This parameter allows an alternative mask to be used on the first iteration. If a value is supplied for " flt.zero_mask0" , it will be used in place of parameter "flt.zero_mask" on the first iteration only. If no value is supplied for " flt.zero_mask0" , the value supplied for " flt.zero_mask" will be used on all iterations including the first. Setting " flt.zero_mask0" to zero will cause no masking to be used on the first iteration. [$<$undef$>$]

MAKEMAP, CALCQU