Randomization statistics utilities (spynal.randstats.utils)¶
Utility functions for randomization statistics
Function list¶
resamples_to_pvalue : Compute p value from observed and resampled statistic values
confint_to_indexes : Returns indexes into resampled stats corresponding to given confints
jackknife_to_pseudoval : Compute single-trial pseudovalues from leave-one-out jackknife estimates
Function reference¶
- resamples_to_pvalue(stat_obs, stat_resmp, axis=0, tail='both')¶
Compute p value with given tail from observed and resampled values of a statistic
- Parameters:
stat_obs (ndarray, shape=(...,1,...)) – Statistic values for actual observed data
stat_resmp (ndarray, shape=(...,n_resamples,...)) – Statistic values for randomly resampled data
axis (int, default: 0) – Axis in stat_resmp corresponding to distinct resamples (should correspond to a length=1 axis in stat_obs)
tail ({'both','right','left'}, default: 'both' (2-tailed test)) –
Specifies tail of test to perform:
’both’ : 2-tail test – test for abs(stat_obs) > abs(stat_resmp)
’right’ : right-sided 1-tail test – tests for stat_obs > stat_resmp
’left’ : left-sided 1-tail test – tests for stat_obs < stat_resmp
- Returns:
p – p values from resampling test. Same size as stat_obs.
- Return type:
ndarray, shape=(…,1,…)
- confint_to_indexes(confint, n_resamples)¶
Return indexes into set of resamples corresponding to given confidence interval
Typically used for bootstrap resampled confidence intervals. Could be used for jackknifes.
- Parameters:
confint (float) – Desired confidence interval, in range 0-1. eg, for 99% confidence interval, input 0.99
n_resamples (int) – Number of resamples (eg bootstraps)
- Returns:
conf_indexes – Indexes into sorted resamples corresponding to [lower,upper] confidence interval
- Return type:
list[int], shape=(2,)
- jackknife_to_pseudoval(x, xjack, n)¶
Compute single-trial pseudovalues from leave-one-out jackknife estimates
- Parameters:
x (ndarray, shape=Any) – Statistic computed on full observed data. Any arbitrary shape.
xjack (ndarray, shape=Any) – Statistic computed on jackknife resampled data
n (int) – Number of observations (trials) used to compute x
- Returns:
pseudo – Single-trial jackknifed pseudovalues. Same shape as xjack.
- Return type:
ndarray, shape=Any