commensura.math — com.github.crinklywrappr/commensura 1.0.39

Math functions over quantities and intervals — the ones that carry dimensions.

(require '[commensura.math :as m]) (m/sqrt (c/pow (u/meter 1) 2)) ;=> 1 meter (exact when a perfect root) (m/abs (u/meter -5)) ;=> 5 meter (m/min (u/foot 1) (u/inch 6)) ;=> 6 inch (physical order, keeps the unit) (m/mod (u/hour 25) (u/hour 24));=> 1 hour

Only functions that touch dimensions live here — preserving them (abs/mod/min/max/ floor/ceil/round), scaling them (sqrt/root), or crossing the boundary (sign: dimensioned → dimensionless). Raising to a power is a core verb (commensura.core/pow), which sqrt/root are built on. Transcendentals (exp/ln/sin/…) are intentionally absent: they only ever map dimensionless → dimensionless, so they belong to plain numeric code.

Over intervals, the monotone functions lift by mapping the endpoints — sign/floor/ceil/round directly, abs with a special case when the interval spans zero — and sqrt/root scale through. mod/rem are the exception: scalar-only, and they reject an interval argument, because modular reduction is discontinuous and cannot be soundly lifted ([23,25] mod 24 is {23} ∪ [0,1], not a single interval). Names shadow clojure.core, so use this namespace qualified (m/abs), never :refer. Comparisons come from commensura.core.

abs clj

(abs x)

Absolute value; dimension-preserving. Over a zero-spanning interval the lower bound is 0; on an Uncertain, |value| carries the spread unchanged.

ceil clj

(ceil x)

Smallest integer ≥ x, in x's unit. On an Uncertain, rounds the central value and keeps the spread.

floor clj

(floor x)

Largest integer ≤ x, in x's unit. On an Uncertain, rounds the central value and keeps the spread.

max clj

(max x)

(max x y)

(max x y & more)

The physically larger value (variadic); keeps the winner's unit (and, for an Uncertain, its σ). Conforming.

min clj

(min x)

(min x y)

(min x y & more)

The physically smaller value (variadic); keeps the winner's unit (and, for an Uncertain, its σ). Conforming.

mod clj

(mod x y)

x modulo y — conforming, dimension-preserving (keeps x's unit). Scalar-only: an interval or uncertain argument is rejected (modular reduction is discontinuous, so it cannot be soundly lifted).

rem clj

(rem x y)

Remainder of x by y — conforming, dimension-preserving. Scalar-only: an interval or uncertain argument is rejected (see mod).

root clj

(root x q)

The q-th root.

round clj

(round x)

Nearest integer (half → +∞), in x's unit. On an Uncertain, rounds the central value, keeping σ.

sign clj

(sign x)

Sign of a value: a plain -1, 0, or 1, for a value of any dimension. On an Uncertain, the sign of the central value (the spread does not carry — this is a classification, not a measurement).

sqrt clj

(sqrt x)

Square root.