Reduces spurious large scale structure in the final map outside a circle of given radius
"
ast.zero_notlast"
). If a value is supplied for this parameter, it can be a
single real value, or a comma-separated list of three real values in parentheses. If one value is supplied, it
should be the radius of the circle in decimal degrees (the centre of the circle defaults to the coordinates at the
tangent point of the map). If three values are supplied they should be the central longitude, latitude and
radius of the circle, in decimal degrees, in the coordinate system of the map (e.g., RA and Dec.).
[<undef>
]