softsign

std.elementwise.softsign · Level L0

Softsign: a smooth, bounded alternative to tanh. Calls abs.

x / (1 + |x|)

Signature

softsign(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]1.0absaxAdddenDivideyyf64[n]
  • input
  • operation
  • constant
  • call
  • output

Verification

  • Signature proven by NOVA’s shape solver, for every size.
  • Equal to the reference x / (1 + np.abs(x)) in exact rational arithmetic, on all 40 test cases.
  • All 154 float64 results inside the running error bound; the closest uses 63% of it.
  • Interpreter and NumPy backend return bit-identical results.
Accuracy in detail
correctly rounded (the float64 nearest the exact value)
94%
bit-equal to the NumPy formula in float64
100%
largest error, in units in the last place
0.92

Identity

Calls
abs
Called by
—
sha256:dc77da571580ff51828de0ee57eebdc482b7651967852af989afa23b677c4e81

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