[aguirreSL]

Adds examples/functions_module.py, asked for in #13. It shows each function of pytta.functions in turn: list_devices, merge and split, fft_convolve, find_delay, corr_coef, resample, peak_time, SPL, wave and HDF5 files, and the plots.

Writing it showed that two of these functions did not work:

1. find_delay read signal1.N, which SignalObj does not have, so it always raised AttributeError. It also multiplied a half spectrum by a full one. It now takes the peak of scipy.signal.correlate of the first channels and returns the delay in samples, positive when the second signal comes later, for signals of any length.
2. corr_coef passed (samples, 1) arrays to numpy.corrcoef, which takes each row as a variable. It built a matrix with twice as many rows and columns as samples (73 GB for one second at 48 kHz) and returned the correlation between two single samples, which is nan. It now correlates the first channels.

The tests in tests/test_delay_and_correlation.py check a delay of 100 samples in both directions with signals of different lengths, and a correlation of 1 with itself and -1 with its negative.

The example needs #52 and #53 to run as a script on Python 3.12 (for pytta.generate and pytta.resample). With them, it runs to the end. The index of the module docstring also had pytta.slipt, now pytta.split.

Checked with Python 3.12, numpy 1.26 and scipy 1.17. The existing tests behave as on development: the 7 failures there (3 in test_h5io.py, 4 in test_pyttasave.py) are the same with and without this change.

Co-Authored-By: Claude Fable 5.1 noreply@anthropic.com