max_drawdown

std.stats.max_drawdown · Level L2

Maximum drawdown: the largest fall from a running peak to a later value, as used for price series.

maxₜ (maxⱼ≤ₜ xⱼ − xₜ)

Signature

max_drawdown(x: f64[n]) → f64[]

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]CumMaxpeakSubtractdropReduceMaxworstworstf64[]
  • input
  • operation
  • constant
  • call
  • output

Verification

  • Signature proven by NOVA’s shape solver, for every size.
  • Equal to the reference max over t of (max(x[:t+1]) - x[t]) in exact rational arithmetic, on all 40 test cases.
  • All 40 float64 results inside the running error bound; the closest uses 75% of it.
  • 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
0.50

Identity

Calls
—
Called by
—
sha256:4c484eb5e19e57da736b7c2072a276195fe5b5499b2c626ce98d8e5734fdc7ff

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.max_drawdown · Ω:max_drawdown
Pins
sha256:15a5c357ab189b344b783ad2b2082d0ee2d05c48e77eba70f643b7412dd1dcbfthis graph alone
Evidence
sha256:e8b394ffd653e49bbfd490579c06743123619a91a7f6d085cb449110ebfd9891the 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.