Parameters for mask

• ahfinder::ahf_mask (steerable)
  The mask is 0 inside the horizon and 1 outside, and is used in black-hole excision techniques. By default the mask is off. It can be enabled by setting ahf_mask = "strong", which sets the mask only if the finder is sure that a horizon was found, or by setting ahf_mask = "weak", which makes the finder set the mask also if a horizon is probably there but either the resolution or lmax are to low to really resolve it.
• ahfinder::ahf_masktype (steerable)
  The mask can be of two types. Either ahf_masktype = "simple", which masks a cube contained inside the horizons, or ahf_masktype = "lego", which masks a lego-sphere.
• ahfinder::ahf_maskshrink (steerable)
  Sets a buffer zone between the region inside the horizon and the region where the mask is 0, by limiting the mask to a region smaller than ahf_maskshrink times the horizon radius. The default value is 0.8.
• ahfinder::ahf_maskbuffer (steerable)
  Sets a buffer zone between the region inside the horizon and the region where the mask is 0 with a width of at least ahf_maskbuffer grid points. The default value is 5.