sqrtfilter is a numeric filter whose value is the integer square root of its argument:
sqrt 4 ≡ 2 sqrt 26 ≡ 5If the argument to the
sqrtfilter does not match the currentposition, neither does the
sqrtfilter. If the argument to
sqrtis negative, the
sqrtfilter does not match the position.
sqrt filter is mainly used in computing the Euclidean distance between two squares s and t, but the distance
has to be scaled because CQL only has integers. See the cql file averagedistance.cql for an example of this usage.