Exemplo n.º 1
0
def test_img_table_checks():
    # check matching lengths
    with pytest.raises(ValueError):
        _check_list_length_match([''] * 2, [''], "", "")
    # check tables type and that can be loaded
    with pytest.raises(ValueError):
        _check_and_load_tables(['.csv', '.csv'], "")
    with pytest.raises(TypeError):
        _check_and_load_tables([np.array([0]), pd.DataFrame()], "")
    with pytest.raises(ValueError):
        _check_and_load_tables(['.csv', pd.DataFrame()], "")
    # check high level wrapper keeps behavior
    with pytest.raises(ValueError):
        _check_run_tables([''] * 2, [''], "")
    with pytest.raises(ValueError):
        _check_run_tables([''] * 2, ['.csv', '.csv'], "")
    with pytest.raises(TypeError):
        _check_run_tables([''] * 2, [np.array([0]), pd.DataFrame()], "")
    with pytest.raises(ValueError):
        _check_run_tables([''] * 2, ['.csv', pd.DataFrame()], "")
Exemplo n.º 2
0
    def fit(self, run_imgs, events=None, confounds=None,
            design_matrices=None):
        """ Fit the GLM

        For each run:
        1. create design matrix X
        2. do a masker job: fMRI_data -> Y
        3. fit regression to (Y, X)

        Parameters
        ----------
        run_imgs: Niimg-like object or list of Niimg-like objects,
            See http://nilearn.github.io/manipulating_images/input_output.html#inputing-data-file-names-or-image-objects  # noqa:E501
            Data on which the GLM will be fitted. If this is a list,
            the affine is considered the same for all.

        events: pandas Dataframe or string or list of pandas DataFrames or
                   strings

            fMRI events used to build design matrices. One events object
            expected per run_img. Ignored in case designs is not None.
            If string, then a path to a csv file is expected.

        confounds: pandas Dataframe, numpy array or string or
                   list of pandas DataFrames, numpy arays or strings 

            Each column in a DataFrame corresponds to a confound variable
            to be included in the regression model of the respective run_img.
            The number of rows must match the number of volumes in the
            respective run_img. Ignored in case designs is not None.
            If string, then a path to a csv file is expected.

        design_matrices: pandas DataFrame or list of pandas DataFrames,
            Design matrices that will be used to fit the GLM. If given it
            takes precedence over events and confounds.

        """
        # Local import to prevent circular imports
        from nilearn.input_data import NiftiMasker  # noqa

        # Check arguments
        # Check imgs type
        if events is not None:
            _check_events_file_uses_tab_separators(events_files=events)
        if not isinstance(run_imgs, (list, tuple)):
            run_imgs = [run_imgs]
        if design_matrices is None:
            if events is None:
                raise ValueError('events or design matrices must be provided')
            if self.t_r is None:
                raise ValueError('t_r not given to FirstLevelModel object'
                                 ' to compute design from events')
        else:
            design_matrices = _check_run_tables(run_imgs, design_matrices,
                                                'design_matrices')
        # Check that number of events and confound files match number of runs
        # Also check that events and confound files can be loaded as DataFrame
        if events is not None:
            events = _check_run_tables(run_imgs, events, 'events')
        if confounds is not None:
            confounds = _check_run_tables(run_imgs, confounds, 'confounds')

        # Learn the mask
        if self.mask_img is False:
            # We create a dummy mask to preserve functionality of api
            ref_img = check_niimg(run_imgs[0])
            self.mask_img = Nifti1Image(np.ones(ref_img.shape[:3]),
                                        ref_img.affine)
        if not isinstance(self.mask_img, NiftiMasker):
            self.masker_ = NiftiMasker(mask_img=self.mask_img,
                                       smoothing_fwhm=self.smoothing_fwhm,
                                       target_affine=self.target_affine,
                                       standardize=self.standardize,
                                       mask_strategy='epi',
                                       t_r=self.t_r,
                                       memory=self.memory,
                                       verbose=max(0, self.verbose - 2),
                                       target_shape=self.target_shape,
                                       memory_level=self.memory_level
                                       )
            self.masker_.fit(run_imgs[0])
        else:
            if self.mask_img.mask_img_ is None and self.masker_ is None:
                self.masker_ = clone(self.mask_img)
                for param_name in ['target_affine', 'target_shape',
                                   'smoothing_fwhm', 't_r', 'memory',
                                   'memory_level']:
                    our_param = getattr(self, param_name)
                    if our_param is None:
                        continue
                    if getattr(self.masker_, param_name) is not None:
                        warn('Parameter %s of the masker'
                             ' overriden' % param_name)
                    setattr(self.masker_, param_name, our_param)
                self.masker_.fit(run_imgs[0])
            else:
                self.masker_ = self.mask_img

        # For each run fit the model and keep only the regression results.
        self.labels_, self.results_, self.design_matrices_ = [], [], []
        n_runs = len(run_imgs)
        t0 = time.time()
        for run_idx, run_img in enumerate(run_imgs):
            # Report progress
            if self.verbose > 0:
                percent = float(run_idx) / n_runs
                percent = round(percent * 100, 2)
                dt = time.time() - t0
                # We use a max to avoid a division by zero
                if run_idx == 0:
                    remaining = 'go take a coffee, a big one'
                else:
                    remaining = (100. - percent) / max(0.01, percent) * dt
                    remaining = '%i seconds remaining' % remaining

                sys.stderr.write(
                    "Computing run %d out of %d runs (%s)\n"
                    % (run_idx + 1, n_runs, remaining))

            # Build the experimental design for the glm
            run_img = check_niimg(run_img, ensure_ndim=4)
            if design_matrices is None:
                n_scans = get_data(run_img).shape[3]
                if confounds is not None:
                    confounds_matrix = confounds[run_idx].values
                    if confounds_matrix.shape[0] != n_scans:
                        raise ValueError('Rows in confounds does not match'
                                         'n_scans in run_img at index %d'
                                         % (run_idx,))
                    confounds_names = confounds[run_idx].columns.tolist()
                else:
                    confounds_matrix = None
                    confounds_names = None
                start_time = self.slice_time_ref * self.t_r
                end_time = (n_scans - 1 + self.slice_time_ref) * self.t_r
                frame_times = np.linspace(start_time, end_time, n_scans)
                design = make_first_level_design_matrix(frame_times,
                                                        events[run_idx],
                                                        self.hrf_model,
                                                        self.drift_model,
                                                        self.high_pass,
                                                        self.drift_order,
                                                        self.fir_delays,
                                                        confounds_matrix,
                                                        confounds_names,
                                                        self.min_onset
                                                        )
            else:
                design = design_matrices[run_idx]
            self.design_matrices_.append(design)

            # Mask and prepare data for GLM
            if self.verbose > 1:
                t_masking = time.time()
                sys.stderr.write('Starting masker computation \r')

            Y = self.masker_.transform(run_img)
            del run_img  # Delete unmasked image to save memory

            if self.verbose > 1:
                t_masking = time.time() - t_masking
                sys.stderr.write('Masker took %d seconds       \n'
                                 % t_masking)

            if self.signal_scaling:
                Y, _ = mean_scaling(Y, self.scaling_axis)
            if self.memory:
                mem_glm = self.memory.cache(run_glm, ignore=['n_jobs'])
            else:
                mem_glm = run_glm

            # compute GLM
            if self.verbose > 1:
                t_glm = time.time()
                sys.stderr.write('Performing GLM computation\r')
            labels, results = mem_glm(Y, design.values,
                                      noise_model=self.noise_model,
                                      bins=100, n_jobs=self.n_jobs)
            if self.verbose > 1:
                t_glm = time.time() - t_glm
                sys.stderr.write('GLM took %d seconds         \n' % t_glm)

            self.labels_.append(labels)
            # We save memory if inspecting model details is not necessary
            if self.minimize_memory:
                for key in results:
                    results[key] = SimpleRegressionResults(results[key])
            self.results_.append(results)
            del Y

        # Report progress
        if self.verbose > 0:
            sys.stderr.write("\nComputation of %d runs done in %i seconds\n\n"
                             % (n_runs, time.time() - t0))

        return self