Note
This page is a reference documentation. It only explains the class signature, and not how to use it. Please refer to the user guide for the big picture.
nilearn.maskers.NiftiLabelsMasker#
- class nilearn.maskers.NiftiLabelsMasker(labels_img, labels=None, background_label=0, mask_img=None, smoothing_fwhm=None, standardize=False, standardize_confounds=True, high_variance_confounds=False, detrend=False, low_pass=None, high_pass=None, t_r=None, dtype=None, resampling_target='data', memory=Memory(location=None), memory_level=1, verbose=0, strategy='mean', reports=True)[source]#
Class for masking of Niimg-like objects.
NiftiLabelsMasker is useful when data from non-overlapping volumes should be extracted (contrarily to
nilearn.maskers.NiftiMapsMasker
). Use case: Summarize brain signals from clusters that were obtained by prior K-means or Ward clustering.- Parameters
- labels_imgNiimg-like object
See http://nilearn.github.io/manipulating_images/input_output.html Region definitions, as one image of labels.
- labelslist of str, optional
Full labels corresponding to the labels image. This is used to improve reporting quality if provided. Warning: The labels must be consistent with the label values provided through labels_img.
- background_labelnumber, optional
Label used in labels_img to represent background. Warning: This value must be consistent with label values and image provided. Default=0.
- mask_imgNiimg-like object, optional
See http://nilearn.github.io/manipulating_images/input_output.html Mask to apply to regions before extracting signals.
- smoothing_fwhm
float
, optional. If
smoothing_fwhm
is notNone
, it gives the full-width at half maximum in millimeters of the spatial smoothing to apply to the signal.- standardize{False, True, ‘zscore’, ‘psc’}, optional
Strategy to standardize the signal. ‘zscore’: the signal is z-scored. Timeseries are shifted to zero mean and scaled to unit variance. ‘psc’: Timeseries are shifted to zero mean value and scaled to percent signal change (as compared to original mean signal). True : the signal is z-scored. Timeseries are shifted to zero mean and scaled to unit variance. False : Do not standardize the data. Default=False.
- standardize_confoundsboolean, optional
If standardize_confounds is True, the confounds are z-scored: their mean is put to 0 and their variance to 1 in the time dimension. Default=True.
- high_variance_confoundsboolean, optional
If True, high variance confounds are computed on provided image with
nilearn.image.high_variance_confounds
and default parameters and regressed out. Default=False.- detrendboolean, optional
This parameter is passed to signal.clean. Please see the related documentation for details. Default=False.
- low_passNone or float, optional
This parameter is passed to signal.clean. Please see the related documentation for details
- high_passNone or float, optional
This parameter is passed to signal.clean. Please see the related documentation for details
- t_rfloat, optional
This parameter is passed to signal.clean. Please see the related documentation for details
- dtype{dtype, “auto”}, optional
Data type toward which the data should be converted. If “auto”, the data will be converted to int32 if dtype is discrete and float32 if it is continuous.
- resampling_target{“data”, “labels”, None}, optional
Gives which image gives the final shape/size. For example, if resampling_target is “data”, the atlas is resampled to the shape of the data if needed. If it is “labels” then mask_img and images provided to fit() are resampled to the shape and affine of maps_img. “None” means no resampling: if shapes and affines do not match, a ValueError is raised. Default=”data”.
- memoryjoblib.Memory or str, optional
Used to cache the region extraction process. By default, no caching is done. If a string is given, it is the path to the caching directory.
- memory_levelint, optional
Aggressiveness of memory caching. The higher the number, the higher the number of functions that will be cached. Zero means no caching. Default=1.
- verboseinteger, optional
Indicate the level of verbosity. By default, nothing is printed Default=0.
- strategystr, optional
The name of a valid function to reduce the region with. Must be one of: sum, mean, median, minimum, maximum, variance, standard_deviation. Default=’mean’.
- reportsboolean, optional
If set to True, data is saved in order to produce a report. Default=True.
See also
- __init__(labels_img, labels=None, background_label=0, mask_img=None, smoothing_fwhm=None, standardize=False, standardize_confounds=True, high_variance_confounds=False, detrend=False, low_pass=None, high_pass=None, t_r=None, dtype=None, resampling_target='data', memory=Memory(location=None), memory_level=1, verbose=0, strategy='mean', reports=True)[source]#
- fit(imgs=None, y=None)[source]#
Prepare signal extraction from regions.
All parameters are unused, they are for scikit-learn compatibility.
- fit_transform(imgs, confounds=None, sample_mask=None)[source]#
Prepare and perform signal extraction from regions.
- transform_single_imgs(imgs, confounds=None, sample_mask=None)[source]#
Extract signals from a single 4D niimg.
- Parameters
- imgs3D/4D Niimg-like object
See http://nilearn.github.io/manipulating_images/input_output.html Images to process. It must boil down to a 4D image with scans number as last dimension.
- confoundsCSV file or array-like or pandas DataFrame, optional
This parameter is passed to signal.clean. Please see the related documentation for details. shape: (number of scans, number of confounds)
- sample_maskAny type compatible with numpy-array indexing, optional
shape: (number of scans - number of volumes removed, ) Masks the niimgs along time/fourth dimension to perform scrubbing (remove volumes with high motion) and/or non-steady-state volumes. This parameter is passed to signal.clean.
New in version 0.8.0.
- Returns
- region_signals2D numpy.ndarray
Signal for each label. shape: (number of scans, number of labels)
- inverse_transform(signals)[source]#
Compute voxel signals from region signals
Any mask given at initialization is taken into account.
- Parameters
- signals(2D numpy.ndarray)
Signal for each region. shape: (number of scans, number of regions)
- Returns
- voxel_signals(Nifti1Image)
Signal for each voxel shape: (number of scans, number of voxels)
- get_params(deep=True)#
Get parameters for this estimator.
- Parameters
- deepbool, default=True
If True, will return the parameters for this estimator and contained subobjects that are estimators.
- Returns
- paramsdict
Parameter names mapped to their values.
- set_params(**params)#
Set the parameters of this estimator.
The method works on simple estimators as well as on nested objects (such as
Pipeline
). The latter have parameters of the form<component>__<parameter>
so that it’s possible to update each component of a nested object.- Parameters
- **paramsdict
Estimator parameters.
- Returns
- selfestimator instance
Estimator instance.
- transform(imgs, confounds=None, sample_mask=None)[source]#
Apply mask, spatial and temporal preprocessing
- Parameters
- imgs3D/4D Niimg-like object
See http://nilearn.github.io/manipulating_images/input_output.html Images to process. It must boil down to a 4D image with scans number as last dimension.
- confoundsCSV file or array-like, optional
This parameter is passed to signal.clean. Please see the related documentation for details. shape: (number of scans, number of confounds)
- sample_maskAny type compatible with numpy-array indexing, optional
shape: (number of scans - number of volumes removed, ) Masks the niimgs along time/fourth dimension to perform scrubbing (remove volumes with high motion) and/or non-steady-state volumes. This parameter is passed to signal.clean.
New in version 0.8.0.
- Returns
- region_signals2D numpy.ndarray
Signal for each element. shape: (number of scans, number of elements)
Examples using nilearn.maskers.NiftiLabelsMasker
#
Extracting signals from brain regions using the NiftiLabelsMasker