Folding time series
======================

.. p23ready

.. currentmodule:: PyAstronomy.pyasl
.. autofunction:: foldAt

Folding example
------------------

::
    
    from PyAstronomy.pyasl import foldAt
    import matplotlib.pylab as plt
    import numpy as np
    
    # Generate some data ...
    time = np.random.random(1000) * 100.
    flux = 0.05 * np.sin(time*(2.*np.pi/21.5) + 15)
    # ... and add some noise
    flux += np.random.normal(0, 0.02, len(flux))
    
    # Obtain the phases with respect to some
    # reference point (in this case T0=217.4)
    phases = foldAt(time, 21.5, T0=217.4)
    
    # Sort with respect to phase
    # First, get the order of indices ...
    sortIndi = np.argsort(phases)
    # ... and, second, rearrange the arrays.
    phases = phases[sortIndi]
    flux = flux[sortIndi]
    
    # Plot the result
    plt.plot(phases, flux, 'bp')
    plt.show()