Version 1.2.1

Guillaume Dumas fixed an error caused by warn not being imported.

Version 1.2

• Implemented solving, i.e., finding times at which the spline assumes a given value.
• Improved input-handling of from_function.

v1.1

• Added simple example to documentation.
• Added plot method.
• Added from_data class method to create a spline from data.
• Added functions to add and join splines.
• Improved get_state to work with multiple time points at once.
• Improved efficiency for splines with many anchors.