from marvin.tools.maps import Maps
maps = Maps('1-22301')
nii = maps['emline_gflux_nii_6585']
ha = maps['emline_gflux_ha_6564']
masks = maps.get_bpt(show_plot=False, return_figure=False)
sf = masks['sf']['global']
mask_non_sf = ~sf * ha.pixmask.labels_to_value('DONOTUSE')
mask = ha.mask | mask_non_sf
nii_ha = nii / ha
nii_ha.plot(mask=mask, cblabel='[NII]6585 / Halpha flux ratio')