typing import Union, Dict, List, Optional, Tuple, Callable
    Data = Union["Data1D", "Data2D", "SesansData"]
    OptArray = Optional[np.ndarray]
    OptLimits = Optional[Tuple[float, float]]
except ImportError:
    pass
# pylint: enable=unused-import

[docs]def load_data(filename, index=0): # type: (str, int) -> Data """ Load data using a sasview loader. """ from sas.sascalc.dataloader.loader import Loader # type: ignore loader = Loader() # Allow for one part in multipart file if '[' in filename: filename, indexstr = filename[:-1].split('[') index = int(indexstr) datasets = loader.load(filename) if not datasets: # None or [] raise IOError("Data %r could not be loaded" % filename) if not isinstance(datasets, list): datasets = [datasets] for data in datasets: if hasattr(data, 'x'): data.qmin, data.qmax = data.x.min(), data.x.max() data.mask = (np.isnan(data.y) if data.y is not None else np.zeros_like(data.x, dtype='bool')) elif hasattr(data, 'qx_data'): data.mask = ~data.mask return datasets[index] if index != 'all' else datasets
[docs]def set_beam_stop(data, radius, outer=None): # type: (Data, float, Optional[float]) -> None """ Add a beam stop of the given *radius*. If *outer*, make an annulus. """ from sas.sascalc.dataloader.manipulations import Ringcut if hasattr(data, 'qx_data'): data.mask = Ringcut(0, radius)(data) if outer is not None: data.mask += Ringcut(outer, np.inf)(data) else: data.mask = (data.x < radius) if outer is not None: data.mask |= (data.x >= outer)
[docs]def set_half(data, half): # type: (Data, str) -> None """ Select half of the data, either "right" or "left". """ from sas.sascalc.dataloader.manipulations import Boxcut if half == 'right': data.mask += \ Boxcut(x_min=-np.inf, x_max=0.0, y_min=-np.inf, y_max=np.inf)(data) if half == 'left': data.mask += \ Boxcut(x_min=0.0, x_max=np.inf, y_min=-np.inf, y_max=np.inf)(data)
[docs]def set_top(data, cutoff): # type: (Data, float) -> None """ Chop the top off the data, above *cutoff*. """ from sas.sascalc.dataloader.manipulations import Boxcut data.mask += \ Boxcut(x_min=-np.inf, x_max=np.inf, y_min=-np.inf, y_max=cutoff)(data)
[docs]class Data1D(object): """ 1D data object. Note that this definition matches the attributes from sasview, with some generic 1D data vectors and some SAS specific definitions. Some refactoring to allow consistent naming conventions between 1D, 2D and SESANS data would be helpful. **Attributes** *x*, *dx*: $q$ vector and gaussian resolution *y*, *dy*: $I(q)$ vector and measurement uncertainty *mask*: values to include in plotting/analysis *dxl*: slit widths for slit smeared data, with *dx* ignored *qmin*, *qmax*: range of $q$ values in *x* *filename*: label for the data line *_xaxis*, *_xunit*: label and units for the *x* axis *_yaxis*, *_yunit*: label and units for the *y* axis """
[docs] def __init__(self, x=None, y=None, dx=None, dy=None): # type: (OptArray, OptArray, OptArray, OptArray) -> None self.x, self.y, self.dx, self.dy = x, y, dx, dy self.dxl = None self.filename = None self.qmin = x.min() if x is not None else np.NaN self.qmax = x.max() if x is not None else np.NaN # TODO: why is 1D mask False and 2D mask True? self.mask = (np.isnan(y) if y is not None else np.zeros_like(x, 'b') if x is not None else None) self._xaxis, self._xunit = "x", "" self._yaxis, self._yunit = "y", ""
[docs] def xaxis(self, label, unit): # type: (str, str) -> None """ set the x axis label and unit """ self._xaxis = label self._xunit = unit
[docs] def yaxis(self, label, unit): # type: (str, str) -> None """ set the y axis label and unit """ self._yaxis = label self._yunit = unit
[docs]class SesansData(Data1D): """ SESANS data object. This is just :class:`Data1D` with a wavelength parameter. *x* is spin echo length and *y* is polarization (P/P0). """ isSesans = True
[docs] def __init__(self, **kw): Data1D.__init__(self, **kw) self.lam = None # type: OptArray
[docs]class Data2D(object): """ 2D data object. Note that this definition matches the attributes from sasview. Some refactoring to allow consistent naming conventions between 1D, 2D and SESANS data would be helpful. **Attributes** *qx_data*, *dqx_data*: $q_x$ matrix and gaussian resolution *qy_data*, *dqy_data*: $q_y$ matrix and gaussian resolution *data*, *err_data*: $I(q)$ matrix and measurement uncertainty *mask*: values to exclude from plotting/analysis *qmin*, *qmax*: range of $q$ values in *x* *filename*: label for the data line *_xaxis*, *_xunit*: label and units for the *x* axis *_yaxis*, *_yunit*: label and units for the *y* axis *_zaxis*, *_zunit*: label and units for the *y* axis *Q_unit*, *I_unit*: units for Q and intensity *x_bins*, *y_bins*: grid steps in *x* and *y* directions """
[docs] def __init__(self, x=None, y=None, z=None, dx=None, dy=None, dz=None): # type: (OptArray, OptArray, OptArray, OptArray, OptArray, OptArray) -> None self.qx_data, self.dqx_data = x, dx self.qy_data, self.dqy_data = y, dy self.data, self.err_data = z, dz self.mask = (np.isnan(z) if z is not None else np.zeros_like(x, dtype='bool') if x is not None else None) self.q_data = np.sqrt(x**2 + y**2) self.qmin = 1e-16 self.qmax = np.inf self.detector = [] self.source = Source() self.Q_unit = "1/A" self.I_unit = "1/cm" self.xaxis("Q_x", "1/A") self.yaxis("Q_y", "1/A") self.zaxis("Intensity", "1/cm") self._xaxis, self._xunit = "x", "" self._yaxis, self._yunit = "y", "" self._zaxis, self._zunit = "z", "" self.x_bins, self.y_bins = None, None self.filename = None
[docs] def xaxis(self, label, unit): # type: (str, str) -> None """ set the x axis label and unit """ self._xaxis = label self._xunit = unit
[docs] def yaxis(self, label, unit): # type: (str, str) -> None """ set the y axis label and unit """ self._yaxis = label self._yunit = unit
[docs] def zaxis(self, label, unit): # type: (str, str) -> None """ set the y axis label and unit """ self._zaxis = label self._zunit = unit
[docs]class Vector(object): """ 3-space vector of *x*, *y*, *z* """
[docs] def __init__(self, x=None, y=None, z=None): # type: (float, float, Optional[float]) -> None self.x, self.y, self.z = x, y, z
[docs]class Detector(object): """ Detector attributes. """
[docs] def __init__(self, pixel_size=(None, None), distance=None): # type: (Tuple[float, float], float) -> None self.pixel_size = Vector(*pixel_size) self.distance = distance
[docs]class Source(object): """ Beam attributes. """
[docs] def __init__(self): # type: () -> None self.wavelength = np.NaN self.wavelength_unit = "A"
[docs]class Sample(object): """ Sample attributes. """
[docs] def __init__(self): # type: () -> None pass
[docs]def empty_data1D(q, resolution=0.0, L=0., dL=0.): # type: (np.ndarray, float, float, float) -> Data1D r""" Create empty 1D data using the given *q* as the x value. rms *resolution* $\Delta q/q$ defaults to 0%. If wavelength *L* and rms wavelength divergence *dL* are defined, then *resolution* defines rms $\Delta \theta/\theta$ for the lowest *q*, with $\theta$ derived from $q = 4\pi/\lambda \sin(\theta)$. """ #Iq = 100 * np.ones_like(q) #dIq = np.sqrt(Iq) Iq, dIq = None, None q = np.asarray(q) if L != 0 and resolution != 0: theta = np.arcsin(q*L/(4*pi)) dtheta = theta[0]*resolution ## Solving Gaussian error propagation from ## Dq^2 = (dq/dL)^2 DL^2 + (dq/dtheta)^2 Dtheta^2 ## gives ## (Dq/q)^2 = (DL/L)**2 + (Dtheta/tan(theta))**2 ## Take the square root and multiply by q, giving ## Dq = (4*pi/L) * sqrt((sin(theta)*dL/L)**2 + (cos(theta)*dtheta)**2) dq = (4*pi/L) * sqrt((sin(theta)*dL/L)**2 + (cos(theta)*dtheta)**2) else: dq = resolution * q data = Data1D(q, Iq, dx=dq, dy=dIq) data.filename = "fake data" return data
[docs]def empty_data2D(qx, qy=None, resolution=0.0): # type: (np.ndarray, OptArray, float) -> Data2D """ Create empty 2D data using the given mesh. If *qy* is missing, create a square mesh with *qy=qx*. *resolution* dq/q defaults to 5%. """ if qy is None: qy = qx qx, qy = np.asarray(qx), np.asarray(qy) # 5% dQ/Q resolution Qx, Qy = np.meshgrid(qx, qy) Qx, Qy = Qx.flatten(), Qy.flatten() Iq = 100 * np.ones_like(Qx) # type: np.ndarray dIq = np.sqrt(Iq) if resolution != 0: # https://www.ncnr.nist.gov/staff/hammouda/distance_learning/chapter_15.pdf # Should have an additional constant which depends on distances and # radii of the aperture, pixel dimensions and wavelength spread # Instead, assume radial dQ/Q is constant, and perpendicular matches # radial (which instead it should be inverse). Q = np.sqrt(Qx**2 + Qy**2) dqx = resolution * Q dqy = resolution * Q else: dqx = dqy = None data = Data2D(x=Qx, y=Qy, z=Iq, dx=dqx, dy=dqy, dz=dIq) data.x_bins = qx data.y_bins = qy data.filename = "fake data" # pixel_size in mm, distance in m detector = Detector(pixel_size=(5, 5), distance=4) data.detector.append(detector) data.source.wavelength = 5 # angstroms data.source.wavelength_unit = "A" return data
[docs]def plot_data(data, view=None, limits=None): # type: (Data, str, OptLimits) -> None """ Plot data loaded by the sasview loader. *data* is a sasview data object, either 1D, 2D or SESANS. *view* is log or linear. *limits* sets the intensity limits on the plot; if None then the limits are inferred from the data. """ # Note: kind of weird using the plot result functions to plot just the # data, but they already handle the masking and graph markup already, so # do not repeat. if hasattr(data, 'isSesans') and data.isSesans: _plot_result_sesans(data, None, None, use_data=True, limits=limits) elif hasattr(data, 'qx_data') and not getattr(data, 'radial', False): _plot_result2D(data, None, None, view, use_data=True, limits=limits) else: _plot_result1D(data, None, None, view, use_data=True, limits=limits)
[docs]def plot_theory(data, theory, resid=None, view=None, use_data=True, limits=None, Iq_calc=None): # type: (Data, OptArray, OptArray, str, bool, OptLimits, OptArray) -> None """ Plot theory calculation. *data* is needed to define the graph properties such as labels and units, and to define the data mask. *theory* is a matrix of the same shape as the data. *view* is log or linear *use_data* is True if the data should be plotted as well as the theory. *limits* sets the intensity limits on the plot; if None then the limits are inferred from the data. *Iq_calc* is the raw theory values without resolution smearing """ if hasattr(data, 'isSesans') and data.isSesans: _plot_result_sesans(data, theory, resid, use_data=True, limits=limits) elif hasattr(data, 'qx_data') and not getattr(data, 'radial', False): _plot_result2D(data, theory, resid, view, use_data, limits=limits) else: _plot_result1D(data, theory, resid, view, use_data, limits=limits, Iq_calc=Iq_calc)
[docs]def protect(func): # type: (Callable) -> Callable """ Decorator to wrap calls in an exception trapper which prints the exception and continues. Keyboard interrupts are ignored. """ def wrapper(*args, **kw): """ Trap and print errors from function. """ try: return func(*args, **kw) except Exception: traceback.print_exc() return wrapper
[docs]@protect def _plot_result1D(data, theory, resid, view, use_data, limits=None, Iq_calc=None): # type: (Data1D, OptArray, OptArray, str, bool, OptLimits, OptArray) -> None """ Plot the data and residuals for 1D data. """ import matplotlib.pyplot as plt # type: ignore from numpy.ma import masked_array, masked # type: ignore # Default to 'log' view if view is None: view = 'log' if getattr(data, 'radial', False): data.x = data.q_data data.y = data.data use_data = use_data and data.y is not None use_theory = theory is not None use_resid = resid is not None use_calc = use_theory and Iq_calc is not None num_plots = (use_data or use_theory) + use_calc + use_resid non_positive_x = (data.x <= 0.0).any() scale = 1e8 * data.x**4 if view == 'q4' else 1.0 if use_data or use_theory: if num_plots > 1: plt.subplot(1, num_plots, 1) #print(vmin, vmax) all_positive = True some_present = False if use_data: mdata = masked_array(data.y, data.mask.copy()) mdata[~np.isfinite(mdata)] = masked if view == 'log': mdata[mdata <= 0] = masked plt.errorbar(data.x, scale*mdata, yerr=scale*data.dy, fmt='.') all_positive = all_positive and (mdata > 0).all() some_present = some_present or (mdata.count() > 0) if use_theory: # Theory values are only calculated where the data is not masked, # so restrict data.x and scale to only those points. # Note: masks merge, so any masked theory points will stay masked, # and the data mask will be added to it. #mtheory = masked_array(theory, data.mask.copy()) theory_x = data.x[data.mask == 0] theory_scale = scale if np.isscalar(scale) else scale[data.mask == 0] mtheory = masked_array(theory) mtheory[~np.isfinite(mtheory)] = masked if view == 'log': mtheory[mtheory <= 0] = masked plt.plot(theory_x, theory_scale*mtheory, '-') all_positive = all_positive and (mtheory > 0).all() some_present = some_present or (mtheory.count() > 0) if limits is not None: plt.ylim(*limits) plt.xscale('linear' if not some_present or non_positive_x else 'log') plt.yscale('log' if some_present and view == 'log' else 'linear') plt.xlabel("$q$/A$^{-1}$") plt.ylabel('$10^8 q^4 I(q)$' if view == 'q4' else '$I(q)$') title = ("data and model" if use_theory and use_data else "data" if use_data else "model") plt.title(title) if use_calc: # Only have use_calc if have use_theory plt.subplot(1, num_plots, 2) qx, qy, Iqxy = Iq_calc plt.pcolormesh(qx, qy[qy > 0], np.log10(Iqxy[qy > 0, :])) plt.xlabel("$q_x$/A$^{-1}$") plt.xlabel("$q_y$/A$^{-1}$") plt.xscale('log') plt.yscale('log') #plt.axis('equal') if use_resid: theory_x = data.x[data.mask == 0] mresid = masked_array(resid) mresid[~np.isfinite(mresid)] = masked some_present = (mresid.count() > 0) if num_plots > 1: plt.subplot(1, num_plots, use_calc + 2) plt.plot(theory_x, mresid, '.') plt.xlabel("$q$/A$^{-1}$") plt.ylabel('residuals') plt.title('(model - Iq)/dIq') plt.xscale('linear' if not some_present or non_positive_x else 'log') plt.yscale('linear')
[docs]@protect def _plot_result_sesans(data, theory, resid, use_data, limits=None): # type: (SesansData, OptArray, OptArray, bool, OptLimits) -> None """ Plot SESANS results. """ import matplotlib.pyplot as plt # type: ignore use_data = use_data and data.y is not None use_theory = theory is not None use_resid = resid is not None num_plots = (use_data or use_theory) + use_resid if use_data or use_theory: is_tof = data.lam is not None and (data.lam != data.lam[0]).any() if num_plots > 1: plt.subplot(1, num_plots, 1) if use_data: if is_tof: plt.errorbar(data.x, np.log(data.y)/(data.lam*data.lam), yerr=data.dy/data.y/(data.lam*data.lam)) else: plt.errorbar(data.x, data.y, yerr=data.dy) if theory is not None: if is_tof: plt.plot(data.x, np.log(theory)/(data.lam*data.lam), '-') else: plt.plot(data.x, theory, '-') if limits is not None: plt.ylim(*limits) plt.xlabel('spin echo length ({})'.format(data._xunit)) if is_tof: plt.ylabel(r'(Log (P/P$_0$))/$\lambda^2$') else: plt.ylabel('polarization (P/P0)') if resid is not None: if num_plots > 1: plt.subplot(1, num_plots, (use_data or use_theory) + 1) plt.plot(data.x, resid, 'x') plt.xlabel('spin echo length ({})'.format(data._xunit)) plt.ylabel('residuals (P/P0)')
[docs]@protect def _plot_result2D(data, theory, resid, view, use_data, limits=None): # type: (Data2D, OptArray, OptArray, str, bool, OptLimits) -> None """ Plot the data and residuals for 2D data. """ import matplotlib.pyplot as plt # type: ignore if view is None: view = 'log' use_data = use_data and data.data is not None use_theory = theory is not None use_resid = resid is not None num_plots = use_data + use_theory + use_resid # Put theory and data on a common colormap scale vmin, vmax = np.inf, -np.inf target = None # type: OptArray if use_data: target = data.data[~data.mask] datamin = target[target > 0].min() if view == 'log' else target.min() datamax = target.max() vmin = min(vmin, datamin) vmax = max(vmax, datamax) if use_theory: theorymin = theory[theory > 0].min() if view == 'log' else theory.min() theorymax = theory.max() vmin = min(vmin, theorymin) vmax = max(vmax, theorymax) # Override data limits from the caller if limits is not None: vmin, vmax = limits # Plot data if use_data: if num_plots > 1: plt.subplot(1, num_plots, 1) _plot_2d_signal(data, target, view=view, vmin=vmin, vmax=vmax) plt.title('data') h = plt.colorbar() h.set_label('$I(q)$') # plot theory if use_theory: if num_plots > 1: plt.subplot(1, num_plots, use_data+1) _plot_2d_signal(data, theory, view=view, vmin=vmin, vmax=vmax) plt.title('theory') h = plt.colorbar() h.set_label(r'$\log_{10}I(q)$' if view == 'log' else r'$q^4 I(q)$' if view == 'q4' else '$I(q)$') # plot resid if use_resid: if num_plots > 1: plt.subplot(1, num_plots, use_data+use_theory+1) _plot_2d_signal(data, resid, view='linear') plt.title('residuals') h = plt.colorbar() h.set_label(r'$\Delta I(q)$')
[docs]@protect def _plot_2d_signal(data, signal, vmin=None, vmax=None, view=None): # type: (Data2D, np.ndarray, Optional[float], Optional[float], str) -> Tuple[float, float] """ Plot the target value for the data. This could be the data itself, the theory calculation, or the residuals. *scale* can be 'log' for log scale data, or 'linear'. """ import matplotlib.pyplot as plt # type: ignore from numpy.ma import masked_array # type: ignore if view is None: view = 'log' image = np.zeros_like(data.qx_data) image[~data.mask] = signal valid = np.isfinite(image) & ~data.mask if view == 'log': valid &= image > 0 if vmin is None: vmin = image[valid].min() if vmax is None: vmax = image[valid].max() image[valid] = np.log10(image[valid]) elif view == 'q4': image[valid] *= (data.qx_data[valid]**2+data.qy_data[valid]**2)**2 if vmin is None: vmin = image[valid].min() if vmax is None: vmax = image[valid].max() else: if vmin is None: vmin = image[valid].min() if vmax is None: vmax = image[valid].max() image[~valid] = 0 #plottable = Iq plottable = masked_array(image, ~valid) # Divide range by 10 to convert from angstroms to nanometers xmin, xmax = min(data.qx_data), max(data.qx_data) ymin, ymax = min(data.qy_data), max(data.qy_data) if view == 'log': vmin_scaled, vmax_scaled = np.log10(vmin), np.log10(vmax) else: vmin_scaled, vmax_scaled = vmin, vmax #nx, ny = len(data.x_bins), len(data.y_bins) _, _, image = _build_matrix(data, plottable) plt.imshow(image, interpolation='nearest', aspect=1, origin='lower', extent=[xmin, xmax, ymin, ymax], vmin=vmin_scaled, vmax=vmax_scaled) plt.xlabel("$q_x$/A$^{-1}$") plt.ylabel("$q_y$/A$^{-1}$") return vmin, vmax
# === The following is modified from sas.sasgui.plottools.PlotPanel
[docs]def _build_matrix(self, plottable): """ Build a matrix for 2d plot from a vector Returns a matrix (image) with ~ square binning Requirement: need 1d array formats of self.data, self.qx_data, and self.qy_data where each one corresponds to z, x, or y axis values """ # No qx or qy given in a vector format if (self.qx_data is None or self.qy_data is None or self.qx_data.ndim != 1 or self.qy_data.ndim != 1): return self.x_bins, self.y_bins, plottable # maximum # of loops to fillup_pixels # otherwise, loop could never stop depending on data max_loop = 1 # get the x and y_bin arrays. x_bins, y_bins = _get_bins(self) # set zero to None #Note: Can not use scipy.interpolate.Rbf: # 'cause too many data points (>10000)<=JHC. # 1d array to use for weighting the data point averaging #when they fall into a same bin. weights_data = np.ones([self.data.size]) # get histogram of ones w/len(data); this will provide #the weights of data on each bins weights, _, _ = np.histogram2d( x=self.qy_data, y=self.qx_data, bins=[y_bins, x_bins], weights=weights_data) # get histogram of data, all points into a bin in a way of summing image, _, _ = np.histogram2d( x=self.qy_data, y=self.qx_data, bins=[y_bins, x_bins], weights=plottable) # Now, normalize the image by weights only for weights>1: # If weight == 1, there is only one data point in the bin so # that no normalization is required. image[weights > 1] = image[weights > 1] / weights[weights > 1] # Set image bins w/o a data point (weight==0) as None (was set to zero # by histogram2d.) image[weights == 0] = None # Fill empty bins with 8 nearest neighbors only when at least #one None point exists loop = 0 # do while loop until all vacant bins are filled up up #to loop = max_loop while (weights == 0).any(): if loop >= max_loop: # this protects never-ending loop break image = _fillup_pixels(image=image, weights=weights) loop += 1 return x_bins, y_bins, image
[docs]def _get_bins(self): """ get bins set x_bins and y_bins into self, 1d arrays of the index with ~ square binning Requirement: need 1d array formats of self.qx_data, and self.qy_data where each one corresponds to x, or y axis values """ # find max and min values of qx and qy xmax = self.qx_data.max() xmin = self.qx_data.min() ymax = self.qy_data.max() ymin = self.qy_data.min() # calculate the range of qx and qy: this way, it is a little # more independent x_size = xmax - xmin y_size = ymax - ymin # estimate the # of pixels on each axes npix_y = int(np.floor(np.sqrt(len(self.qy_data)))) npix_x = int(np.floor(len(self.qy_data) / npix_y)) # bin size: x- & y-directions xstep = x_size / (npix_x - 1) ystep = y_size / (npix_y - 1) # max and min taking account of the bin sizes xmax = xmax + xstep / 2.0 xmin = xmin - xstep / 2.0 ymax = ymax + ystep / 2.0 ymin = ymin - ystep / 2.0 # store x and y bin centers in q space x_bins = np.linspace(xmin, xmax, npix_x) y_bins = np.linspace(ymin, ymax, npix_y) return x_bins, y_bins
[docs]def _fillup_pixels(image=None, weights=None): """ Fill z values of the empty cells of 2d image matrix with the average over up-to next nearest neighbor points :param image: (2d matrix with some zi = None) :return: image (2d array ) :TODO: Find better way to do for-loop below """ # No image matrix given if (image is None or np.ndim(image) != 2 or np.isfinite(image).all() or weights is None): return image # Get bin size in y and x directions len_x, len_y = image.shape[1], image.shape[0] temp_image = np.zeros([len_y, len_x]) weit = np.zeros([len_y, len_x]) # do for-loop for all pixels for n_y in range(len_y): for n_x in range(len_x): # find only null pixels if weights[n_y][n_x] > 0 or np.isfinite(image[n_y][n_x]): continue # find 4 nearest neighbors # check where or not it is at the corner if n_y != 0 and np.isfinite(image[n_y - 1][n_x]): temp_image[n_y][n_x] += image[n_y - 1][n_x] weit[n_y][n_x] += 1 if n_x != 0 and np.isfinite(image[n_y][n_x - 1]): temp_image[n_y][n_x] += image[n_y][n_x - 1] weit[n_y][n_x] += 1 if n_y != len_y - 1 and np.isfinite(image[n_y + 1][n_x]): temp_image[n_y][n_x] += image[n_y + 1][n_x] weit[n_y][n_x] += 1 if n_x != len_x - 1 and np.isfinite(image[n_y][n_x + 1]): temp_image[n_y][n_x] += image[n_y][n_x + 1] weit[n_y][n_x] += 1 # go 4 next nearest neighbors when no non-zero # neighbor exists if (n_y != 0 and n_x != 0 and np.isfinite(image[n_y - 1][n_x - 1])): temp_image[n_y][n_x] += image[n_y - 1][n_x - 1] weit[n_y][n_x] += 1 if (n_y != len_y - 1 and n_x != 0 and np.isfinite(image[n_y + 1][n_x - 1])): temp_image[n_y][n_x] += image[n_y + 1][n_x - 1] weit[n_y][n_x] += 1 if (n_y != len_y and n_x != len_x - 1 and np.isfinite(image[n_y - 1][n_x + 1])): temp_image[n_y][n_x] += image[n_y - 1][n_x + 1] weit[n_y][n_x] += 1 if (n_y != len_y - 1 and n_x != len_x - 1 and np.isfinite(image[n_y + 1][n_x + 1])): temp_image[n_y][n_x] += image[n_y + 1][n_x + 1] weit[n_y][n_x] += 1 # get it normalized ind = (weit > 0) image[ind] = temp_image[ind] / weit[ind] return image
[docs]def demo(): # type: () -> None """ Load and plot a SAS dataset. """ data = load_data('DEC07086.DAT') set_beam_stop(data, 0.004) plot_data(data) import matplotlib.pyplot as plt # type: ignore plt.show()
if __name__ == "__main__": demo()