Source code for pyvista.utilities.helpers

"""Supporting functions for polydata and grid objects."""

import ctypes
import enum
import logging
import signal
import warnings
from threading import Thread
import threading

import numpy as np
import scooby
import vtk
import vtk.util.numpy_support as nps

import pyvista
from .fileio import from_meshio

class FieldAssociation(enum.Enum):
    """Represents which type of vtk field a scalar or vector array is associated with."""

    ROW = vtk.vtkDataObject.FIELD_ASSOCIATION_ROWS

[docs]def get_vtk_type(typ): """Look up the VTK type for a give python data type. Corrects for string type mapping issues. Return ------ int : the integer type id specified in vtkType.h """ typ = nps.get_vtk_array_type(typ) # This handles a silly string type bug if typ == 3: return 13 return typ
def vtk_bit_array_to_char(vtkarr_bint): """Cast vtk bit array to a char array.""" vtkarr = vtk.vtkCharArray() vtkarr.DeepCopy(vtkarr_bint) return vtkarr def vtk_id_list_to_array(vtk_id_list): """Convert a vtkIdList to a NumPy array.""" return np.array([vtk_id_list.GetId(i) for i in range(vtk_id_list.GetNumberOfIds())])
[docs]def convert_string_array(arr, name=None): """Convert a numpy array of strings to a vtkStringArray or vice versa. Note that this is terribly inefficient - inefficient support is better than no support :). If you have ideas on how to make this faster, please consider opening a pull request. """ if isinstance(arr, np.ndarray): vtkarr = vtk.vtkStringArray() ########### OPTIMIZE ########### for val in arr: vtkarr.InsertNextValue(val) ################################ if isinstance(name, str): vtkarr.SetName(name) return vtkarr # Otherwise it is a vtk array and needs to be converted back to numpy ############### OPTIMIZE ############### nvalues = arr.GetNumberOfValues() return np.array([arr.GetValue(i) for i in range(nvalues)], dtype='|U')
######################################## def convert_array(arr, name=None, deep=0, array_type=None): """Convert a NumPy array to a vtkDataArray or vice versa. Parameters ----------- arr : ndarray or vtkDataArry A numpy array or vtkDataArry to convert name : str The name of the data array for VTK deep : bool if input is numpy array then deep copy values Return ------ vtkDataArray, ndarray, or DataFrame: the converted array (if input is a NumPy ndaray then returns ``vtkDataArray`` or is input is ``vtkDataArray`` then returns NumPy ``ndarray``). If pdf==True and the input is ``vtkDataArry``, return a pandas DataFrame. """ if arr is None: return if isinstance(arr, np.ndarray): if arr.dtype is np.dtype('O'): arr = arr.astype('|S') arr = np.ascontiguousarray(arr) if arr.dtype.type in (np.str_, np.bytes_): # This handles strings vtk_data = convert_string_array(arr) else: # This will handle numerical data arr = np.ascontiguousarray(arr) vtk_data = nps.numpy_to_vtk(num_array=arr, deep=deep, array_type=array_type) if isinstance(name, str): vtk_data.SetName(name) return vtk_data # Otherwise input must be a vtkDataArray if not isinstance(arr, (vtk.vtkDataArray, vtk.vtkBitArray, vtk.vtkStringArray)): raise TypeError('Invalid input array type ({}).'.format(type(arr))) # Handle booleans if isinstance(arr, vtk.vtkBitArray): arr = vtk_bit_array_to_char(arr) # Handle string arrays if isinstance(arr, vtk.vtkStringArray): return convert_string_array(arr) # Convert from vtkDataArry to NumPy return nps.vtk_to_numpy(arr) def is_pyvista_dataset(obj): """Return True if the Object is a PyVista wrapped dataset.""" return isinstance(obj, (pyvista.Common, pyvista.MultiBlock)) def point_array(mesh, name): """Return point array of a vtk object.""" vtkarr = mesh.GetPointData().GetAbstractArray(name) return convert_array(vtkarr) def point_scalar(mesh, name): """Return point array of a vtk object. DEPRECATED: please use `point_array` instead. """ warnings.warn("DEPRECATED: please use `point_array` instead.") return point_array(mesh, name) def field_array(mesh, name): """Return field array of a vtk object.""" vtkarr = mesh.GetFieldData().GetAbstractArray(name) return convert_array(vtkarr) def field_scalar(mesh, name): """Return field array of a vtk object. DEPRECATED: please use `field_array` instead. """ warnings.warn("DEPRECATED: please use `field_array` instead.") return field_array(mesh, name) def cell_array(mesh, name): """Return cell array of a vtk object.""" vtkarr = mesh.GetCellData().GetAbstractArray(name) return convert_array(vtkarr) def cell_scalar(mesh, name): """Return cell array of a vtk object. DEPRECATED: please use `cell_array` instead. """ warnings.warn("DEPRECATED: please use `cell_array` instead.") return cell_array(mesh, name) def row_array(data_object, name): """Return row array of a vtk object.""" vtkarr = data_object.GetRowData().GetAbstractArray(name) return convert_array(vtkarr) def parse_field_choice(field): """Return the id of the given field.""" if isinstance(field, str): field = field.strip().lower() if field in ['cell', 'c', 'cells']: field = FieldAssociation.CELL elif field in ['point', 'p', 'points']: field = FieldAssociation.POINT elif field in ['field', 'f', 'fields']: field = FieldAssociation.NONE elif field in ['row', 'r',]: field = FieldAssociation.ROW else: raise ValueError('Data field ({}) not supported.'.format(field)) elif isinstance(field, FieldAssociation): pass else: raise ValueError('Data field ({}) not supported.'.format(field)) return field def get_array(mesh, name, preference='cell', info=False, err=False): """Search point, cell and field data for an array. Parameters ---------- name : str The name of the array to get the range. preference : str, optional When scalars is specified, this is the preferred array type to search for in the dataset. Must be either ``'point'``, ``'cell'``, or ``'field'`` info : bool Return info about the array rather than the array itself. err : bool Boolean to control whether to throw an error if array is not present. """ if isinstance(mesh, vtk.vtkTable): arr = row_array(mesh, name) if arr is None and err: raise KeyError('Data array ({}) not present in this dataset.'.format(name)) field = FieldAssociation.ROW if info: return arr, field return arr parr = point_array(mesh, name) carr = cell_array(mesh, name) farr = field_array(mesh, name) preference = parse_field_choice(preference) if np.sum([parr is not None, carr is not None, farr is not None]) > 1: if preference == FieldAssociation.CELL: if info: return carr, FieldAssociation.CELL else: return carr elif preference == FieldAssociation.POINT: if info: return parr, FieldAssociation.POINT else: return parr elif preference == FieldAssociation.NONE: if info: return farr, FieldAssociation.NONE else: return farr else: raise ValueError('Data field ({}) not supported.'.format(preference)) arr = None field = None if parr is not None: arr = parr field = FieldAssociation.POINT elif carr is not None: arr = carr field = FieldAssociation.CELL elif farr is not None: arr = farr field = FieldAssociation.NONE elif err: raise KeyError('Data array ({}) not present in this dataset.'.format(name)) if info: return arr, field return arr def vtk_points(points, deep=True): """Convert numpy points to a vtkPoints object.""" if not points.flags['C_CONTIGUOUS']: points = np.ascontiguousarray(points) vtkpts = vtk.vtkPoints() vtkpts.SetData(nps.numpy_to_vtk(points, deep=deep)) return vtkpts def line_segments_from_points(points): """Generate non-connected line segments from points. Assumes points are ordered as line segments and an even number of points are Parameters ---------- points : np.ndarray Points representing line segments. An even number must be given as every two vertices represent a single line segment. For example, two line segments would be represented as: np.array([[0, 0, 0], [1, 0, 0], [1, 0, 0], [1, 1, 0]]) Returns ------- lines : pyvista.PolyData PolyData with lines and cells. Examples -------- This example plots two line segments at right angles to each other line. >>> import pyvista >>> import numpy as np >>> points = np.array([[0, 0, 0], [1, 0, 0], [1, 0, 0], [1, 1, 0]]) >>> lines = pyvista.lines_from_points(points) >>> lines.plot() # doctest:+SKIP """ if len(points) % 2 != 0: raise ValueError("An even number of points must be given to define each segment.") # Assuming ordered points, create array defining line order n_points = len(points) n_lines = n_points // 2 lines = np.c_[(2 * np.ones(n_lines, np.int_), np.arange(0, n_points-1, step=2), np.arange(1, n_points+1, step=2))] poly = pyvista.PolyData() poly.points = points poly.lines = lines return poly def lines_from_points(points, close=False): """Make a connected line set given an array of points. Parameters ---------- points : np.ndarray Points representing the vertices of the connected segments. For example, two line segments would be represented as: np.array([[0, 0, 0], [1, 0, 0], [1, 1, 0]]) close : bool, optional If True, close the line segments into a loop Return ------ lines : pyvista.PolyData PolyData with lines and cells. """ poly = pyvista.PolyData() poly.points = points cells = np.full((len(points)-1, 3), 2, dtype=np.int_) cells[:, 1] = np.arange(0, len(points)-1, dtype=np.int_) cells[:, 2] = np.arange(1, len(points), dtype=np.int_) if close: cells = np.append(cells, [[2, len(points)-1, 0],], axis=0) poly.lines = cells return poly def vector_poly_data(orig, vec): """Create a vtkPolyData object composed of vectors.""" # shape, dimension checking if not isinstance(orig, np.ndarray): orig = np.asarray(orig) if not isinstance(vec, np.ndarray): vec = np.asarray(vec) if orig.ndim != 2: orig = orig.reshape((-1, 3)) elif orig.shape[1] != 3: raise ValueError('orig array must be 3D') if vec.ndim != 2: vec = vec.reshape((-1, 3)) elif vec.shape[1] != 3: raise ValueError('vec array must be 3D') # Create vtk points and cells objects vpts = vtk.vtkPoints() vpts.SetData(nps.numpy_to_vtk(np.ascontiguousarray(orig), deep=True)) npts = orig.shape[0] cells = np.empty((npts, 2), dtype=pyvista.ID_TYPE) cells[:, 0] = 1 cells[:, 1] = np.arange(npts, dtype=pyvista.ID_TYPE) vcells = pyvista.utilities.cells.CellArray(cells, npts) # Create vtkPolyData object pdata = vtk.vtkPolyData() pdata.SetPoints(vpts) pdata.SetVerts(vcells) # Add vectors to polydata name = 'vectors' vtkfloat = nps.numpy_to_vtk(np.ascontiguousarray(vec), deep=True) vtkfloat.SetName(name) pdata.GetPointData().AddArray(vtkfloat) pdata.GetPointData().SetActiveVectors(name) # Add magnitude of vectors to polydata name = 'mag' scalars = (vec * vec).sum(1)**0.5 vtkfloat = nps.numpy_to_vtk(np.ascontiguousarray(scalars), deep=True) vtkfloat.SetName(name) pdata.GetPointData().AddArray(vtkfloat) pdata.GetPointData().SetActiveScalars(name) return pyvista.PolyData(pdata) def trans_from_matrix(matrix): """Convert a vtk matrix to a numpy.ndarray.""" t = np.zeros((4, 4)) for i in range(4): for j in range(4): t[i, j] = matrix.GetElement(i, j) return t def is_meshio_mesh(mesh): """Test if passed object is instance of ``meshio.Mesh``.""" try: import meshio return isinstance(mesh, meshio.Mesh) except ImportError: return False def wrap(vtkdataset): """Wrap any given VTK data object to its appropriate PyVista data object. Other formats that are supported include: * 2D :class:`numpy.ndarray` of XYZ vertices * 3D :class:`numpy.ndarray` representing a volume. Values will be scalars. """ wrappers = { 'vtkUnstructuredGrid': pyvista.UnstructuredGrid, 'vtkRectilinearGrid': pyvista.RectilinearGrid, 'vtkStructuredGrid': pyvista.StructuredGrid, 'vtkPolyData': pyvista.PolyData, 'vtkImageData': pyvista.UniformGrid, 'vtkStructuredPoints': pyvista.UniformGrid, 'vtkMultiBlockDataSet': pyvista.MultiBlock, 'vtkTable': pyvista.Table, # 'vtkParametricSpline': pyvista.Spline, } # Otherwise, we assume a VTK data object was passed if hasattr(vtkdataset, 'GetClassName'): key = vtkdataset.GetClassName() elif vtkdataset is None: return None elif isinstance(vtkdataset, np.ndarray): if vtkdataset.ndim == 1 and vtkdataset.shape[0] == 3: return pyvista.PolyData(vtkdataset) if vtkdataset.ndim > 1 and vtkdataset.ndim < 3 and vtkdataset.shape[1] == 3: return pyvista.PolyData(vtkdataset) elif vtkdataset.ndim == 3: mesh = pyvista.UniformGrid(vtkdataset.shape) mesh['values'] = vtkdataset.ravel(order='F') mesh.active_scalars_name = 'values' return mesh else: print(vtkdataset.shape, vtkdataset) raise NotImplementedError('NumPy array could not be converted to PyVista.') elif is_meshio_mesh(vtkdataset): return from_meshio(vtkdataset) else: raise NotImplementedError('Type ({}) not able to be wrapped into a PyVista mesh.'.format(type(vtkdataset))) try: wrapped = wrappers[key](vtkdataset) except KeyError: logging.warning('VTK data type ({}) is not currently supported by pyvista.'.format(key)) return vtkdataset # if not supported just passes the VTK data object return wrapped def image_to_texture(image): """Convert ``vtkImageData`` (:class:`pyvista.UniformGrid`) to a ``vtkTexture``.""" return pyvista.Texture(image) def numpy_to_texture(image): """Convert a NumPy image array to a vtk.vtkTexture.""" if not isinstance(image, np.ndarray): raise TypeError('Unknown input type ({})'.format(type(image))) return pyvista.Texture(image) def is_inside_bounds(point, bounds): """Check if a point is inside a set of bounds. This is implemented through recursion so that this is N-dimensional. """ if isinstance(point, (int, float)): point = [point] if isinstance(point, (np.ndarray, and not isinstance(point, collections.deque): if len(bounds) < 2 * len(point) or len(bounds) % 2 != 0: raise ValueError('Bounds mismatch point dimensionality') point = collections.deque(point) bounds = collections.deque(bounds) return is_inside_bounds(point, bounds) if not isinstance(point, collections.deque): raise TypeError('Unknown input data type ({}).'.format(type(point))) if len(point) < 1: return True p = point.popleft() lower, upper = bounds.popleft(), bounds.popleft() if lower <= p <= upper: return is_inside_bounds(point, bounds) return False def fit_plane_to_points(points, return_meta=False): """Fit a plane to a set of points. Parameters ---------- points : np.ndarray Size n by 3 array of points to fit a plane through return_meta : bool If true, also returns the center and normal used to generate the plane """ data = np.array(points) center = data.mean(axis=0) result = np.linalg.svd(data - center) normal = np.cross(result[2][0], result[2][1]) plane = pyvista.Plane(center=center, direction=normal) if return_meta: return plane, center, normal return plane def raise_not_matching(scalars, mesh): """Raise exception about inconsistencies.""" if isinstance(mesh, vtk.vtkTable): raise ValueError('Number of scalars ({})'.format(scalars.size) + 'must match number of rows ' + '({}).'.format(mesh.n_rows) ) raise ValueError('Number of scalars ({}) '.format(scalars.size) + 'must match either the number of points ' + '({}) '.format(mesh.n_points) + 'or the number of cells ' + '({}). '.format(mesh.n_cells) ) def generate_plane(normal, origin): """Return a vtk.vtkPlane.""" plane = vtk.vtkPlane() # NORMAL MUST HAVE MAGNITUDE OF 1 normal = normal / np.linalg.norm(normal) plane.SetNormal(normal) plane.SetOrigin(origin) return plane def generate_report(additional=None, ncol=3, text_width=54, sort=False): """Generate a report. DEPRECATED: Please use :class:`pyvista.Report` instead. """ logging.warning('DEPRECATED: Please use `pyvista.Report` instead.') core = ['pyvista', 'vtk', 'numpy', 'imageio', 'appdirs', 'scooby'] optional = ['matplotlib', 'PyQt5', 'IPython', 'colorcet', 'cmocean'] report = scooby.Report(core=core, optional=optional, additional=additional, ncol=ncol, text_width=text_width, sort=sort) return report def try_callback(func, *args): """Wrap a given callback in a try statement.""" try: func(*args) except Exception as e: logging.warning('Encountered issue in callback: {}'.format(e)) return def check_depth_peeling(number_of_peels=100, occlusion_ratio=0.0): """Check if depth peeling is available. Attempts to use depth peeling to see if it is available for the current environment. Returns ``True`` if depth peeling is available and has been successfully leveraged, otherwise ``False``. """ # Try Depth Peeling with a basic scene source = vtk.vtkSphereSource() mapper = vtk.vtkPolyDataMapper() mapper.SetInputConnection(source.GetOutputPort()) actor = vtk.vtkActor() actor.SetMapper(mapper) # requires opacity < 1 actor.GetProperty().SetOpacity(0.5) renderer = vtk.vtkRenderer() renderWindow = vtk.vtkRenderWindow() renderWindow.AddRenderer(renderer) renderWindow.SetOffScreenRendering(True) renderWindow.SetAlphaBitPlanes(True) renderWindow.SetMultiSamples(0) renderer.AddActor(actor) renderer.SetUseDepthPeeling(True) renderer.SetMaximumNumberOfPeels(number_of_peels) renderer.SetOcclusionRatio(occlusion_ratio) renderWindow.Render() return renderer.GetLastRenderingUsedDepthPeeling() == 1 def threaded(fn): """Call a function using a thread.""" def wrapper(*args, **kwargs): thread = Thread(target=fn, args=args, kwargs=kwargs) thread.start() return thread return wrapper class conditional_decorator: """Conditional decorator for methods.""" def __init__(self, dec, condition): """Initialize.""" self.decorator = dec self.condition = condition def __call__(self, func): """Call the decorated function if condition is matched.""" if not self.condition: # Return the function unchanged, not decorated. return func return self.decorator(func) class ProgressMonitor(): """A standard class for monitoring the progress of a VTK algorithm. This must be use in a ``with`` context and it will block keyboard interrupts from happening until the exit event as interrupts will crash the kernel if the VTK algorithm is still executing. """ def __init__(self, algorithm, message="", scaling=100): """Initialize observer.""" try: from tqdm import tqdm except ImportError: raise ImportError("Please install `tqdm` to monitor algorithms.") self.event_type = vtk.vtkCommand.ProgressEvent self.progress = 0.0 self._last_progress = self.progress self.algorithm = algorithm self.message = message self._interrupt_signal_received = False self._old_progress = 0 self._old_handler = None self._progress_bar = None def handler(self, sig, frame): """Pass signal to custom interrupt handler.""" self._interrupt_signal_received = (sig, frame) logging.debug('SIGINT received. Delaying KeyboardInterrupt until ' 'VTK algorithm finishes.') def __call__(self, obj, event, *args): """Call progress update callback. On an event occurrence, this function executes. """ if self._interrupt_signal_received: obj.AbortExecuteOn() else: progress = obj.GetProgress() step = progress - self._old_progress self._progress_bar.update(step) self._old_progress = progress def __enter__(self): """Enter event for ``with`` context.""" from tqdm import tqdm # check if in main thread if threading.current_thread().__class__.__name__ == '_MainThread': self._old_handler = signal.signal(signal.SIGINT, self.handler) self._progress_bar = tqdm(total=1, leave=True, bar_format='{l_bar}{bar}[{elapsed}<{remaining}]') self._progress_bar.set_description(self.message) self.algorithm.AddObserver(self.event_type, self) return self._progress_bar def __exit__(self, type, value, traceback): """Exit event for ``with`` context.""" = 1 self._progress_bar.refresh() self._progress_bar.close() self.algorithm.RemoveObservers(self.event_type) if threading.current_thread().__class__.__name__ == '_MainThread': signal.signal(signal.SIGINT, self._old_handler) def abstract_class(cls_): """Decorate a class, overriding __new__. Preventing a class from being instantiated similar to abc.ABCMeta but does not require an abstract method. """ def __new__(cls, *args, **kwargs): if cls is cls_: raise TypeError('{} is an abstract class and may not be instantiated.' .format(cls.__name__)) return object.__new__(cls) cls_.__new__ = __new__ return cls_