fchebyshev_split

pydl.pydlutils.trace.fchebyshev_split(x, m)

Compute the first m Chebyshev polynomials, but modified to allow a split in the baseline at \(x=0\). The intent is to allow a model fit where a constant term is different for positive and negative x.

Parameters

xarray-like

Compute the Chebyshev polynomials at these abscissa values.

mint

The number of Chebyshev polynomials to compute. For example, if \(m = 3\), \(T_0 (x)\), \(T_1 (x)\) and \(T_2 (x)\) will be computed.

Returns

numpy.ndarray