BSpline interpolation and approximation boundary conditions

[taoari]

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For BSpline interpolation, there are four pretty standard boundary conditions: clamped, natural, not-a-knot, periodic (https://docs.scipy.org/doc/scipy/reference/generated/scipy.interpolate.make_interp_spline.html).

For curve2d, I see clamped, unclamped, and periodic examples. However, for curve fitting (interpolation and approximation), I see no such examples. Is it possible to achieve interpolation and approximation with different boundary conditions? I am mainly interested in the periodic case, but it is best if there will also be natural and not-a-knot boundary conditions.

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Configuration:

• OS: [e.g. Windows 10, Ubuntu 18.10]
• Python distribution: [e.g. OS default, python.org, Anaconda]
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• geomdl install source: GitHub / PyPI / Anaconda
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