MAINT: Check for non-zero data size in swt_axis and swt as well.
MAINT: Check for non-zero data size in swt_axis and swt as well.

rgommers/pywt,PyWavelets/pywt,grlee77/pywt,PyWavelets/pywt,rgommers/pywt,rgommers/pywt,rgommers/pywt,grlee77/pywt