permute

std.seq.permute · Level L3

Reorder a vector by a permutation: element i of the result is x[perm[i]]. A Gather.

yᵢ = x[permᵢ]

Signature

permute(x: f64[n], perm: i64[n]) → 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]permi64[n]Gatheryyf64[n]
  • input
  • operation
  • constant
  • call
  • output

Verification

  • Signature proven by NOVA’s shape solver, for every size.
  • Equal to the reference x[perm] in exact rational arithmetic, on all 40 test cases.
  • All 159 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
—
Called by
—
sha256:8133da545432af31c41632dc5845ff28d52c8c300c6398d9ba8be8658257a018

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.permute · Ω:permute
Pins
sha256:58d64b3ea9f5a6416e565f37abf46172a6e88f38c4b952baddedd72a45c3f5b9this graph alone
Evidence
sha256:88c3e77ef1c1cdf6301b299af6bda267d1296509c77ebeee42386f6511fde472the 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.