curve: explicitly name override arguments so n is not confused with name
curve: explicitly name override arguments so n is not confused with name

jread-usgs/gsplot,jiwalker-usgs/gsplot,dpattermann-usgs/gsplot,aappling-usgs/gsplot,aappling-usgs/gsplot,USGS-R/gsplot,jiwalker-usgs/gsplot,lindsaycarr/gsplot,dpattermann-usgs/gsplot,jread-usgs/gsplot,ldecicco-USGS/gsplot,lindsaycarr/gsplot,ldecicco-USGS/gsplot