sign

std.elementwise.sign · Level L1

Sign of each element (−1, 0 or 1), from two comparison masks. Exact.

[x > 0] − [x < 0]

Signature

sign(x: f64[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 a call to another library function; select it to open that function.

xf64[n]0.0GreaterposLessnegSubtractyyf64[n]
  • input
  • operation
  • constant
  • call
  • output

Verification

  • Signature proven by NOVA’s shape solver, for every size.
  • Equal to the reference np.sign(x) in exact rational arithmetic, on all 40 test cases.
  • All 131 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
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Called by
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sha256:c98eb1dd9defda71f2f5b2258d7d99d624cb49b94ec814d7177e7911ab2ba99e

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