sdynpy.core.sdynpy_data.NDDataArray

class NDDataArray(shape, nelements, data_dimension, ordinate_dtype='float64', buffer=None, offset=0, strides=None, order=None)[source]

Bases: SdynpyArray

Generic N-Dimensional data structure

This data structure can contain real or complex data. More specific SDynPy data arrays inherit from this superclass.

__init__()

Methods

`argmax`([reduction])	Returns the index of the maximum ordinate in the data array
`argmin`([reduction])	Returns the index of the minimum ordinate in the data array
`downsample`(factor)	Downsample a signal by keeping only every n-th abscissa/ordinate pair.
`extract_elements`(indices)	Parses elements from the data array specified by the passed indices
`extract_elements_by_abscissa`(min_abscissa, ...)	Extracts elements with abscissa values within the specified range
`from_uff`(unv_data_dict[, squeeze])	Create a data array from a unv dictionary from read_unv
`from_unv`(unv_data_dict[, squeeze])	Create a data array from a unv dictionary from read_unv
`interpolate`(interpolated_abscissa[, kind])	Interpolates the NDDataArray using SciPy's interp1d.
`join`(data_arrays[, increment_abscissa])	Joins several data arrays together by concatenating their ordinates
`load`(filename)	Load in the specified file into a SDynPy array object
`max`([reduction])	Returns the maximum ordinate in the data array
`min`([reduction])	Returns the minimum ordinate in the data array
`plot`([one_axis, subplots_kwargs, plot_kwargs])	Plot the data array
`reshape_to_matrix`()	Reshapes a data array to a matrix with response coordinates along the rows and reference coordinates along the columns
`save`(filename)	Save the array to a numpy file
`to_imat_struct`([Version, SetRecord, ...])	Creates a Matlab structure that can be read the IMAT toolbox.
`to_imat_struct_array`([Version, SetRecord, ...])	Creates a Matlab structure that can be read the IMAT toolbox.
`to_shape_array`([abscissa_values])	Converts an NDDataArray to a ShapeArray
`transform_coordinate_system`(...[, ...])	Performs coordinate system transformations on the data
`validate_common_abscissa`(**allclose_kwargs)	Returns True if all functions have the same abscissa
`zero_pad`([num_samples, update_abscissa, ...])	Add zeros to the beginning or end of a signal

Attributes

`abscissa_spacing`	The spacing of the abscissa in the function.
`data_dimension`	Number of dimensions to the data
`function_type`	Returns the function type of the data array as a FunctionTypes Enum
`idx_by_ab`	AbscissaValueExtractor that can be indexed to extract an abscissa range
`idx_by_el`	AbscissaIndexExtractor that can be indexed to extract specific elements
`num_coordinates`	Number of coordinates defining the data array
`num_elements`	Number of elements in each data array
`reference_coordinate`	CoordinateArray corresponding to the response coordinates
`response_coordinate`	CoordinateArray corresponding to the response coordinates

property abscissa_spacing: The spacing of the abscissa in the function. Returns ValueError if abscissa are not evenly spaced.

argmax(reduction=None, *argmax_args, **argmax_kwargs)[source]

Returns the index of the maximum ordinate in the data array

Parameters

reduction (function, optional) – Optional function to modify the data, e.g. to select maximum of the absolute value. The default is None.
*argmax_args (various) – Additional arguments passed to np.argmax
**argmax_kwargs (various) – Additional keyword arguments passed to np.argmax

Returns

Index of the maximum of the flattened ordinate. Use np.unravel_index with self.ordinate.shape to get the unflattened index.

Return type

int

argmin(reduction=None, *argmin_args, **argmin_kwargs)[source]

Returns the index of the minimum ordinate in the data array

Parameters

reduction (function, optional) – Optional function to modify the data, e.g. to select minimum of the absolute value. The default is None.
*argmin_args (various) – Additional arguments passed to np.argmax
**argmin_kwargs (various) – Additional keyword arguments passed to np.argmax

Returns

Index of the minimum of the flattened ordinate. Use np.unravel_index with self.ordinate.shape to get the unflattened index.

Return type

int

property data_dimension: Number of dimensions to the data

downsample(factor)[source]

Downsample a signal by keeping only every n-th abscissa/ordinate pair.

Parameters: factor (int) – Downsample factor. Only the factor-th abcissa will be kept.
Returns: The downsampled data object
Return type: NDDataArray

extract_elements(indices)[source]

Parses elements from the data array specified by the passed indices

Parameters: indices – Any type of indices into a np.ndarray to select the elements to keep
Returns: Array reduced to specified elements
Return type: NDDataArray

extract_elements_by_abscissa(min_abscissa, max_abscissa)[source]

Extracts elements with abscissa values within the specified range

Parameters

min_abscissa (float) – Minimum abscissa value to keep
max_abscissa (float) – Maximum abscissa value to keep.

Returns

Array reduced to specified elements.

Return type

NDDataArray

static from_uff(unv_data_dict, squeeze=True)

Create a data array from a unv dictionary from read_unv

Parameters

unv_data_dict (dict) – Dictionary containing data from read_unv
squeeze (bool, optional) – Automatically reduce dimension of the read data if possible. The default is True.

Returns

return_functions – Data read from unv

Return type

NDDataArray

static from_unv(unv_data_dict, squeeze=True)[source]

Create a data array from a unv dictionary from read_unv

Parameters

unv_data_dict (dict) – Dictionary containing data from read_unv
squeeze (bool, optional) – Automatically reduce dimension of the read data if possible. The default is True.

Returns

return_functions – Data read from unv

Return type

NDDataArray

property function_type: Returns the function type of the data array as a FunctionTypes Enum

property idx_by_ab: AbscissaValueExtractor that can be indexed to extract an abscissa range

property idx_by_el: AbscissaIndexExtractor that can be indexed to extract specific elements

interpolate(interpolated_abscissa, kind='linear', **kwargs)[source]

Interpolates the NDDataArray using SciPy’s interp1d.

Parameters

interpolated_abscissa (ndarray) – Abscissa values at which to interpolate the function. If multi-dimensional, it will be flattened.
kind (str or int, optional) – Specifies the kind of interpolation as a string or as an integer specifying the order of the spline interpolator to use. The string has to be one of ‘linear’, ‘nearest’, ‘nearest-up’, ‘zero’, ‘slinear’, ‘quadratic’, ‘cubic’, ‘previous’, or ‘next’. ‘zero’, ‘slinear’, ‘quadratic’ and ‘cubic’ refer to a spline interpolation of zeroth, first, second or third order; ‘previous’ and ‘next’ simply return the previous or next value of the point; ‘nearest-up’ and ‘nearest’ differ when interpolating half-integers (e.g. 0.5, 1.5) in that ‘nearest-up’ rounds up and ‘nearest’ rounds down. Default is ‘linear’.
**kwargs – Additional arguments to scipy.interpolate.interp1d.

Returns

Array with interpolated arguments

Return type

NDDataArray

classmethod join(data_arrays, increment_abscissa=True)[source]

Joins several data arrays together by concatenating their ordinates

Parameters

data_arrays (NDDataArray) – Arrays to concatenate
increment_abscissa (bool, optional) – Determines how the abscissa concatenation is handled. If False, the abscissa is left as it was in the original functions. If True, it will be incremented so it is continuous.

Return type

NDDataArray subclass

classmethod load(filename)[source]

Load in the specified file into a SDynPy array object

Parameters: filename (str) – Filename specifying the file to load. If the filename has extension .unv or .uff, it will be loaded as a universal file. Otherwise, it will be loaded as a NumPy file.
Raises: AttributeError – Raised if a unv file is loaded from a class that does not have a from_unv attribute defined.
Returns: SDynpy array of the appropriate type from the loaded file.
Return type: cls

max(reduction=None, *max_args, **max_kwargs)[source]

Returns the maximum ordinate in the data array

Parameters

reduction (function, optional) – Optional function to modify the data, e.g. to select maximum of the absolute value. The default is None.
*max_args (various) – Additional arguments passed to np.max
**max_kwargs (various) – Additional keyword arguments passed to np.max

Returns

Maximum value in the ordinate.

Return type

Value

min(reduction=None, *min_args, **min_kwargs)[source]

Returns the minimum ordinate in the data array

Parameters

reduction (function, optional) – Optional function to modify the data, e.g. to select minimum of the absolute value. The default is None.
*min_args (various) – Additional arguments passed to np.min
**min_kwargs (various) – Additional keyword arguments passed to np.min

Returns

Minimum value in the ordinate.

Return type

Value

property num_coordinates: Number of coordinates defining the data array

property num_elements: Number of elements in each data array

plot(one_axis: bool = True, subplots_kwargs: dict = {}, plot_kwargs: dict = {})[source]

Plot the data array

Parameters

one_axis (bool, optional) – Set to True to plot all data on one axis. Set to False to plot data on multiple subplots. one_axis can also be set to a matplotlib axis to plot data on an existing axis. The default is True.
subplots_kwargs (dict, optional) – Keywords passed to the matplotlib subplots function to create the figure and axes. The default is {}.
plot_kwargs (dict, optional) – Keywords passed to the matplotlib plot function. The default is {}.

Returns

axis – On which the data were plotted

Return type

matplotlib axis or array of axes

property reference_coordinate: CoordinateArray corresponding to the response coordinates

reshape_to_matrix()[source]

Reshapes a data array to a matrix with response coordinates along the rows and reference coordinates along the columns

Returns: output_array – 2D Array of NDDataArray
Return type: Data Aarray

property response_coordinate: CoordinateArray corresponding to the response coordinates

save(filename)[source]

Save the array to a numpy file

Parameters: filename (str) – Filename that the array will be saved to. Will be appended with .npz if not specified in the filename

to_imat_struct(Version=None, SetRecord=None, CreateDate: Optional[datetime] = None, ModifyDate: Optional[datetime] = None, OwnerName=None, AbscissaDataType=None, AbscissaTypeQual=None, AbscissaAxisLab=None, AbscissaUnitsLab=None, OrdNumDataType=None, OrdNumTypeQual=None, OrdDenDataType=None, OrdDenTypeQual=None, OrdinateAxisLab=None, OrdinateUnitsLab=None, ZAxisDataType=None, ZAxisTypeQual=None, ZGeneralValue=None, ZRPMValue=None, ZOrderValue=None, ZTimeValue=None, UserValue1=None, UserValue2=None, UserValue3=None, UserValue4=None, SamplingType=None, WeightingType=None, WindowType=None, AmplitudeUnits=None, Normalization=None, OctaveFormat=None, OctaveAvgType=None, ExpDampingFact=None, PulsesPerRev=None, MeasurementRun=None, LoadCase=None, IRIGTime=None)[source]

Creates a Matlab structure that can be read the IMAT toolbox.

This structure can be read by the IMAT toolbox in Matlab to create an imat_fn object. Note this is generally a faster function than to_imat_struct_array.

Parameters

Version (TYPE, optional) – DESCRIPTION. The default is None.
SetRecord (TYPE, optional) – DESCRIPTION. The default is None.
CreateDate (datetime, optional) – DESCRIPTION. The default is None.
ModifyDate (datetime, optional) – DESCRIPTION. The default is None.
OwnerName (TYPE, optional) – DESCRIPTION. The default is None.
AbscissaDataType (TYPE, optional) – DESCRIPTION. The default is None.
AbscissaTypeQual (TYPE, optional) – DESCRIPTION. The default is None.
AbscissaAxisLab (TYPE, optional) – DESCRIPTION. The default is None.
AbscissaUnitsLab (TYPE, optional) – DESCRIPTION. The default is None.
OrdNumDataType (TYPE, optional) – DESCRIPTION. The default is None.
OrdNumTypeQual (TYPE, optional) – DESCRIPTION. The default is None.
OrdDenDataType (TYPE, optional) – DESCRIPTION. The default is None.
OrdDenTypeQual (TYPE, optional) – DESCRIPTION. The default is None.
OrdinateAxisLab (TYPE, optional) – DESCRIPTION. The default is None.
OrdinateUnitsLab (TYPE, optional) – DESCRIPTION. The default is None.
ZAxisDataType (TYPE, optional) – DESCRIPTION. The default is None.
ZAxisTypeQual (TYPE, optional) – DESCRIPTION. The default is None.
ZGeneralValue (TYPE, optional) – DESCRIPTION. The default is None.
ZRPMValue (TYPE, optional) – DESCRIPTION. The default is None.
ZOrderValue (TYPE, optional) – DESCRIPTION. The default is None.
ZTimeValue (TYPE, optional) – DESCRIPTION. The default is None.
UserValue1 (TYPE, optional) – DESCRIPTION. The default is None.
UserValue2 (TYPE, optional) – DESCRIPTION. The default is None.
UserValue3 (TYPE, optional) – DESCRIPTION. The default is None.
UserValue4 (TYPE, optional) – DESCRIPTION. The default is None.
SamplingType (TYPE, optional) – DESCRIPTION. The default is None.
WeightingType (TYPE, optional) – DESCRIPTION. The default is None.
WindowType (TYPE, optional) – DESCRIPTION. The default is None.
AmplitudeUnits (TYPE, optional) – DESCRIPTION. The default is None.
Normalization (TYPE, optional) – DESCRIPTION. The default is None.
OctaveFormat (TYPE, optional) – DESCRIPTION. The default is None.
OctaveAvgType (TYPE, optional) – DESCRIPTION. The default is None.
ExpDampingFact (TYPE, optional) – DESCRIPTION. The default is None.
PulsesPerRev (TYPE, optional) – DESCRIPTION. The default is None.
MeasurementRun (TYPE, optional) – DESCRIPTION. The default is None.
LoadCase (TYPE, optional) – DESCRIPTION. The default is None.
IRIGTime (TYPE, optional) – DESCRIPTION. The default is None.

Returns

data_dict – DESCRIPTION.

Return type

TYPE

to_imat_struct_array(Version=1, SetRecord=0, CreateDate: Optional[datetime] = None, ModifyDate: Optional[datetime] = None, OwnerName='', AbscissaDataType=SpecificDataType.UNKNOWN, AbscissaTypeQual=TypeQual.TRANSLATION, AbscissaAxisLab='', AbscissaUnitsLab='', OrdNumDataType=SpecificDataType.UNKNOWN, OrdNumTypeQual=TypeQual.TRANSLATION, OrdDenDataType=SpecificDataType.UNKNOWN, OrdDenTypeQual=TypeQual.TRANSLATION, OrdinateAxisLab='', OrdinateUnitsLab='', ZAxisDataType=SpecificDataType.UNKNOWN, ZAxisTypeQual=TypeQual.TRANSLATION, ZGeneralValue=0, ZRPMValue=0, ZOrderValue=0, ZTimeValue=0, UserValue1=0, UserValue2=0, UserValue3=0, UserValue4=0, SamplingType='Dynamic', WeightingType='None', WindowType='None', AmplitudeUnits='Unknown', Normalization='Unknown', OctaveFormat=0, OctaveAvgType='None', ExpDampingFact=0, PulsesPerRev=0, MeasurementRun=0, LoadCase=0, IRIGTime='', verbose=False)[source]

Creates a Matlab structure that can be read the IMAT toolbox.

This structure can be read by the IMAT toolbox in Matlab to create an imat_fn object. Note this is generally a slower function than to_imat_struct.

Parameters

Version (int, optional) – The version number of the function. The default is 1.
SetRecord (int, optional) – The set record of the function. The default is 0.
CreateDate (datetime, optional) – The date that the function was created. The default is Now.
ModifyDate (datetime, optional) – The date that the function was modified. The default is Now.
OwnerName (str, optional) – The owner of the dataset. The default is ‘’.
AbscissaDataType (SpecificDataType, optional) – The type of data associated with the Abscissa of the function. The default is SpecificDataType.UNKNOWN.
AbscissaTypeQual (TypeQual, optional) – The qualifier associated with the abscissa of the function. The default is TypeQual.TRANSLATION.
AbscissaAxisLab (str, optional) – String used to label the abscissa axis. The default is ‘’.
AbscissaUnitsLab (str, optional) – String used to label the units on the abscissa axis. The default is ‘’.
OrdNumDataType (SpecificDataType, optional) – The type of data associated with the numerator of the ordinate of the function. The default is SpecificDataType.UNKNOWN.
OrdNumTypeQual (TypeQual, optional) – The qualifier associated with the numerator of the ordinate of the function. The default is TypeQual.TRANSLATION.
OrdDenDataType (SpecificDataType, optional) – The type of data associated with the denominator of the ordinate of the function. The default is SpecificDataType.UNKNOWN.
OrdDenTypeQual (TypeQual, optional) – The qualifier associated with the denominator of the ordinate of the function. The default is TypeQual.TRANSLATION.
OrdinateAxisLab (str, optional) – String used to label the ordinate axis. The default is ‘’.
OrdinateUnitsLab (TYPE, optional) – String used to label the units on the ordinate axis. The default is ‘’.
ZAxisDataType (TYPE, optional) – DESCRIPTION. The default is SpecificDataType.UNKNOWN.
ZAxisTypeQual (TYPE, optional) – DESCRIPTION. The default is TypeQual.TRANSLATION.
ZGeneralValue (TYPE, optional) – DESCRIPTION. The default is 0.
ZRPMValue (TYPE, optional) – DESCRIPTION. The default is 0.
ZOrderValue (TYPE, optional) – DESCRIPTION. The default is 0.
ZTimeValue (TYPE, optional) – DESCRIPTION. The default is 0.
UserValue1 (TYPE, optional) – DESCRIPTION. The default is 0.
UserValue2 (TYPE, optional) – DESCRIPTION. The default is 0.
UserValue3 (TYPE, optional) – DESCRIPTION. The default is 0.
UserValue4 (TYPE, optional) – DESCRIPTION. The default is 0.
SamplingType (TYPE, optional) – DESCRIPTION. The default is ‘Dynamic’.
WeightingType (TYPE, optional) – DESCRIPTION. The default is ‘None’.
WindowType (TYPE, optional) – DESCRIPTION. The default is ‘None’.
AmplitudeUnits (TYPE, optional) – DESCRIPTION. The default is ‘Unknown’.
Normalization (TYPE, optional) – DESCRIPTION. The default is ‘Unknown’.
OctaveFormat (TYPE, optional) – DESCRIPTION. The default is 0.
OctaveAvgType (TYPE, optional) – DESCRIPTION. The default is ‘None’.
ExpDampingFact (TYPE, optional) – DESCRIPTION. The default is 0.
PulsesPerRev (TYPE, optional) – DESCRIPTION. The default is 0.
MeasurementRun (TYPE, optional) – DESCRIPTION. The default is 0.
LoadCase (TYPE, optional) – DESCRIPTION. The default is 0.
IRIGTime (TYPE, optional) – DESCRIPTION. The default is ‘’.
verbose (TYPE, optional) – DESCRIPTION. The default is False.

Returns

output_struct – A numpy structured array that can be saved to a mat file using scipy.io.savemat.

Return type

np.ndarray

to_shape_array(abscissa_values=None)[source]

Converts an NDDataArray to a ShapeArray

Parameters: abscissa_values (ndarray, optional) – Abscissa values at which the shapes will be created. The default is to create shapes at all abscissa values. If an entry in abscissa_values does not match a value in abscissa, the closest abscissa value will be selected
Raises: ValueError – If the data does not have common abscissa across all functions or if duplicate response coordinates occur in the NDDataArray
Returns: ShapeArray containing the NDDataArray’s ordinate as its shape_matrix
Return type: ShapeArray

transform_coordinate_system(original_geometry, new_geometry, node_id_map=None, rotations=False)[source]

Performs coordinate system transformations on the data

Parameters

original_geometry (Geometry) – The Geometry in which the shapes are currently defined
new_geometry (Geometry) – The Geometry in which the shapes are desired to be defined
node_id_map (id_map, optional) – If the original and new geometries do not have common node ids, an id_map can be specified to map the original geometry node ids to new geometry node ids. The default is None, which means no mapping will occur, and the geometries have common id numbers.
rotations (bool, optional) – If True, also transform rotational degrees of freedom. The default is False.

Returns

A NDDataArray that can now be plotted with the new geometry

Return type

NDDataArray or Subclass

validate_common_abscissa(**allclose_kwargs)[source]

Returns True if all functions have the same abscissa

Parameters: **allclose_kwargs (various) – Arguments to np.allclose to specify tolerances
Returns: True if all functions have the same abscissa
Return type: bool

zero_pad(num_samples=0, update_abscissa=True, left=False, right=True, use_next_fast_len=False)[source]

Add zeros to the beginning or end of a signal

Parameters

num_samples (int, optional) – Number of zeros to add to the function. If not specified, no zeros are added unless use_next_fast_len is True
update_abscissa (bool, optional) – If True, modify the abscissa to keep the same abscissa spacing. The function must have equally spaced abscissa for this to work. If False, the added abscissa will have a value of zero. The default is True.
left (bool, optional) – Add zeros to the left side (beginning) of the function. The default is False. If both left and right are specified, the zeros will be split half on the left and half on the right.
right (bool, optional) – Add zeros to the right side (end) of the function. The default is True. If both left and right are specified, the zeros will be split half on the left and half on the right
use_next_fast_len (bool, optional) – If True, potentially add additional zeros to the value specified by num_samples to allow the total length of the final signal to reach fast values for FFT as specified by scipy.fft.next_fast_len.

Returns

The zero-padded version of the function

Return type

NDDataArray subclass