File: examples.py

package info (click to toggle)
python-pyvista 0.46.5-6
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid
  • size: 178,808 kB
  • sloc: python: 94,599; sh: 216; makefile: 70
file content (798 lines) | stat: -rwxr-xr-x 19,664 bytes parent folder | download | duplicates (4)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
"""Built-in examples that ship with PyVista and do not need to be downloaded.

Examples
--------
>>> from pyvista import examples
>>> mesh = examples.load_ant()
>>> mesh.plot()

"""

from __future__ import annotations

import math
import os
from pathlib import Path

import numpy as np

import pyvista
from pyvista.examples._dataset_loader import _DatasetLoader
from pyvista.examples._dataset_loader import _SingleFileDownloadableDatasetLoader

# get location of this folder and the example files
dir_path = str(Path(os.path.realpath(__file__)).parent)
antfile = str(Path(dir_path) / 'ant.ply')
planefile = str(Path(dir_path) / 'airplane.ply')
hexbeamfile = str(Path(dir_path) / 'hexbeam.vtk')
spherefile = str(Path(dir_path) / 'sphere.ply')
uniformfile = str(Path(dir_path) / 'uniform.vtk')
rectfile = str(Path(dir_path) / 'rectilinear.vtk')
globefile = str(Path(dir_path) / 'globe.vtk')
mapfile = str(Path(dir_path) / '2k_earth_daymap.jpg')
channelsfile = str(Path(dir_path) / 'channels.vti')
logofile = str(Path(dir_path) / 'pyvista_logo.png')
nutfile = str(Path(dir_path) / 'nut.ply')
frogtissuesfile = str(Path(dir_path) / 'frog_tissues.vti')


def load_ant():
    """Load ply ant mesh.

    Returns
    -------
    pyvista.PolyData
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_ant()
    >>> dataset.plot()

    .. seealso::

        :ref:`Ant Dataset <ant_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_ant.load()


_dataset_ant = _SingleFileDownloadableDatasetLoader(antfile, read_func=pyvista.PolyData)  # type: ignore[arg-type]


def load_airplane():
    """Load ply airplane mesh.

    Returns
    -------
    pyvista.PolyData
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_airplane()
    >>> dataset.plot()

    .. seealso::

        :ref:`Airplane Dataset <airplane_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_airplane.load()


_dataset_airplane = _SingleFileDownloadableDatasetLoader(planefile, read_func=pyvista.PolyData)  # type: ignore[arg-type]


def load_sphere():
    """Load sphere ply mesh.

    Returns
    -------
    pyvista.PolyData
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_sphere()
    >>> dataset.plot()

    .. seealso::

        :ref:`Sphere Dataset <sphere_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_sphere.load()


_dataset_sphere = _SingleFileDownloadableDatasetLoader(spherefile, read_func=pyvista.PolyData)  # type: ignore[arg-type]


def load_uniform():
    """Load a sample uniform grid.

    Returns
    -------
    pyvista.ImageData
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_uniform()
    >>> dataset.plot()

    .. seealso::

        :ref:`Uniform Dataset <uniform_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_uniform.load()


_dataset_uniform = _SingleFileDownloadableDatasetLoader(uniformfile, read_func=pyvista.ImageData)  # type: ignore[arg-type]


def load_rectilinear():
    """Load a sample uniform grid.

    Returns
    -------
    pyvista.RectilinearGrid
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_rectilinear()
    >>> dataset.plot()

    .. seealso::

        :ref:`Rectilinear Dataset <rectilinear_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_rectilinear.load()


_dataset_rectilinear = _SingleFileDownloadableDatasetLoader(
    rectfile,
    read_func=pyvista.RectilinearGrid,  # type: ignore[arg-type]
)


def load_hexbeam():
    """Load a sample UnstructuredGrid.

    Returns
    -------
    pyvista.UnstructuredGrid
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_hexbeam()
    >>> dataset.plot()

    .. seealso::

        :ref:`Hexbeam Dataset <hexbeam_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_hexbeam.load()


_dataset_hexbeam = _SingleFileDownloadableDatasetLoader(
    hexbeamfile,
    read_func=pyvista.UnstructuredGrid,  # type: ignore[arg-type]
)


def load_tetbeam():
    """Load a sample UnstructuredGrid containing only tetrahedral cells.

    Returns
    -------
    pyvista.UnstructuredGrid
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_tetbeam()
    >>> dataset.plot()

    .. seealso::

        :ref:`Tetbeam Dataset <tetbeam_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_tetbeam.load()


def _tetbeam_load_func():
    # make the geometry identical to the hexbeam
    xrng = np.linspace(0, 1, 3)
    yrng = np.linspace(0, 1, 3)
    zrng = np.linspace(0, 5, 11)
    grid = pyvista.RectilinearGrid(xrng, yrng, zrng)
    return grid.to_tetrahedra()


_dataset_tetbeam = _DatasetLoader(_tetbeam_load_func)


def load_structured():
    """Load a simple StructuredGrid.

    Returns
    -------
    pyvista.StructuredGrid
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_structured()
    >>> dataset.plot()

    .. seealso::

        :ref:`Structured Dataset <structured_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_structured.load()


def _structured_load_func():
    x = np.arange(-10, 10, 0.25)
    y = np.arange(-10, 10, 0.25)
    x, y = np.meshgrid(x, y)
    r = np.sqrt(x**2 + y**2)
    z = np.sin(r)
    return pyvista.StructuredGrid(x, y, z)


_dataset_structured = _DatasetLoader(_structured_load_func)


def load_globe():
    """Load a globe source.

    Returns
    -------
    pyvista.PolyData
        Globe dataset with earth texture.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_globe()
    >>> texture = examples.load_globe_texture()
    >>> dataset.plot(texture=texture)

    .. seealso::

        :ref:`Globe Dataset <globe_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_globe.load()


_dataset_globe = _SingleFileDownloadableDatasetLoader(globefile, read_func=pyvista.PolyData)  # type: ignore[arg-type]


def load_globe_texture():
    """Load a pyvista.Texture that can be applied to the globe source.

    Returns
    -------
    pyvista.Texture
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_globe_texture()
    >>> dataset.plot()

    .. seealso::

        :ref:`Globe Texture Dataset <globe_texture_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_globe_texture.load()


_dataset_globe_texture = _SingleFileDownloadableDatasetLoader(
    mapfile,
    read_func=pyvista.read_texture,  # type: ignore[arg-type]
)


def load_channels():
    """Load a uniform grid of fluvial channels in the subsurface.

    Returns
    -------
    pyvista.ImageData
        Dataset.

    Examples
    --------
    >>> from pyvista import examples
    >>> dataset = examples.load_channels()
    >>> dataset.plot()

    .. seealso::

        :ref:`Channels Dataset <channels_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_channels.load()


_dataset_channels = _SingleFileDownloadableDatasetLoader(channelsfile)


def load_spline():
    """Load an example spline mesh.

    This example data was created with:

    .. code-block:: python

       >>> import numpy as np
       >>> import pyvista as pv
       >>> theta = np.linspace(-4 * np.pi, 4 * np.pi, 100)
       >>> z = np.linspace(-2, 2, 100)
       >>> r = z**2 + 1
       >>> x = r * np.sin(theta)
       >>> y = r * np.cos(theta)
       >>> points = np.column_stack((x, y, z))
       >>> mesh = pv.Spline(points, 1000)

    Returns
    -------
    pyvista.PolyData
        Spline mesh.

    Examples
    --------
    >>> from pyvista import examples
    >>> spline = examples.load_spline()
    >>> spline.plot()

    .. seealso::

        :ref:`Spline Dataset <spline_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_spline.load()


def _spline_load_func():
    theta = np.linspace(-4 * np.pi, 4 * np.pi, 100)
    z = np.linspace(-2, 2, 100)
    r = z**2 + 1
    x = r * np.sin(theta)
    y = r * np.cos(theta)
    points = np.column_stack((x, y, z))
    return pyvista.Spline(points, 1000)


_dataset_spline = _DatasetLoader(_spline_load_func)


def load_random_hills():
    """Create random hills toy example.

    Uses the parametric random hill function to create hills oriented
    like topography and adds an elevation array.

    This example dataset was created with:

    .. code-block:: python

       >>> mesh = pv.ParametricRandomHills()  # doctest:+SKIP
       >>> mesh = mesh.elevation()  # doctest:+SKIP

    Returns
    -------
    pyvista.PolyData
        Random hills mesh.

    Examples
    --------
    >>> from pyvista import examples
    >>> mesh = examples.load_random_hills()
    >>> mesh.plot()

    .. seealso::

        :ref:`Random Hills Dataset <random_hills_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_random_hills.load()


def _random_hills_load_func():
    mesh = pyvista.ParametricRandomHills()
    return mesh.elevation()


_dataset_random_hills = _DatasetLoader(_random_hills_load_func)


def load_sphere_vectors():
    """Create example sphere with a swirly vector field defined on nodes.

    Returns
    -------
    pyvista.PolyData
        Mesh containing vectors.

    Examples
    --------
    >>> from pyvista import examples
    >>> mesh = examples.load_sphere_vectors()
    >>> mesh.point_data
    pyvista DataSetAttributes
    Association     : POINT
    Active Scalars  : vectors
    Active Vectors  : vectors
    Active Texture  : None
    Active Normals  : Normals
    Contains arrays :
        Normals                 float32    (842, 3)             NORMALS
        vectors                 float32    (842, 3)             VECTORS

    .. seealso::

        :ref:`Sphere Vectors Dataset <sphere_vectors_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_sphere_vectors.load()


def _sphere_vectors_load_func() -> pyvista.PolyData:
    sphere = pyvista.Sphere(radius=math.pi)

    # make cool swirly pattern
    vectors = np.vstack(
        (
            np.sin(sphere.points[:, 0]),
            np.cos(sphere.points[:, 1]),
            np.cos(sphere.points[:, 2]),
        ),
    ).T

    # add and scale
    sphere['vectors'] = vectors * 0.3
    sphere.set_active_vectors('vectors')
    return sphere


_dataset_sphere_vectors = _DatasetLoader(_sphere_vectors_load_func)


def load_explicit_structured(dimensions=(5, 6, 7), spacing=(20, 10, 1)):
    """Load a simple explicit structured grid.

    Parameters
    ----------
    dimensions : tuple(int), optional
        Grid dimensions. Default is (5, 6, 7).
    spacing : tuple(int), optional
        Grid spacing. Default is (20, 10, 1).

    Returns
    -------
    pyvista.ExplicitStructuredGrid
        An explicit structured grid.

    Examples
    --------
    >>> from pyvista import examples
    >>> grid = examples.load_explicit_structured()
    >>> grid.plot(show_edges=True)

    .. seealso::

        :ref:`Explicit Structured Dataset <explicit_structured_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_explicit_structured.load(dimensions=dimensions, spacing=spacing)


def _explicit_structured_load_func(dimensions=(5, 6, 7), spacing=(20, 10, 1)):
    ni, nj, nk = np.asarray(dimensions) - 1
    si, sj, sk = spacing
    xi = np.arange(0.0, (ni + 1) * si, si)
    yi = np.arange(0.0, (nj + 1) * sj, sj)
    zi = np.arange(0.0, (nk + 1) * sk, sk)

    return pyvista.StructuredGrid(
        *np.meshgrid(xi, yi, zi, indexing='ij')
    ).cast_to_explicit_structured_grid()


_dataset_explicit_structured = _DatasetLoader(_explicit_structured_load_func)


def load_nut():
    """Load an example nut mesh.

    Returns
    -------
    pyvista.PolyData
        A sample nut surface dataset.

    Examples
    --------
    Load an example nut and plot with smooth shading.

    >>> from pyvista import examples
    >>> mesh = examples.load_nut()
    >>> mesh.plot(smooth_shading=True, split_sharp_edges=True)

    .. seealso::

        :ref:`Nut Dataset <nut_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_nut.load()


_dataset_nut = _SingleFileDownloadableDatasetLoader(nutfile)


def load_hydrogen_orbital(n=1, l=0, m=0, zoom_fac=1.0):  # noqa: PLR0917
    """Load the hydrogen wave function for a :class:`pyvista.ImageData`.

    This is the solution to the Schrödinger equation for hydrogen
    evaluated in three-dimensional Cartesian space.

    Inspired by `Hydrogen Wave Function
    <http://staff.ustc.edu.cn/~zqj/posts/Hydrogen-Wavefunction/>`_.

    Parameters
    ----------
    n : int, default: 1
        Principal quantum number. Must be a positive integer. This is often
        referred to as the "energy level" or "shell".

    l : int, default: 0
        Azimuthal quantum number. Must be a non-negative integer strictly
        smaller than ``n``. By convention this value is represented by the
        letters s, p, d, f, etc.

    m : int, default: 0
        Magnetic quantum number. Must be an integer ranging from ``-l`` to
        ``l`` (inclusive). This is the orientation of the angular momentum in
        space.

    zoom_fac : float, default: 1.0
        Zoom factor for the electron cloud. Increase this value to focus on the
        center of the electron cloud.

    Returns
    -------
    pyvista.ImageData
        ImageData containing two ``point_data`` arrays:

        * ``'real_wf'`` - Real part of the wave function.
        * ``'wf'`` - Complex wave function.

    Notes
    -----
    This example requires `sympy <https://www.sympy.org/>`_.

    Examples
    --------
    Plot the 3dxy orbital of a hydrogen atom. This corresponds to the quantum
    numbers ``n=3``, ``l=2``, and ``m=-2``.

    >>> from pyvista import examples
    >>> grid = examples.load_hydrogen_orbital(3, 2, -2)
    >>> grid.plot(volume=True, opacity=[1, 0, 1], cmap='magma')

    See :ref:`atomic_orbitals_example` for additional examples using
    this function.

    .. seealso::

        :ref:`Hydrogen Orbital Dataset <hydrogen_orbital_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_hydrogen_orbital.load(n=n, l=l, m=m, zoom_fac=zoom_fac)


def _hydrogen_orbital_load_func(n=1, l=0, m=0, zoom_fac=1.0):  # noqa: PLR0917
    try:
        from sympy import lambdify
        from sympy.abc import phi
        from sympy.abc import r
        from sympy.abc import theta
        from sympy.physics.hydrogen import Psi_nlm
    except ImportError:  # pragma: no cover
        msg = '\n\nInstall sympy to run this example. Run:\n\n    pip install sympy\n'
        raise ImportError(msg) from None

    if n < 1:
        msg = '`n` must be at least 1'
        raise ValueError(msg)
    if l not in range(n):
        msg = f'`l` must be one of: {list(range(n))}'
        raise ValueError(msg)
    if m not in range(-l, l + 1):
        msg = f'`m` must be one of: {list(range(-l, l + 1))}'
        raise ValueError(msg)

    psi = lambdify((r, phi, theta), Psi_nlm(n, l, m, r, phi, theta, 1), 'numpy')

    org = 1.5 * n**2 + 1.0 if n == 1 else 1.5 * n**2 + 10.0

    org /= zoom_fac

    dim = 100
    sp = (org * 2) / (dim - 1)
    grid = pyvista.ImageData(
        dimensions=(dim, dim, dim),
        spacing=(sp, sp, sp),
        origin=(-org, -org, -org),
    )

    r, theta, phi = pyvista.cartesian_to_spherical(grid.x, grid.y, grid.z)
    wfc = psi(r, phi, theta).reshape(grid.dimensions)

    grid['real_wf'] = np.real(wfc.ravel())
    grid['wf'] = wfc.ravel()
    return grid


_dataset_hydrogen_orbital = _DatasetLoader(_hydrogen_orbital_load_func)


def load_logo():
    """Load the PyVista logo as a :class:`pyvista.ImageData`.

    .. note::

        Alternative versions of the logo file are also available from the ``logo``
        directory at https://github.com/pyvista/pyvista/. This includes
        higher-resolution ``.png`` files and a vectorized ``.svg`` version.

    .. versionchanged:: 0.45

        The dimensions of the image is now ``1389 x 592``.
        Previously, it was ``1920 x 718``.

    Returns
    -------
    pyvista.ImageData
        ImageData of the PyVista logo.

    Examples
    --------
    >>> from pyvista import examples
    >>> image = examples.load_logo()
    >>> image.dimensions
    (1389, 592, 1)

    >>> image.plot(cpos='xy', zoom='tight', rgb=True, show_axes=False)

    .. seealso::

        :ref:`Logo Dataset <logo_dataset>`
            See this dataset in the Dataset Gallery for more info.

    """
    return _dataset_logo.load()


_dataset_logo = _SingleFileDownloadableDatasetLoader(logofile)


def load_frog_tissues():
    """Load frog tissues dataset.

    This dataset contains tissue segmentation labels for the frog dataset.

    .. versionadded:: 0.44.0

    Returns
    -------
    pyvista.ImageData
        Dataset.

    Examples
    --------
    Load data

    >>> import numpy as np
    >>> import pyvista as pv
    >>> from pyvista import examples
    >>> data = examples.load_frog_tissues()

    Plot tissue labels as a volume

    First, define plotting parameters

    >>> # Configure colors / color bar
    >>> clim = data.get_data_range()  # Set color bar limits to match data
    >>> cmap = 'glasbey'  # Use a categorical colormap
    >>> categories = True  # Ensure n_colors matches number of labels
    >>> opacity = 'foreground'  # Make foreground opaque, background transparent
    >>> opacity_unit_distance = 1

    Set plotting resolution to half the image's spacing

    >>> res = np.array(data.spacing) / 2

    Define rendering parameters

    >>> mapper = 'gpu'
    >>> shade = True
    >>> ambient = 0.3
    >>> diffuse = 0.6
    >>> specular = 0.5
    >>> specular_power = 40

    Make and show plot

    >>> p = pv.Plotter()
    >>> _ = p.add_volume(
    ...     data,
    ...     clim=clim,
    ...     ambient=ambient,
    ...     shade=shade,
    ...     diffuse=diffuse,
    ...     specular=specular,
    ...     specular_power=specular_power,
    ...     mapper=mapper,
    ...     opacity=opacity,
    ...     opacity_unit_distance=opacity_unit_distance,
    ...     categories=categories,
    ...     cmap=cmap,
    ...     resolution=res,
    ... )
    >>> p.camera_position = 'yx'  # Set camera to provide a dorsal view
    >>> p.show()

    .. seealso::

        :ref:`Frog Tissues Dataset <frog_tissues_dataset>`
            See this dataset in the Dataset Gallery for more info.

        :ref:`Frog Dataset <frog_dataset>`

        :ref:`medical_dataset_gallery`
            Browse other medical datasets.

    """
    return _dataset_frog_tissues.load()


_dataset_frog_tissues = _SingleFileDownloadableDatasetLoader(frogtissuesfile)