diff --git a/src/cdtools/datasets/ptycho_2d_dataset.py b/src/cdtools/datasets/ptycho_2d_dataset.py
index e270714..bdf4e60 100644
--- a/src/cdtools/datasets/ptycho_2d_dataset.py
+++ b/src/cdtools/datasets/ptycho_2d_dataset.py
@@ -361,3 +361,89 @@ class Ptycho2DDataset(CDataset):
             self.background = t.nn.functional.pad(self.background, to_pad)
         
 
+    def downsample(self, factor=2):
+        """Downsamples all diffraction patterns by the specified factor
+
+        This is an easy way to shrink the amount of data you need to work with
+        if the speckle size is much larger than the detector pixel size.
+
+        The downsampling factor must be an integer. The size of the output
+        patterns are reduced by the specified factor, with each output pixel
+        equal to the sum of a <factor> x <factor> region of pixels in the
+        input pattern. This summation is done by pytorch.functional.avg_pool2d.
+        
+        Any mask and background data which is stored with the dataset is
+        downsampled with the data. The background is downsampled using the same
+        method as the data. The mask is expanded so that any output pixel
+        containing a masked pixel will be masked.
+        
+        Parameters
+        ----------
+        factor : int
+            Default 2, the factor to downsample by
+
+        """
+        self.patterns = t.nn.functional.avg_pool2d(
+            self.patterns.unsqueeze(0), factor, divisor_override=1)[0]
+        self.mask = t.logical_not(t.nn.functional.max_pool2d(
+            (1-self.mask.to(dtype=t.uint8)).unsqueeze(0).unsqueeze(0),
+            factor
+        )[0,0].to(dtype=t.bool))
+        
+        self.detector_geometry['basis'] = \
+            self.detector_geometry['basis'] * factor
+
+        if self.background is not None:
+            self.background = t.nn.functional.avg_pool2d(
+                self.background.unsqueeze(0).unsqueeze(0),
+                factor,
+                divisor_override=1)[0,0]
+
+
+    def crop_translations(self, roi):
+        """Shrinks the range of translation positions that are analyzed
+        
+        This deletes all diffraction patterns associated with x- and 
+        y-translations that lie outside of a specified rectangular
+        region of interest. In essence, this operation crops the "relative 
+        displacement map" (shown in self.inspect()) down to the region of 
+        interest.
+
+        Parameters:
+        ----------
+        roi : tuple(float, float, float, float)
+            The translation-x and -y coordinates that define the rectangular 
+            region of interest as (in units of meters)
+            (left, right, bottom, top). The definition of these bounds are
+            based on how an image is normally displayed with matplotlib's
+            imshow. The order in which these elements are defined in roi
+            do not matter as long as roi[:2] and roi[2:] correspond with 
+            the x and y coordinates, respectively.
+        """
+        
+        # Pull out the bounds of the ROI, ensuring that left < right and 
+        #   top < bottom
+        x_left, x_right = sorted(roi[:2])
+        y_top, y_bottom = sorted(roi[2:])
+
+        # Create pointers to the x- and y-translation positions in 
+        #   self.translations
+        x = self.translations[:, 0]
+        y = self.translations[:, 1]
+
+        # Go look for all translation values that lie inside of the roi
+        #   and store their indices.
+        inside_roi = (x >= x_left) & (x <= x_right) & (y <= y_bottom) & (y >= y_top)
+
+        # Throw a value error if inside_roi is empty
+        if not t.any(inside_roi):
+            raise ValueError('The roi does not contain any positions from the dataset '
+                             '(i.e., patterns and translations will be empty).'
+                             ' Please redefine the bounds of the roi.')
+
+        # Update patterns and translations
+        self.patterns = self.patterns[inside_roi]
+        self.translations = self.translations[inside_roi]
+        
+        if hasattr(self, 'intensities') and self.intensities is not None:
+            self.intensities = self.intensities[inside_roi]
\ No newline at end of file
diff --git a/src/cdtools/models/base.py b/src/cdtools/models/base.py
index d2de6f7..b31061d 100644
--- a/src/cdtools/models/base.py
+++ b/src/cdtools/models/base.py
@@ -703,11 +703,14 @@ class CDIModel(t.nn.Module):
             A string with basic info on the latest iteration
         """
         if hasattr(self, 'latest_iteration_time'):
-            return 'Epoch ' + str(len(self.loss_history)) + \
-                  ' completed in %0.2f s with loss ' %\
-                  self.latest_iteration_time + str(self.loss_history[-1])
+            epoch = len(self.loss_history)
+            dt = self.latest_iteration_time
+            loss = self.loss_history[-1]
+            msg = f'Epoch {epoch:3d} completed in {dt:0.2f} s with loss {loss:.5e}'
         else:
-            return 'No reconstruction iterations performed yet!'
+            msg = 'No reconstruction iterations performed yet!'
+
+        return msg
 
     # By default, the plot_list is empty
     plot_list = []
diff --git a/src/cdtools/models/bragg_2d_ptycho.py b/src/cdtools/models/bragg_2d_ptycho.py
index 473c35f..bc10ab4 100644
--- a/src/cdtools/models/bragg_2d_ptycho.py
+++ b/src/cdtools/models/bragg_2d_ptycho.py
@@ -79,6 +79,7 @@ class Bragg2DPtycho(CDIModel):
             lens=False,
             units='um',
             dtype=t.float32,
+            obj_view_crop=0,
     ):
 
         # We need the detector geometry
@@ -147,6 +148,19 @@ class Bragg2DPtycho(CDIModel):
         self.probe = t.nn.Parameter(probe_guess / self.probe_norm)
         self.obj = t.nn.Parameter(obj_guess)
 
+        # NOTE: I think it makes sense to protect against obj_view_crop
+        # being zero or below, because there is nothing else to show outside
+        # the object array. No reason to throw an error if, e.g., the user
+        # asks for a big padding which goes outside of the actual object array.
+        # Just show the full array.
+
+        if obj_view_crop > 0:
+            self.obj_view_slice = np.s_[obj_view_crop:-obj_view_crop,
+                                        obj_view_crop:-obj_view_crop]
+        else:
+            self.obj_view_slice = np.s_[:,:]
+
+
         if probe_support is None:
             probe_support = t.ones_like(self.probe[0], dtype=t.bool)
         self.register_buffer('probe_support',
@@ -155,8 +169,8 @@ class Bragg2DPtycho(CDIModel):
 
         if background is None:
             raise NotImplementedError('Issues with this due to probe fourier padding')
-            background = 1e-6 * t.ones(self.probe[0].shape,
-                                       dtype=t.float32)
+            shape = [s//oversampling for s in self.probe[0]]
+            background = 1e-6 * t.ones(shape, dtype=t.float32)
 
         self.background = t.nn.Parameter(background)
 
@@ -190,10 +204,11 @@ class Bragg2DPtycho(CDIModel):
                 tools.propagators.generate_high_NA_k_intensity_map(
                     self.obj_basis,
                     self.get_detector_geometry()['basis'] / oversampling,
-                    self.background.shape,
+                    [oversampling * d for d in self.background.shape],
                     self.get_detector_geometry()['distance'],
                     self.wavelength,dtype=t.float32,
                     lens=lens)
+
             self.register_buffer('k_map',
                                  t.as_tensor(k_map, dtype=dtype))
             self.register_buffer('intensity_map',
@@ -241,6 +256,7 @@ class Bragg2DPtycho(CDIModel):
             correct_tilt=True,
             lens=False,
             obj_padding=200,
+            obj_view_crop=None,
             units='um',
     ):
         wavelength = dataset.wavelength
@@ -311,7 +327,7 @@ class Bragg2DPtycho(CDIModel):
 
 
         obj_size, min_translation = tools.initializers.calc_object_setup(
-            det_shape,
+            [s * oversampling for s in det_shape],
             pix_translations,
             padding=obj_padding,
         )
@@ -353,9 +369,22 @@ class Bragg2DPtycho(CDIModel):
         probe_stack = [0.01 * probe_max * t.rand(probe.shape,dtype=probe.dtype) for i in range(n_modes - 1)]
         probe = t.stack([probe,] + probe_stack)
 
-
         obj = t.exp(1j*(randomize_ang * (t.rand(obj_size)-0.5)))
-                              
+
+        pfc = (probe_fourier_crop if probe_fourier_crop else [0,0])
+        if obj_view_crop is None:
+            obj_view_crop = min(
+                probe.shape[-2] // 2 + pfc[0],
+                probe.shape[-1] // 2 + pfc[1]
+            )
+        if obj_view_crop < 0:
+            obj_view_crop += min(
+                probe.shape[-2] // 2 + pfc[0],
+                probe.shape[-1] // 2 + pfc[1]
+            )
+
+        obj_view_crop += obj_padding
+        
         det_geo = dataset.detector_geometry
 
         translation_offsets = 0 * (t.rand((len(dataset),2)) - 0.5)
@@ -401,6 +430,7 @@ class Bragg2DPtycho(CDIModel):
                    propagate_probe=propagate_probe,
                    correct_tilt=correct_tilt,
                    lens=lens,
+                   obj_view_crop=obj_view_crop,
                    units=units,
                    )
                    
@@ -473,11 +503,13 @@ class Bragg2DPtycho(CDIModel):
 
     
     def measurement(self, wavefields):
-        return tools.measurements.quadratic_background(wavefields,
-                            self.background,
-                            measurement=tools.measurements.incoherent_sum,
-                            saturation=self.saturation,
-                            oversampling=self.oversampling)
+        return tools.measurements.quadratic_background(
+            wavefields,
+            self.background,
+            measurement=tools.measurements.incoherent_sum,
+            saturation=self.saturation,
+            oversampling=self.oversampling,
+        )
 
     
     def loss(self, sim_data, real_data, mask=None):
@@ -566,21 +598,21 @@ class Bragg2DPtycho(CDIModel):
          )),
         ('Object Amplitude, Surface Normal View', 
          lambda self, fig: p.plot_amplitude(
-             self.obj,
+             self.obj[self.obj_view_slice],
              fig=fig,
              basis=self.obj_basis,
              units=self.units,
          )),
         ('Object Phase, Surface Normal View',
          lambda self, fig: p.plot_phase(
-             self.obj,
+             self.obj[self.obj_view_slice],
              fig=fig,
              basis=self.obj_basis,
              units=self.units,
          )),
         ('Object Amplitude, Beam View', 
          lambda self, fig: p.plot_amplitude(
-             self.obj,
+             self.obj[self.obj_view_slice],
              fig=fig,
              basis=self.obj_basis,
              view_basis=beam_basis,
@@ -588,7 +620,7 @@ class Bragg2DPtycho(CDIModel):
          )),
         ('Object Phase, Beam View',
          lambda self, fig: p.plot_phase(
-             self.obj,
+             self.obj[self.obj_view_slice],
              fig=fig,
              basis=self.obj_basis,
              view_basis=beam_basis,
@@ -596,7 +628,7 @@ class Bragg2DPtycho(CDIModel):
          )),
         ('Object Amplitude, Detector View', 
          lambda self, fig: p.plot_amplitude(
-             self.obj,
+             self.obj[self.obj_view_slice],
              fig=fig,
              basis=self.obj_basis,
              view_basis=self.det_basis,
@@ -604,7 +636,7 @@ class Bragg2DPtycho(CDIModel):
          )),
         ('Object Phase, Detector View',
          lambda self, fig: p.plot_phase(
-             self.obj,
+             self.obj[self.obj_view_slice],
              fig=fig,
              basis=self.obj_basis,
              view_basis=self.det_basis,
diff --git a/src/cdtools/models/fancy_ptycho.py b/src/cdtools/models/fancy_ptycho.py
index ce5c9c4..46e7db6 100644
--- a/src/cdtools/models/fancy_ptycho.py
+++ b/src/cdtools/models/fancy_ptycho.py
@@ -103,9 +103,16 @@ class FancyPtycho(CDIModel):
         self.probe = t.nn.Parameter(probe_guess / self.probe_norm)
         self.obj = t.nn.Parameter(obj_guess)
 
-
-        self.obj_view_slice = np.s_[obj_view_crop:-obj_view_crop,
-                                    obj_view_crop:-obj_view_crop]
+        # NOTE: I think it makes sense to protect against obj_view_crop
+        # being zero or below, because there is nothing else to show outside
+        # the object array. No reason to throw an error if, e.g., the user
+        # asks for a big padding which goes outside of the actual object array.
+        # Just show the full array.
+        if obj_view_crop > 0:
+            self.obj_view_slice = np.s_[obj_view_crop:-obj_view_crop,
+                                        obj_view_crop:-obj_view_crop]
+        else:
+            self.obj_view_slice = np.s_[:,:]
         
         # TODO: perhaps not working anymore for fourier cropped probes
         if background is None:
@@ -498,6 +505,7 @@ class FancyPtycho(CDIModel):
             shift_probe=True,
             multiple_modes=True,
             probe_support=self.probe_support)
+        
         return exit_waves
 
 
@@ -515,7 +523,7 @@ class FancyPtycho(CDIModel):
             self.background,
             measurement=tools.measurements.incoherent_sum,
             saturation=self.saturation,
-            oversampling=int(self.oversampling),
+            oversampling=self.oversampling,
             simulate_finite_pixels=self.simulate_finite_pixels,
         )
 
diff --git a/src/cdtools/tools/analysis/analysis.py b/src/cdtools/tools/analysis/analysis.py
index d6f2f78..0fd913e 100644
--- a/src/cdtools/tools/analysis/analysis.py
+++ b/src/cdtools/tools/analysis/analysis.py
@@ -352,8 +352,7 @@ def synthesize_reconstructions(probes, objects, use_probe=False, obj_slice=None,
         else:
             shift = ip.find_shift(synth_obj[obj_slice],obj[obj_slice], resolution=50)
 
-
-        obj = ip.sinc_subpixel_shift(obj,np.array(shift))
+        obj = ip.sinc_subpixel_shift(obj, shift)
 
         if len(probe.shape) == 3:
             probe = t.stack([ip.sinc_subpixel_shift(p,tuple(shift))
diff --git a/src/cdtools/tools/data/data.py b/src/cdtools/tools/data/data.py
index 19e7467..556aa38 100644
--- a/src/cdtools/tools/data/data.py
+++ b/src/cdtools/tools/data/data.py
@@ -134,18 +134,18 @@ def get_sample_info(cxi_file):
             metadata[attr] = np.float32(s1[attr][()])
 
     if 'unit_cell' in s1:
-        metadata['unit_cell'] = np.array(s1['unit_cell']).astype(np.float32)
+        metadata['unit_cell'] = s1['unit_cell'][()].astype(np.float32)
 
 
     if 'geometry_1/orientation' in s1:
-        orient = np.array(s1['geometry_1/orientation']).astype(np.float32)
+        orient = s1['geometry_1/orientation'][()].astype(np.float32)
         xvec = orient[:3] / np.linalg.norm(orient[:3])
         yvec = orient[3:] / np.linalg.norm(orient[3:])
         metadata['orientation'] = np.array([xvec,yvec,
                                             np.cross(xvec,yvec)])
 
     if 'geometry_1/surface_normal' in s1:
-        snorm = np.array(s1['geometry_1/surface_normal']).astype(np.float32)
+        snorm = s1['geometry_1/surface_normal'][()].astype(np.float32)
         xvec = np.cross(np.array([0.,1.,0.]), snorm)
         xvec /= np.linalg.norm(xvec)
         yvec = np.cross(snorm, xvec)
@@ -218,7 +218,7 @@ def get_detector_geometry(cxi_file):
     d1 = i1['detector_1']
 
     if 'detector_1/basis_vectors' in i1:
-        basis_vectors = np.array(d1['basis_vectors'])
+        basis_vectors = d1['basis_vectors'][()]
         if basis_vectors.shape == (2,3):
             basis_vectors = basis_vectors.T
     else:
@@ -244,11 +244,11 @@ def get_detector_geometry(cxi_file):
                                   [-x_pixel_size,0,0]]).transpose()
 
     try:
-        distance = np.float32(d1['distance'])
+        distance = np.float32(d1['distance'][()])
     except:
         distance = None
     try:
-        corner_position = np.array(d1['corner_position'])
+        corner_position = d1['corner_position'][()]
     except:
         corner_position = None
 
@@ -292,7 +292,7 @@ def get_mask(cxi_file):
 
     i1 = cxi_file['entry_1/instrument_1']
     if 'detector_1/mask' in i1:
-        mask = np.array(i1['detector_1/mask']).astype(np.uint32)
+        mask = i1['detector_1/mask'][()].astype(np.uint32)
         mask_on = np.equal(mask,np.uint32(0))
         mask_has_signal = np.equal(mask,np.uint32(0x00001000))
         return np.logical_or(mask_on,mask_has_signal).astype(bool)
@@ -324,7 +324,7 @@ def get_dark(cxi_file):
 
     i1 = cxi_file['entry_1/instrument_1']
     if 'detector_1/data_dark' in i1:
-        darks = np.array(i1['detector_1/data_dark'])
+        darks = i1['detector_1/data_dark'][()]
         dims = tuple(range(len(darks.shape) - 2))
         darks = np.nanmean(darks,axis=dims)
     else:
@@ -426,7 +426,7 @@ def get_shot_to_shot_info(cxi_file, field_name):
     else:
         raise KeyError('Data is not defined within cxi file')
 
-    return np.array(cxi_file[pull_from]).astype(np.float32)
+    return cxi_file[pull_from][()].astype(np.float32)
 
 
 def get_ptycho_translations(cxi_file):
@@ -485,9 +485,9 @@ def add_entry_info(cxi_file, metadata):
     # included in case the cxi spec becomes more permissive
     for key, value in metadata.items():
         if isinstance(value,(str,bytes)):
-            cxi_file['entry_1'][key] = np.string_(value)
+            cxi_file['entry_1'][key] = np.bytes_(value)
         elif isinstance(value, datetime.datetime):
-            cxi_file['entry_1'][key] = np.string_(value.isoformat())
+            cxi_file['entry_1'][key] = np.bytes_(value.isoformat())
         elif isinstance(value, numbers.Number):
             cxi_file['entry_1'][key] = value
         elif isinstance(value, (np.ndarray,list,tuple)):
@@ -525,9 +525,9 @@ def add_sample_info(cxi_file, metadata):
         if key == 'orientation':
             continue # this is a special case
         if isinstance(value,(str,bytes)):
-            s1[key] = np.string_(value)
+            s1[key] = np.bytes_(value)
         elif isinstance(value, datetime.datetime):
-            s1[key] = np.string_(value.isoformat())
+            s1[key] = np.bytes_(value.isoformat())
         elif isinstance(value, numbers.Number):
             s1[key] = value
         elif isinstance(value, (np.ndarray,list,tuple)):
@@ -701,7 +701,7 @@ def add_data(cxi_file, data, axes=None, compression='gzip',
             axes_str = ':'.join(axes)
         else:
             axes_str = str(axes)
-        det1['data'].attrs['axes'] = np.string_(axes_str)
+        det1['data'].attrs['axes'] = np.bytes_(axes_str)
 
         
 def add_shot_to_shot_info(cxi_file, data, field_name):
@@ -851,11 +851,12 @@ def h5_to_nested_dict(h5_file):
     for key in h5_file.keys():
         value = h5_file[key]
         if isinstance(value, h5py.Dataset):
-            arr = np.array(value)
+            arr = value[()]
             if arr.dtype == object:
                 d[key] = arr.ravel()[0].decode('utf-8')
             elif arr.ndim == 0:
-                d[key] = arr.ravel()[0]
+                # TODO is this needed with arr = value[()]?
+                d[key] = arr.ravel()[0] 
             else:
                 d[key] = arr
             
diff --git a/src/cdtools/tools/initializers/initializers.py b/src/cdtools/tools/initializers/initializers.py
index c0385ee..7e727af 100644
--- a/src/cdtools/tools/initializers/initializers.py
+++ b/src/cdtools/tools/initializers/initializers.py
@@ -57,7 +57,7 @@ def exit_wave_geometry(det_basis, det_shape, wavelength, distance, oversampling=
 
     # This method should work for a general parallelogram-shaped detector
     det_shape = det_basis * det_shape.to(t.float32)
-    pinv_basis = t.tensor(np.linalg.pinv(det_shape).transpose()).to(t.float32)
+    pinv_basis = t.linalg.pinv(det_shape).transpose(0,1)
     real_space_basis = pinv_basis * wavelength * distance
 
     return real_space_basis
diff --git a/tests/conftest.py b/tests/conftest.py
index 9eceb0c..ca3a2c7 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -77,28 +77,28 @@ def ptycho_cxi_1():
     expected['entry metadata'] = {}
     e1e = expected['entry metadata']
     e1e['start_time'] = datetime.datetime.now()
-    e1f['start_time'] = np.string_(e1e['start_time'].isoformat())
+    e1f['start_time'] = np.bytes_(e1e['start_time'].isoformat())
     e1e['end_time'] = datetime.datetime.now()
-    e1f['end_time'] = np.string_(e1e['end_time'].isoformat())
+    e1f['end_time'] = np.bytes_(e1e['end_time'].isoformat())
     e1e['experiment_identifier'] = 'Fake Experiment 1'
-    e1f['experiment_identifier'] = np.string_(e1e['experiment_identifier'])
+    e1f['experiment_identifier'] = np.bytes_(e1e['experiment_identifier'])
     e1e['experiment_description'] = 'A fully defined ptychography experiment to test the data loading'
-    e1f['experiment_description'] = np.string_(e1e['experiment_description'])
+    e1f['experiment_description'] = np.bytes_(e1e['experiment_description'])
     e1e['program_name'] = 'cdtools'
-    e1f['program_name'] = np.string_(e1e['program_name'])
+    e1f['program_name'] = np.bytes_(e1e['program_name'])
     e1e['title'] = 'The one experiment we did'
-    e1f['title'] = np.string_(e1e['title'])
+    e1f['title'] = np.bytes_(e1e['title'])
 
     # Set up the sample info
     s1f = e1f.create_group('sample_1')
     expected['sample info'] = {}
     s1e = expected['sample info']
     s1e['name'] = 'Fake Sample'
-    s1f['name'] = np.string_(s1e['name'])
+    s1f['name'] = np.bytes_(s1e['name'])
     s1e['description'] = 'A sample that isn\'t real'
-    s1f['description'] = np.string_(s1e['description'])
+    s1f['description'] = np.bytes_(s1e['description'])
     s1e['unit_cell_group'] = 'P1'
-    s1f['unit_cell_group'] = np.string_(s1e['unit_cell_group'])
+    s1f['unit_cell_group'] = np.bytes_(s1e['unit_cell_group'])
     s1e['concentration'] = np.float32(np.random.rand())
     s1f['concentration'] = s1e['concentration']
     s1e['mass'] = np.float32(np.random.rand())
@@ -151,7 +151,7 @@ def ptycho_cxi_1():
     d1f.create_dataset('data',data=data)
     data1f['data'] = h5py.SoftLink('/entry_1/instrument_1/detector_1/data')
 
-    d1f['data'].attrs['axes'] = np.string_('translation:y:x')
+    d1f['data'].attrs['axes'] = np.bytes_('translation:y:x')
     expected['axes'] = ['translation','y','x']
 
     g1f = s1f.create_group('geometry_1')
@@ -196,7 +196,7 @@ def ptycho_cxi_2():
     expected['entry metadata'] = {}
     e1e = expected['entry metadata']
     e1e['title'] = 'The one experiment we did'
-    e1f['title'] = np.string_(e1e['title'])
+    e1f['title'] = np.bytes_(e1e['title'])
 
     # Set up the sample info
     s1f = e1f.create_group('sample_1')
@@ -277,9 +277,9 @@ def ptycho_cxi_3():
     expected['entry metadata'] = {}
     e1e = expected['entry metadata']
     e1e['start_time'] = datetime.datetime.now()
-    e1f['start_time'] = np.string_(e1e['start_time'].isoformat())
+    e1f['start_time'] = np.bytes_(e1e['start_time'].isoformat())
     e1e['end_time'] = datetime.datetime.now()
-    e1f['end_time'] = np.string_(e1e['end_time'].isoformat())
+    e1f['end_time'] = np.bytes_(e1e['end_time'].isoformat())
 
     # Set up the sample info
     expected['sample info'] = None
@@ -314,7 +314,7 @@ def ptycho_cxi_3():
     expected['data'] = data
     data1f.create_dataset('data',data=data)
 
-    data1f['data'].attrs['axes'] = np.string_('translation:y:x')
+    data1f['data'].attrs['axes'] = np.bytes_('translation:y:x')
     expected['axes'] = ['translation','y','x']
 
     translations = np.arange(300).reshape((100,3)).astype(np.float32)
diff --git a/tests/test_datasets.py b/tests/test_datasets.py
index d1b5f82..9e72fb7 100644
--- a/tests/test_datasets.py
+++ b/tests/test_datasets.py
@@ -4,7 +4,9 @@ import numpy as np
 import torch as t
 import h5py
 import datetime
-
+from copy import deepcopy
+import pytest
+import itertools
 
 #
 # We start by testing the CDataset base class
@@ -276,3 +278,135 @@ def test_Ptycho2DDataset_get_as(ptycho_cxi_1):
         assert t.allclose(pattern.to(device='cpu'),
                           t.tensor(expected['data'][3,:,:]))
 
+
+def test_Ptycho2DDataset_downsample(test_ptycho_cxis):
+    for cxi, expected in test_ptycho_cxis:
+        dataset = Ptycho2DDataset.from_cxi(cxi)
+
+        # First we test the case of downsampling by 2 against some explicit
+        # calculations
+        copied_dataset = deepcopy(dataset)
+        copied_dataset.downsample(2)
+
+        # May start failing if the test datasets are changed to include
+        # a dataset with any dimension not even. That's a problem with the
+        # test, not the code. Sorry! -Abe
+        assert t.allclose(
+            copied_dataset.patterns,
+            dataset.patterns[:,::2,::2] +
+            dataset.patterns[:,1::2,::2] +
+            dataset.patterns[:,::2,1::2] +
+            dataset.patterns[:,1::2,1::2]
+        )
+        
+        assert t.allclose(
+            copied_dataset.mask,
+            t.logical_and(
+                t.logical_and(dataset.mask[::2,::2],
+                              dataset.mask[1::2,::2]),
+                t.logical_and(dataset.mask[::2,1::2],
+                              dataset.mask[1::2,1::2]),
+            )
+        )
+
+
+        
+        if dataset.background is not None:
+            assert t.allclose(
+                copied_dataset.background,
+                dataset.background[::2,::2] +
+                dataset.background[1::2,::2] +
+                dataset.background[::2,1::2] +
+                dataset.background[1::2,1::2]
+        )
+
+        # And then we just test the shape for a few factors, and check that
+        # it doesn't fail on edge cases (e.g. factor=1)
+        for factor in [1, 2, 3]:
+            copied_dataset = deepcopy(dataset)
+            copied_dataset.downsample(factor=factor)
+
+            expected_pattern_shape = np.concatenate(
+                [[dataset.patterns.shape[0]],
+                 np.array(dataset.patterns.shape[-2:]) // factor]
+            )
+
+            assert np.allclose(expected_pattern_shape,
+                               np.array(copied_dataset.patterns.shape))
+            
+            assert np.allclose(np.array(dataset.mask.shape) // factor,
+                               np.array(copied_dataset.mask.shape))
+            
+            if dataset.background is not None:
+                assert np.allclose(np.array(dataset.background.shape) // factor,
+                                   np.array(copied_dataset.background.shape))
+        
+
+def test_Ptycho2DDataset_crop_translations(ptycho_cxi_1):
+    # Grab dataset
+    cxi, expected = ptycho_cxi_1
+    dataset = Ptycho2DDataset.from_cxi(cxi)
+    copied_dataset = deepcopy(dataset)
+
+    # Test 1: Complain when the the bounds of an ROI are correctly defined,
+    #   but it does not contain any sample positions inside of it. The 
+    #   translations in ptycho_cxi_1 ranges from 0m to -300m in both x and y 
+    #   (it looks like a line scan). We select an ROI at (0, -300) which should 
+    #   not contain any translation positions.
+    with pytest.raises(ValueError) as excinfo:
+        copied_dataset.crop_translations(roi=(0,-5,-295,-300))
+    assert('(i.e., patterns and translations will be empty)') in str(excinfo.value)
+
+    # Test 2: Draw an ROI that's centered in the middle of the x/y translation range
+    #   and make sure that the first and last x/y elements in dataset.translate
+    #   contain x_left, x_right, y_top, and y_bottom
+
+    #   Make tuples that will store the x and y positions. This will be used for
+    #   making permutations of the x/y positions in the ROI later.
+    x_left, y_top = dataset.translations[10,:2]
+    x_right, y_bottom = dataset.translations[-11,:2]
+
+    x_permutations = ((x_left, x_right), (x_right, x_left))
+    y_permutations = ((y_top, y_bottom), (y_bottom, y_top))
+    roi_permutations = tuple((x1, x2, y1, y2) for (x1, x2), (y1, y2) in
+                              itertools.product(x_permutations, y_permutations))
+
+    #   Get the dataset
+    copied_dataset.crop_translations(roi=roi_permutations[0])
+
+    #   Execute the actual test
+    assert (copied_dataset.translations[0,0] in x_permutations[0]) and \
+        (copied_dataset.translations[-1,0] in x_permutations[0])
+    
+    assert (copied_dataset.translations[0,1] in y_permutations[0]) and \
+        (copied_dataset.translations[-1,1] in y_permutations[0])
+
+    # Test 3: Check if the shape of dataset.patterns and dataset.translate is correct
+    #   (designed to be 20 fewer rows here)
+    #   In the future, this should include a check for dataset.intensities once
+    #   an appropriate cxi file is set up for conftest.
+    expected_patterns_shape = np.concatenate([[dataset.patterns.shape[0] - 20], 
+                                            dataset.patterns.shape[-2:]])
+    
+    expected_translations_shape = np.concatenate([[dataset.translations.shape[0] - 20], 
+                                                dataset.translations.shape[-1:]])
+
+    assert np.allclose(np.array(copied_dataset.patterns.shape), expected_patterns_shape)
+        
+    assert np.allclose(np.array(copied_dataset.translations.shape), expected_translations_shape)
+
+    # Test 4: Make sure that we always get the same result no matter what order we
+    #   define the left/right and bottom/top values in roi, provided that roi[:2] 
+    #   and roi[2:] correspond with the x and y coordinates, respectively.
+
+    #   Check each permutation
+    for roi in roi_permutations:
+        # Copy the dataset again; dataset will be modified each time crop_translation
+        # is successfully executed.
+        copied_dataset = deepcopy(dataset)
+        copied_dataset.crop_translations(roi=roi)
+
+        # Check if the contents of dataset.patterns and dataset.translate is correct
+        assert t.allclose(copied_dataset.patterns, dataset.patterns[10:-10,:])
+
+        assert t.allclose(copied_dataset.translations, dataset.translations[10:-10,:])
diff --git a/tests/tools/test_data.py b/tests/tools/test_data.py
index 03998dd..bf048e5 100644
--- a/tests/tools/test_data.py
+++ b/tests/tools/test_data.py
@@ -182,11 +182,11 @@ def test_add_detector(tmp_path):
         # Check this directly since we want to make sure it saved
         # the pixel sizes
         d1 = f['entry_1/instrument_1/detector_1']
-        read_basis = np.array(d1['basis_vectors'])
-        read_x_pix = np.float32(d1['x_pixel_size'])
-        read_y_pix = np.float32(d1['y_pixel_size'])
-        read_distance = np.float32(d1['distance'])
-        read_corner = np.array(d1['corner_position'])
+        read_basis = d1['basis_vectors'][()]
+        read_x_pix = d1['x_pixel_size'][()]
+        read_y_pix = d1['y_pixel_size'][()]
+        read_distance = d1['distance'][()]
+        read_corner = d1['corner_position'][()]
 
     assert np.isclose(distance, read_distance)
     assert np.allclose(basis, read_basis)
@@ -232,8 +232,8 @@ def test_add_data(tmp_path):
     with h5py.File(tmp_path / 'test_add_data.cxi','r') as f:
         # Check this directly since we want to make sure it saved
         # it in all the places it should have
-        read_data_1 = np.array(f['entry_1/data_1/data'])
-        read_data_2 = np.array(f['entry_1/instrument_1/detector_1/data'])
+        read_data_1 = f['entry_1/data_1/data'][()]
+        read_data_2 = f['entry_1/instrument_1/detector_1/data'][()]
         read_axes = str(f['entry_1/instrument_1/detector_1/data'].attrs['axes'].decode())
     
     assert np.allclose(fake_data, read_data_1)
@@ -261,9 +261,10 @@ def test_add_shot_to_shot_info(tmp_path):
     with h5py.File(tmp_path / 'test_add_shot_to_shot_info.cxi') as f:
         # Check this directly since we want to make sure it saved
         # it in all the places it should have
-        read_analyzer_1 = np.array(f['entry_1/data_1/analyzer_angle'])
-        read_analyzer_2 = np.array(f['entry_1/instrument_1/detector_1/analyzer_angle'])
-        read_analyzer_3 = np.array(f['entry_1/sample_1/geometry_1/analyzer_angle'])
+        read_analyzer_1 = f['entry_1/data_1/analyzer_angle'][()]
+        read_analyzer_2 = \
+                       f['entry_1/instrument_1/detector_1/analyzer_angle'][()]
+        read_analyzer_3 = f['entry_1/sample_1/geometry_1/analyzer_angle'][()]
 
     assert np.allclose(analyzer, read_analyzer_1)
     assert np.allclose(analyzer, read_analyzer_2)
@@ -280,9 +281,10 @@ def test_add_ptycho_translations(tmp_path):
     with h5py.File(tmp_path / 'test_add_ptycho_translations.cxi','r') as f:
         # Check this directly since we want to make sure it saved
         # it in all the places it should have
-        read_translations_1 = np.array(f['entry_1/data_1/translation'])
-        read_translations_2 = np.array(f['entry_1/instrument_1/detector_1/translation'])
-        read_translations_3 = np.array(f['entry_1/sample_1/geometry_1/translation'])
+        read_translations_1 = f['entry_1/data_1/translation'][()]
+        read_translations_2 = \
+                       f['entry_1/instrument_1/detector_1/translation'][()]
+        read_translations_3 = f['entry_1/sample_1/geometry_1/translation'][()]
 
     assert np.allclose(-translations, read_translations_1)
     assert np.allclose(-translations, read_translations_2)
diff --git a/tests/tools/test_measurements.py b/tests/tools/test_measurements.py
index 78eceb0..bfa06de 100644
--- a/tests/tools/test_measurements.py
+++ b/tests/tools/test_measurements.py
@@ -6,7 +6,7 @@ import numpy as np
 def test_intensity():
     wavefields = t.rand((5,10,10)) + 1j * t.rand((5,10,10))
     epsilon=1e-6
-    np_result = np.abs(t.as_tensor(wavefields))**2 + epsilon
+    np_result = np.abs(wavefields.numpy())**2 + epsilon
     assert t.allclose(measurements.intensity(wavefields,epsilon=epsilon),
                       t.as_tensor(np_result))