sicmutils.util.aggregate — sicmutils 0.18.0

Utilities for aggregating sequences.

generic-sum clj/s

(generic-sum xs)

(generic-sum f low high)

Sums either:

• a series xs of numbers, or
• the result of mapping function f to (range low high)

Using the generic sicmutils.generic/+ function.

halt-at clj/s

(halt-at pred)

Returns a transducer that ends transduction when pred (applied to the aggregation in progress) returns true for an aggregation step.

NOTE: This transducer should come first in a chain of transducers; it only inspects the aggregate, never the value, so putting it first will prevent unnecessary transformations of values if the aggregate signals completion.

kahan-sum clj/s

(kahan-sum)

(kahan-sum [sum c] x)

Implements a fold that tracks the summation of a sequence of floating point numbers, using Kahan's trick for maintaining stability in the face of accumulating floating point errors.

scanning-sum clj/s

(scanning-sum xs)

(scanning-sum f low high)

Returns every intermediate summation from summing either:

• a series xs of numbers, or
• the result of mapping function f to (range low high)

Using Kahan's summation trick behind the scenes to keep floating point errors under control.

sum clj/s

(sum xs)

(sum f low high)

Sums either:

• a series xs of numbers, or
• the result of mapping function f to (range low high)

Using Kahan's summation trick behind the scenes to keep floating point errors under control.