Allows AST masking to be switched off after a given number of iterations
"
mask on all iterations"
. However, if parameter
"
ast.zero_notlast"
is set, the mask will will not be applied on the last iteration, even if ast.zero_niter is zero.
This feature will probably be useful for deep point-source observations for which the large-scale
noise is not as important, but keeping as much data around the edges of the map is. Note, any
initial iterations specified by parameter "
ast.skip"
are not included in the count of iterations. If
ast.zero_niter is greater than zero but less than 1.0, the AST mask will be used until the normalized
change in the map between iterations drops below the ast.zero_freeze value. A negative value for
ast.zero_niter will disable all masking of the AST model. If a value is set for "
ast.zero_niter"
, the
iterative map-making process will not terminate until the number of iterations required by the
supplied "
ast.zero_niter"
value have occurred, regardless of whether the condition specified by
parameter "
maptol"
is achieved earlier. [0.0]