Function opendp::transformations::make_consistent_b_ary_tree

pub fn make_consistent_b_ary_tree<TIA, TOA>(
    branching_factor: usize
) -> Fallible<Function<Vec<TIA>, Vec<TOA>>>where
    TIA: CheckAtom + Clone,
    TOA: Float + RoundCast<TIA>,

Postprocessor that makes a noisy b-ary tree internally consistent, and returns the leaf layer.

The input argument of the function is a balanced b-ary tree implicitly stored in breadth-first order Tree is assumed to be complete, as in, all leaves on the last layer are on the left. Non-existent leaves are assumed to be zero.

The output remains consistent even when leaf nodes are missing. This is due to an adjustment to the original algorithm to apportion corrections to children relative to their variance.

Citations

• HRMS09 Boosting the Accuracy of Differentially Private Histograms Through Consistency, section 4.1

Arguments

• branching_factor - the maximum number of children

Generics

• TIA - Atomic type of the input data. Should be an integer type.
• TOA - Atomic type of the output data. Should be a float type.