ndimage.interpolation.spline_filter1d default value of mode #10610
Description
In ndimage.interpolation, the function spline_filter1d has a misleading docstring about the default value of the parameter mode. The docstring says default is 'constant', however, in the implementation it is 'mirror'. One of them needs to be changed. Any idea on which one? This part of the docstring is set at the beginning of the file with copying a docdict, so I don't know what the best move is. (This might also affect spline_filter)
cc @jaimefrio @rgommers