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datasets.miscfx_sp

Module: datasets.miscfx_sp

Misc function performing operations on datasets which are based on scipy

mvpa.datasets.miscfx_sp.detrend(dataset, perchunk=False, model='linear', polyord=None, opt_reg=None)

Given a dataset, detrend the data inplace either entirely or per each chunk

Parameters:

• dataset (Dataset) – dataset to operate on
• perchunk (bool) – either to operate on whole dataset at once or on each chunk separately
• model – Type of detrending model to run. If ‘linear’ or ‘constant’, scipy.signal.detrend is used to perform a linear or demeaning detrend. Polynomial detrending is activated when ‘regress’ is used or when polyord or opt_reg are specified.
• polyord (int or list) – Order of the Legendre polynomial to remove from the data. This will remove every polynomial up to and including the provided value. For example, 3 will remove 0th, 1st, 2nd, and 3rd order polynomials from the data. N.B.: The 0th polynomial is the baseline shift, the 1st is the linear trend. If you specify a single int and perchunk is True, then this value is used for each chunk. You can also specify a different polyord value for each chunk by providing a list or ndarray of polyord values the length of the number of chunks.
• opt_reg (ndarray) – Optional ndarray of additional information to regress out from the dataset. One example would be to regress out motion parameters. As with the data, time is on the first axis.