shuffle

std.seq.shuffle · Level L4

A reproducible random permutation of x: draw one uniform number per element, then sort the elements by their numbers.

x[argsort(uniform_draws(state, x))]

Signature

shuffle(x: f64[n], state: i64[3]) → f64[n]

Structure

The function as NOVA stores it: one box per input, operation and output, and arrows that carry values. A double border marks another library function this one runs — called once, or by Scan once per element; select it to open that function.

xf64[n]statei64[3]uniform_drawsuArgSortorderCastidxGathershuffledshuffledf64[n]
  • input
  • operation
  • constant
  • call
  • output

Verification

  • Signature proven by NOVA’s shape solver, for every size.
  • Equal to the reference x sorted by its Wichmann–Hill draws in exact rational arithmetic, on all 40 test cases.
  • All 162 float64 results are exact: the error is zero.
  • Interpreter and NumPy backend return bit-identical results.
Accuracy in detail
correctly rounded (the float64 nearest the exact value)
100%
bit-equal to the NumPy formula in float64
100%
largest error, in units in the last place
0

Identity

Calls
uniform_draws
Called by
—
sha256:fe5eaffa52ae0d01001d581acfc9889212f1a44a8c2554d2b8a714d966304f10

The semantic hash of the graph. It changes when the program changes, and never when only its documentation does.

Control handle

Symbol
Ω:std.seq.shuffle · Ω:shuffle
Pins
sha256:a3ac7a87a0972fe99a1330c581cba422847c31f07bba5939f0c644b04728b3e2this graph and the 2 it reaches through calls
Evidence
sha256:5bc7b26938b65a75ec1f984dad3130581a02b120fa31a5d9bbf4f09317b129fathe hash of its verification record
Needs
no capability: a pure function

Through NOVA’s control layer, the symbol launches this function only while the program still matches what it pins: a change to this graph, or to any graph it reaches, needs a migration first.