sasdata.data_util.manipulations module

Data manipulations for 2D data sets. Using the meta data information, various types of averaging are performed in Q-space

To test this module use: ` cd test PYTHONPATH=../src/ python2  -m sasmanipulations.test.utest_averaging DataInfoTests.test_sectorphi_quarter `

class sasdata.data_util.manipulations.Binning(min_value, max_value, n_bins, base=None)

Bases: object

This class just creates a binning object either linear or log

get_bin_index(value)
Parameters:

value – the value in the binning interval whose bin index should be returned. Must be between min_value and max_value.

The general formula logarithm binning is: bin = floor(N * (log(x) - log(min)) / (log(max) - log(min)))

class sasdata.data_util.manipulations.Boxavg(x_min=0.0, x_max=0.0, y_min=0.0, y_max=0.0)

Bases: Boxavg

class sasdata.data_util.manipulations.Boxcut(x_min=0.0, x_max=0.0, y_min=0.0, y_max=0.0)

Bases: Boxcut

class sasdata.data_util.manipulations.Boxsum(x_min=0.0, x_max=0.0, y_min=0.0, y_max=0.0)

Bases: Boxsum

class sasdata.data_util.manipulations.CircularAverage(r_min=0.0, r_max=0.0, bin_width=0.0005)

Bases: object

Perform circular averaging on 2D data

The data returned is the distribution of counts as a function of Q

class sasdata.data_util.manipulations.Ring(r_min=0.0, r_max=0.0, center_x=0.0, center_y=0.0, nbins=36)

Bases: Ring

Wrapper for new Ring.

property nbins_phi
class sasdata.data_util.manipulations.Ringcut(r_min=0.0, r_max=0.0, center_x=0.0, center_y=0.0)

Bases: Ringcut

class sasdata.data_util.manipulations.SectorPhi(r_min, r_max, phi_min=0, phi_max=6.283185307179586, nbins=20, base=None)

Bases: _Sector

Sector average as a function of phi. I(phi) is return and the data is averaged over Q.

A sector is defined by r_min, r_max, phi_min, phi_max. The number of bin in phi also has to be defined.

class sasdata.data_util.manipulations.SectorQ(r_min, r_max, phi_min=0, phi_max=6.283185307179586, nbins=20, base=None)

Bases: _Sector

Sector average as a function of Q for both wings. setting the _Sector.fold attribute determines whether or not the two sectors are averaged together (folded over) or separate. In the case of separate (not folded), the qs for the “minor wing” are arbitrarily set to a negative value. I(Q) is returned and the data is averaged over phi.

A sector is defined by r_min, r_max, phi_min, phi_max. where r_min, r_max, phi_min, phi_max >0. The number of bin in Q also has to be defined.

class sasdata.data_util.manipulations.Sectorcut(phi_min=0.0, phi_max=3.141592653589793, center_x=0.0, center_y=0.0)

Bases: Sectorcut

class sasdata.data_util.manipulations.SlabX(x_min=0.0, x_max=0.0, y_min=0.0, y_max=0.0, bin_width=0.001, fold=False)

Bases: SlabX

Wrapper for new SlabX.

Old signature:

SlabX(x_min=0, x_max=0, y_min=0, y_max=0, bin_width=0.001, fold=False)

New signature uses nbins; translate bin_width -> nbins using ceil(range/bin_width)

class sasdata.data_util.manipulations.SlabY(x_min=0.0, x_max=0.0, y_min=0.0, y_max=0.0, bin_width=0.001, fold=False)

Bases: SlabY

Wrapper for new SlabY. Same bin_width -> nbins translation as SlabX.

class sasdata.data_util.manipulations.WedgePhi(r_min, r_max, phi_min=0, phi_max=6.283185307179586, center_x=0.0, center_y=0.0, nbins=10)

Bases: WedgePhi

Wrapper for new WedgePhi (behaviour matches legacy WedgePhi expectations).

class sasdata.data_util.manipulations.WedgeQ(r_min, r_max, phi_min=0, phi_max=6.283185307179586, center_x=0.0, center_y=0.0, nbins=10)

Bases: WedgeQ

Wrapper for new WedgeQ (behaviour matches legacy WedgeQ expectations).

sasdata.data_util.manipulations.flip_phi(phi: float) float

Force phi to be within the 0 <= to <= 2pi range by adding or subtracting 2pi as necessary

Returns:

phi in >=0 and <=2Pi

sasdata.data_util.manipulations.get_dq_data(data2d: Data2D) array

Get the dq for resolution averaging The pinholes and det. pix contribution present in both direction of the 2D which must be subtracted when converting to 1D: dq_overlap should be calculated ideally at q = 0. Note This method works on only pinhole geometry. Extrapolate dqx(r) and dqy(phi) at q = 0, and take an average.

sasdata.data_util.manipulations.get_intercept(q: float, q_0: float, q_1: float) float | None

Returns the fraction of the side at which the q-value intercept the pixel, None otherwise. The values returned is the fraction ON THE SIDE OF THE LOWEST Q.

    A           B
+-----------+--------+    <--- pixel size
0                    1
Q_0 -------- Q ----- Q_1   <--- equivalent Q range
if Q_1 > Q_0, A is returned
if Q_1 < Q_0, B is returned
if Q is outside the range of [Q_0, Q_1], None is returned
sasdata.data_util.manipulations.get_pixel_fraction(q_max: float, q_00: float, q_01: float, q_10: float, q_11: float) float

Returns the fraction of the pixel defined by the four corners (q_00, q_01, q_10, q_11) that has q < q_max.:

        q_01                q_11
y=1         +--------------+
            |              |
            |              |
            |              |
y=0         +--------------+
        q_00                q_10

            x=0            x=1
sasdata.data_util.manipulations.get_pixel_fraction_square(x: float, x_min: float, x_max: float) float

Return the fraction of the length from xmin to x.:

    A            B
+-----------+---------+
xmin        x         xmax
Parameters:
  • x – x-value

  • x_min – minimum x for the length considered

  • x_max – minimum x for the length considered

Returns:

(x-xmin)/(xmax-xmin) when xmin < x < xmax

sasdata.data_util.manipulations.get_q_compo(dx: float, dy: float, detector_distance: float, wavelength: float, compo: str | None = None) float

This reduces tiny error at very large q. Implementation of this func is not started yet.<–ToDo

sasdata.data_util.manipulations.position_and_wavelength_to_q(dx: float, dy: float, detector_distance: float, wavelength: float) float
Parameters:
  • dx – x-distance from beam center [mm]

  • dy – y-distance from beam center [mm]

  • detector_distance – sample to detector distance [mm]

  • wavelength – neutron wavelength [nm]

Returns:

q-value at the given position

sasdata.data_util.manipulations.reader2D_converter(data2d: Data2D | None = None) Data2D

convert old 2d format opened by IhorReader or danse_reader to new Data2D format This is mainly used by the Readers

Parameters:

data2d – 2d array of Data2D object

Returns:

1d arrays of Data2D object