eelbrain.testnd.ttest_1samp

class eelbrain.testnd.ttest_1samp(y: Union[eelbrain._data_obj.NDVar, str], popmean: float = 0, match: Union[eelbrain._data_obj.Factor, eelbrain._data_obj.Interaction, eelbrain._data_obj.NestedEffect, str] = None, sub: Union[eelbrain._data_obj.Var, numpy.ndarray, str] = None, ds: eelbrain._data_obj.Dataset = None, tail: int = 0, samples: int = 10000, pmin: float = None, tmin: float = None, tfce: Union[float, bool] = False, tstart: float = None, tstop: float = None, parc: str = None, force_permutation: bool = False, **criteria)

Mass-univariate one sample t-test

Parameters:
y : NDVar

Dependent variable.

popmean : scalar

Value to compare y against (default is 0).

match : None | categorial

Combine data for these categories before testing.

sub : index

Perform test with a subset of the data.

ds : None | Dataset

If a Dataset is specified, all data-objects can be specified as names of Dataset variables

tail : 0 | 1 | -1

Which tail of the t-distribution to consider: 0: both (two-tailed); 1: upper tail (one-tailed); -1: lower tail (one-tailed).

samples : int

Number of samples for permutation test (default 10,000).

pmin : None | scalar (0 < pmin < 1)

Threshold for forming clusters: use a t-value equivalent to an uncorrected p-value.

tmin : scalar

Threshold for forming clusters as t-value.

tfce : bool | scalar

Use threshold-free cluster enhancement. Use a scalar to specify the step of TFCE levels (for tfce is True, 0.1 is used).

tstart : scalar

Start of the time window for the permutation test (default is the beginning of y).

tstop : scalar

Stop of the time window for the permutation test (default is the end of y).

parc : str

Collect permutation statistics for all regions of the parcellation of this dimension. For threshold-based test, the regions are disconnected.

force_permutation: bool

Conduct permutations regardless of whether there are any clusters.

mintime : scalar

Minimum duration for clusters (in seconds).

minsource : int

Minimum number of sources per cluster.

Notes

Data points with zero variance are set to t=0.

Attributes:
clusters : None | Dataset

For cluster-based tests, a table of all clusters. Otherwise a table of all significant regions (or None if permutations were omitted). See also the find_clusters() method.

difference : NDVar

The difference value entering the test (y if popmean is 0).

n : int

Number of cases.

p : NDVar | None

Map of p-values corrected for multiple comparison (or None if no correction was performed).

p_uncorrected : NDVar

Map of p-values uncorrected for multiple comparison.

t : NDVar

Map of t-values.

tfce_map : NDVar | None

Map of the test statistic processed with the threshold-free cluster enhancement algorithm (or None if no TFCE was performed).

Methods

cluster(self, cluster_id) Retrieve a specific cluster as NDVar
compute_probability_map(self, **sub) Compute a probability map
find_clusters(self[, pmin, maps]) Find significant regions or clusters
find_peaks(self) Find peaks in a threshold-free cluster distribution
info_list(self[, computation]) List with information about the test
masked_difference(self[, p, name]) Difference map masked by significance
masked_parameter_map(self[, pmin]) Create a copy of the parameter map masked by significance