bin_index

std.stats.bin_index · Level L4

The bin each value falls into, for bins of equal width starting at lo: ⌊(x − lo)/width⌋, as an integer index. Values below lo get negative bins; nothing is clipped.

⌊(x − lo)/w⌋

Signature

bin_index(x: f64[n], lo: f64[], width: f64[]) → i64[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]lof64[]widthf64[]SubtractshiftedFloorDivqCastbinbini64[n]
  • input
  • operation
  • constant
  • call
  • output

Verification

  • Signature proven by NOVA’s shape solver, for every size.
  • Equal to the reference np.floor_divide(x - lo, width) in exact rational arithmetic, on all 40 test cases.
  • All 164 int64 results are exact: the error is zero.
  • Interpreter and NumPy backend return bit-identical results.
Accuracy in detail
correctly rounded (the int64 nearest the exact value)
100%
bit-equal to the NumPy formula in int64
99%
largest error, in units in the last place
0

Identity

Calls
—
Called by
—
sha256:be5e35e23b1bb1617a0b7131127c40e7dccc21ea715e326937c920ae594c9a1f

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

Control handle

Symbol
Ω:std.stats.bin_index · Ω:bin_index
Pins
sha256:83d626c7ab9b57788cf87f08e8560cfd749def23a65b383b7e14816a413e9db2this graph alone
Evidence
sha256:b2b42b5dd86e306c5be14313cc6a254ca2467e2ce5e43ff7f93cf0956c1bc1a1the 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.