Exponential response
y = 2.5 exp(0.8 x)
- x chart
- identity
- y chart
- log
- slope
- 0.800
- RMSE
- 9.21e-16
The output log chart turns exponential growth into a line with slope 0.8.
This page reframes the demos around a testable claim: choose the coordinate chart that makes a model simple, then use GlobalMOO-style Pareto search inside maps that preserve the model's constraints. The singularity language is corrected below: the bounded object is the transformed diagnostic, not necessarily the original field.
Synthetic exponential, power-law, and logistic generators recover their expected charts.
The raw SINDy library needs two terms; the logit coordinate needs one constant term.
exp, sigmoid, and softmax maps keep every candidate inside its physical domain.
Mass-action products become additive in log coordinates to numerical precision.
Each case ranks candidate charts by linear residual and interpretability. The winner is a coordinate system, not a new physical law.
y = 2.5 exp(0.8 x)
The output log chart turns exponential growth into a line with slope 0.8.
y = 3 x^1.7
The log-log chart recovers the scaling exponent as the fitted slope.
y = 1 / (1 + exp(-(1.4 x - 0.3)))
The logit output chart reveals the latent linear generator.
A SINDy-style library sees the logistic equation as a two-term polynomial in raw coordinates. The logit coordinate exposes the one-term latent generator.
x' = 0.9 x - 0.18 x^2z' = 0.9, where z = log(x / (5 - x))The nonlinear logistic ODE becomes a constant-velocity model after the logit coordinate is used.
For positive concentrations, log coordinates turn multiplicative mass-action structure into an additive linear model without breaking positivity.
The optimizer should search an unconstrained latent vector, while the model receives values already mapped into the physical domain.
x = exp(z)Rates, densities, scales, and stiffness parameters never cross zero.
p = sigmoid(z)Probabilities and gates stay in (0, 1) without repair penalties.
w = softmax(z)Mixture weights remain nonnegative and sum to one at every evaluation.
| search mode | evaluations | valid | best score | interpretation |
|---|---|---|---|---|
| raw candidate values | 144 | 13.9% | 0.861 | Many evaluations are invalid before scoring. |
| mapped latent values | 144 | 100.0% | 0.983 | Every candidate is meaningful to the simulator. |
L_BG[r^n] = n and D_BG[r^n] = exp(n) for r > 0 and positive fields.
L_BG[1/r] = -1, while D_BG[1/r] = exp(-1), not -1.
The transformed diagnostic is bounded; the original field can still diverge.
These external sources anchor the corrected demo framing and the paper expansion.
Brunton, Proctor, and Kutz
Sparse governing-equation discovery baseline.
Williams, Kevrekidis, and Rowley
Lifted-coordinate dynamics and dictionary selection context.
Box and Cox
Classical precedent for transform selection as statistical modeling.
Deb, Pratap, Agarwal, and Meyarivan
Canonical Pareto search reference for multiobjective optimization.
GlobalMOO
API framing for ask-tell style constrained model search.