code: def get_fnames(name="small_64D"):
      """Provide full paths to example or test datasets.
  
      Parameters
      ----------
      name : str
          the filename/s of which dataset to return, one of:
  
          - 'small_64D' small region of interest nifti,bvecs,bvals 64 directions
          - 'small_101D' small region of interest nifti, bvecs, bvals
            101 directions
          - 'aniso_vox' volume with anisotropic voxel size as Nifti
          - 'fornix' 300 tracks in Trackvis format (from Pittsburgh
            Brain Competition)
          - 'gqi_vectors' the scanner wave vectors needed for a GQI acquisitions
            of 101 directions tested on Siemens 3T Trio
          - 'small_25' small ROI (10x8x2) DTI data (b value 2000, 25 directions)
          - 'test_piesno' slice of N=8, K=14 diffusion data
          - 'reg_c' small 2D image used for validating registration
          - 'reg_o' small 2D image used for validation registration
          - 'cb_2' two vectorized cingulum bundles
  
      Returns
      -------
      fnames : tuple
          filenames for dataset
  
      Examples
      --------
      >>> import numpy as np
      >>> from dipy.io.image import load_nifti
      >>> from dipy.data import get_fnames
      >>> fimg, fbvals, fbvecs = get_fnames('small_101D')
      >>> bvals=np.loadtxt(fbvals)
      >>> bvecs=np.loadtxt(fbvecs).T
      >>> data, affine = load_nifti(fimg)
      >>> data.shape == (6, 10, 10, 102)
      True
      >>> bvals.shape == (102,)
      True
      >>> bvecs.shape == (102, 3)
      True
  
      """
      DATA_DIR = pjoin(op.dirname(__file__), "files")
      if name == "small_64D":
          fbvals = pjoin(DATA_DIR, "small_64D.bval")
          fbvecs = pjoin(DATA_DIR, "small_64D.bvec")
          fimg = pjoin(DATA_DIR, "small_64D.nii")
          return fimg, fbvals, fbvecs
      if name == "55dir_grad":
          fbvals = pjoin(DATA_DIR, "55dir_grad.bval")
          fbvecs = pjoin(DATA_DIR, "55dir_grad.bvec")
          return fbvals, fbvecs
      if name == "small_101D":
          fbvals = pjoin(DATA_DIR, "small_101D.bval")
          fbvecs = pjoin(DATA_DIR, "small_101D.bvec")
          fimg = pjoin(DATA_DIR, "small_101D.nii.gz")
          return fimg, fbvals, fbvecs
      if name == "aniso_vox":
          return pjoin(DATA_DIR, "aniso_vox.nii.gz")
      if name == "ascm_test":
          return pjoin(DATA_DIR, "ascm_out_test.nii.gz")
      if name == "fornix":
          return pjoin(DATA_DIR, "tracks300.trk")
      if name == "gqi_vectors":
          return pjoin(DATA_DIR, "ScannerVectors_GQI101.txt")
      if name == "dsi515btable":
          return pjoin(DATA_DIR, "dsi515_b_table.txt")
      if name == "dsi4169btable":
          return pjoin(DATA_DIR, "dsi4169_b_table.txt")
      if name == "grad514":
          return pjoin(DATA_DIR, "grad_514.txt")
      if name == "small_25":
          fbvals = pjoin(DATA_DIR, "small_25.bval")
          fbvecs = pjoin(DATA_DIR, "small_25.bvec")
          fimg = pjoin(DATA_DIR, "small_25.nii.gz")
          return fimg, fbvals, fbvecs
      if name == "small_25_streamlines":
          fstreamlines = pjoin(DATA_DIR, "EuDX_small_25.trk")
          return fstreamlines
      if name == "S0_10":
          fimg = pjoin(DATA_DIR, "S0_10slices.nii.gz")
          return fimg
      if name == "test_piesno":
          fimg = pjoin(DATA_DIR, "test_piesno.nii.gz")
          return fimg
      if name == "reg_c":
          return pjoin(DATA_DIR, "C.npy")
      if name == "reg_o":
          return pjoin(DATA_DIR, "circle.npy")
      if name == "cb_2":
          return pjoin(DATA_DIR, "cb_2.npz")
      if name == "minimal_bundles":
          return pjoin(DATA_DIR, "minimal_bundles.zip")
      if name == "t1_coronal_slice":
          return pjoin(DATA_DIR, "t1_coronal_slice.npy")
      if name == "t-design":
          N = 45
          return pjoin(DATA_DIR, "tdesign" + str(N) + ".txt")
      if name == "scil_b0":
          files, folder = fetch_scil_b0()
          files = files["datasets_multi-site_all_companies.zip"][2]
          files = [pjoin(folder, f) for f in files]
          return [f for f in files if op.isfile(f)]
      if name == "stanford_hardi":
          files, folder = fetch_stanford_hardi()
          fraw = pjoin(folder, "HARDI150.nii.gz")
          fbval = pjoin(folder, "HARDI150.bval")
          fbvec = pjoin(folder, "HARDI150.bvec")
          return fraw, fbval, fbvec
      if name == "taiwan_ntu_dsi":
          files, folder = fetch_taiwan_ntu_dsi()
          fraw = pjoin(folder, "DSI203.nii.gz")
          fbval = pjoin(folder, "DSI203.bval")
          fbvec = pjoin(folder, "DSI203.bvec")
          return fraw, fbval, fbvec
      if name == "sherbrooke_3shell":
          files, folder = fetch_sherbrooke_3shell()
          fraw = pjoin(folder, "HARDI193.nii.gz")
          fbval = pjoin(folder, "HARDI193.bval")
          fbvec = pjoin(folder, "HARDI193.bvec")
          return fraw, fbval, fbvec
      if name == "isbi2013_2shell":
          files, folder = fetch_isbi2013_2shell()
          fraw = pjoin(folder, "phantom64.nii.gz")
          fbval = pjoin(folder, "phantom64.bval")
          fbvec = pjoin(folder, "phantom64.bvec")
          return fraw, fbval, fbvec
      if name == "stanford_labels":
          files, folder = fetch_stanford_labels()
          return pjoin(folder, "aparc-reduced.nii.gz")
      if name == "syn_data":
          files, folder = fetch_syn_data()
          t1_name = pjoin(folder, "t1.nii.gz")
          b0_name = pjoin(folder, "b0.nii.gz")
          return t1_name, b0_name
      if name == "stanford_t1":
          files, folder = fetch_stanford_t1()
          return pjoin(folder, "t1.nii.gz")
      if name == "stanford_pve_maps":
          files, folder = fetch_stanford_pve_maps()
          f_pve_csf = pjoin(folder, "pve_csf.nii.gz")
          f_pve_gm = pjoin(folder, "pve_gm.nii.gz")
          f_pve_wm = pjoin(folder, "pve_wm.nii.gz")
          return f_pve_csf, f_pve_gm, f_pve_wm
      if name == "ivim":
          files, folder = fetch_ivim()
          fraw = pjoin(folder, "ivim.nii.gz")
          fbval = pjoin(folder, "ivim.bval")
          fbvec = pjoin(folder, "ivim.bvec")
          return fraw, fbval, fbvec
      if name == "tissue_data":
          files, folder = fetch_tissue_data()
          t1_name = pjoin(folder, "t1_brain.nii.gz")
          t1d_name = pjoin(folder, "t1_brain_denoised.nii.gz")
          ap_name = pjoin(folder, "power_map.nii.gz")
          return t1_name, t1d_name, ap_name
      if name == "cfin_multib":
          files, folder = fetch_cfin_multib()
          t1_name = pjoin(folder, "T1.nii")
          fraw = pjoin(
              folder, "__DTI_AX_ep2d_2_5_iso_33d_20141015095334_4.nii"
          )
          fbval = pjoin(
              folder, "__DTI_AX_ep2d_2_5_iso_33d_20141015095334_4.bval"
          )
          fbvec = pjoin(
              folder, "__DTI_AX_ep2d_2_5_iso_33d_20141015095334_4.bvec"
          )
          return fraw, fbval, fbvec, t1_name
      if name == "target_tractrogram_hcp":
          files, folder = fetch_target_tractogram_hcp()
          return pjoin(
              folder,
              "target_tractogram_hcp",
              "hcp_tractogram",
              "streamlines.trk",
          )
      if name == "bundle_atlas_hcp842":
          files, folder = fetch_bundle_atlas_hcp842()
          return get_bundle_atlas_hcp842()
      if name == "qte_lte_pte":
          _, folder = fetch_qte_lte_pte()
          fdata = pjoin(folder, "lte-pte.nii.gz")
          fbval = pjoin(folder, "lte-pte.bval")
          fbvec = pjoin(folder, "lte-pte.bvec")
          fmask = pjoin(folder, "mask.nii.gz")
          return fdata, fbval, fbvec, fmask
      if name == "cti_rat1":
          _, folder = fetch_cti_rat1()
          fdata = pjoin(folder, "Rat1_invivo_cti_data.nii")
          fbval1 = pjoin(folder, "bvals1.bval")
          fbvec1 = pjoin(folder, "bvec1.bvec")
          fbval2 = pjoin(folder, "bvals2.bval")
          fbvec2 = pjoin(folder, "bvec2.bvec")
          fmask = pjoin(folder, "Rat1_mask.nii")
          return fdata, fbval1, fbvec1, fbval2, fbvec2, fmask
      if name == "fury_surface":
          files, folder = fetch_fury_surface()
          surface_name = pjoin(folder, "100307_white_lh.vtk")
          return surface_name
      if name == "histo_resdnn_weights":
          files, folder = fetch_resdnn_weights()
          wraw = pjoin(folder, "resdnn_weights_mri_2018.h5")
          return wraw
      if name == "synb0_default_weights":
          _, folder = fetch_synb0_weights()
          w1 = pjoin(folder, "synb0_default_weights1.h5")
          w2 = pjoin(folder, "synb0_default_weights2.h5")
          w3 = pjoin(folder, "synb0_default_weights3.h5")
          w4 = pjoin(folder, "synb0_default_weights4.h5")
          w5 = pjoin(folder, "synb0_default_weights5.h5")
          return w1, w2, w3, w4, w5
      if name == "synb0_test_data":
          files, folder = fetch_synb0_test()
          input_array = pjoin(folder, "test_input_synb0.npz")
          target_array = pjoin(folder, "test_output_synb0.npz")
          return input_array, target_array
      if name == "evac_default_weights":
          files, folder = fetch_evac_weights()
          weight = pjoin(folder, "evac_default_weights.h5")
          return weight
      if name == "evac_test_data":
          files, folder = fetch_evac_test()
          test_data = pjoin(folder, "evac_test_data.npz")
          return test_data
      if name == "DiB_70_lte_pte_ste":
          _, folder = fetch_DiB_70_lte_pte_ste()
          fdata = pjoin(folder, "DiB_70_lte_pte_ste.nii.gz")
          fbval = pjoin(folder, "bval_DiB_70_lte_pte_ste.bval")
          fbvec = pjoin(folder, "bvec_DiB_70_lte_pte_ste.bvec")
          fmask = pjoin(folder, "DiB_mask.nii.gz")
          return fdata, fbval, fbvec, fmask
      if name == "DiB_217_lte_pte_ste":
          _, folder = fetch_DiB_217_lte_pte_ste()
          fdata_1 = pjoin(folder, "DiB_217_lte_pte_ste_1.nii.gz")
          fdata_2 = pjoin(folder, "DiB_217_lte_pte_ste_2.nii.gz")
          fbval = pjoin(folder, "bval_DiB_217_lte_pte_ste.bval")
          fbvec = pjoin(folder, "bvec_DiB_217_lte_pte_ste.bvec")
          fmask = pjoin(folder, "DiB_mask.nii.gz")
          return fdata_1, fdata_2, fbval, fbvec, fmask
      if name == "ptt_minimal_dataset":
          files, folder = fetch_ptt_minimal_dataset()
          fod_name = pjoin(folder, "ptt_fod.nii")
          seed_coords_name = pjoin(folder, "ptt_seed_coords.txt")
          seed_image_name = pjoin(folder, "ptt_seed_image.nii")
          return fod_name, seed_coords_name, seed_image_name
      if name == "gold_standard_tracks":
          filepath_dix = {}
          files, folder = fetch_gold_standard_io()
          for filename in files:
              filepath_dix[filename] = os.path.join(folder, filename)
  
          with open(filepath_dix["points_data.json"]) as json_file:
              points_data = dict(json.load(json_file))
  
          with open(filepath_dix["streamlines_data.json"]) as json_file:
              streamlines_data = dict(json.load(json_file))
  
          return filepath_dix, points_data, streamlines_data
  
imports: import os
  import contextlib
  import logging
  import json
  import os.path
  from os.path import join
  from hashlib import md5
  from shutil import copyfileobj
  from tqdm.auto import tqdm
  import numpy
  import nibabel
  import tarfile
  import tempfile
  import zipfile
  from dipy.core.gradients import gradient_table, gradient_table_from_gradient_strength_bvecs
  from dipy.io.gradients import read_bvals_bvecs
  from dipy.io.image import load_nifti, load_nifti_data, save_nifti
  from dipy.io.streamline import load_trk
  from dipy.utils.optpkg import optional_package, TripWire
  from urllib.request import urlopen
label_desc: Use image node_id 9 for calling a global function with example usage: get_fnames(name) and returns: fimg,  fbvals,  fbvecs, fbvals,  fbvecs, fimg,  fbvals,  fbvecs, pjoin, pjoin, pjoin, pjoin, pjoin, pjoin, pjoin, fimg,  fbvals,  fbvecs, fstreamlines, fimg, fimg, pjoin, pjoin, pjoin, pjoin, pjoin, pjoin, unknown, fraw,  fbval,  fbvec, fraw,  fbval,  fbvec, fraw,  fbval,  fbvec, fraw,  fbval,  fbvec, pjoin, t1_name,  b0_name, pjoin, f_pve_csf,  f_pve_gm,  f_pve_wm, fraw,  fbval,  fbvec, t1_name,  t1d_name,  ap_name, fraw,  fbval,  fbvec,  t1_name, pjoin, get_bundle_atlas_hcp842, fdata,  fbval,  fbvec,  fmask, fdata,  fbval1,  fbvec1,  fbval2,  fbvec2,  fmask, surface_name, wraw, w1,  w2,  w3,  w4,  w5, input_array,  target_array, weight, test_data, fdata,  fbval,  fbvec,  fmask, fdata_1,  fdata_2,  fbval,  fbvec,  fmask, fod_name,  seed_coords_name,  seed_image_name, filepath_dix,  points_data,  streamlines_data