parameter-rules
At its defaults it draws the l-curve, and where four rules put λ. The norm of the solution against the norm of its residual, on logarithmic axes, as λ sweeps eight decades. The curve has a corner: to the left of it the noise is being amplified and to the right the signal is being thrown away. Four points are marked — the three rules that use only the data, and the oracle, which requires the exact answer and is not a method.
parameter-rules is one function in lib/figures/regular.js —
regularisation — the filter, the corner, and the answer that is a choice. Everything below came out of it during this build, at
arguments taken from the essays rather than invented for this page. A figure here is the
figure a reader meets in an essay, and if the generator changes, this page changes with it.
At its defaults
Drawn even though every essay passes arguments — which on this site is every essay, at 100% of placements since the standard pass. A default nothing exercises is a trap for the next essay to call this with none, and this is the page where a default that has drifted from the figures around it becomes visible.
The norm of the solution against the norm of its residual, on logarithmic axes, as λ sweeps eight decades. The curve has a corner: to the left of it the noise is being amplified and to the right the signal is being thrown away. Four points are marked — the three rules that use only the data, and the oracle, which requires the exact answer and is not a method.
noise: 0.001
The arguments are the ones Choosing without knowing passes. A value drawn at the generator's defaults instead would be a picture no essay asked for and no assertion has been run against.
The norm of the solution against the norm of its residual, on logarithmic axes, as λ sweeps eight decades. The curve has a corner: to the left of it the noise is being amplified and to the right the signal is being thrown away. Four points are marked — the three rules that use only the data, and the oracle, which requires the exact answer and is not a method.
noise: 0.01
The arguments are the ones Choosing without knowing passes. A value drawn at the generator's defaults instead would be a picture no essay asked for and no assertion has been run against.
The norm of the solution against the norm of its residual, on logarithmic axes, as λ sweeps eight decades. The curve has a corner: to the left of it the noise is being amplified and to the right the signal is being thrown away. Four points are marked — the three rules that use only the data, and the oracle, which requires the exact answer and is not a method.
What it checked while drawing
Every figure above asserted its own claims on the way to being drawn, and a claim that failed
would have failed the build rather than drawn a wrong picture. Those assertions used to leave
no trace at all: a passing one returned true and the only evidence the figure had
checked anything was that nothing crashed. The list below is what they actually said, collected
by running this generator with an observer installed — not a description of
what it is believed to check.
5 distinct claims across 3 sets of arguments, grouped below by shape — because most of them are one sentence with a different number in it, and how many separate times that sentence was put to the test is the informative part.
a noise level small enough to be noise
and at least one pays a real price for not knowing the answer
discrepancy principle does not beat the oracle
generalised cross-validation does not beat the oracle
L-curve corner does not beat the oracle
Against the rule
The rule does not apply to it. It factorises nothing, so there is no residual it could be withholding. That is worth stating rather than leaving blank: a site that reported the rule as satisfied by every generator would be counting mostly generators the rule never reached.
Across the library: the rule bites on 52
of 99 generators —
37 print a residual and
15 are exempt with a published reason;
47 factorise nothing.
Read from lib/residual-rule.js, which is the same body the gate enforces from,
and the gate's last check fails the build if this page and it disagree about any generator.
Where it is called
Changing this generator changes every figure on this list. That is what makes the list worth publishing rather than keeping in a check script.