Recognised values for 'action': NOP do nothing
SKIP drop line on match, read next line
DROP
KEEP keep line on match, do not test further
SKIP_NOT drop line if not matching
DROP_NOT
SKIP_IF_NOT
DROP_IF_NOT
KEEP_NOT keep line if not matching rule, do not test further
Each action has also a 'disabled' variant, causing it to be ignored.
NOP_DISABLED
SKIP_DISABLED
DROP_DISABLED
KEEP_DISABLED
SKIP_NOT_DISABLED
DROP_NOT_DISABLED
KEEP_NOT_DISABLED
The _NOT / _IF_NOT variants effectively invert the comparison operation.
(A == B) becomes (A != B), (1 <= 1="" a="" <="100)" becomes="" (a="" or=""> 100).=>
Certain VCF read functions support the fast pre-filtering mechanism of WhopGenome.
The pre-filtering mechanism is a list of rules that describe how and what to check in
SNP descriptions and is executed very quickly without using any R code.
Every rule specifies the column of data (e.g. INFO, POS, FILTER), the key in the column (e.g. AF in the INFO column),
the type of comparison , reference values to compare against and whether to keep or drop the line if the rule matches.