Relate Fields
Fit a functional relationship between two data fields: b = f(a). Outputs the predicted field_b from the fit and a table of fitted parameters with R-squared goodness-of-fit. Equivalent to Gwyddion's relate.c module.
Inputs
| Name |
Type |
Required |
Description |
| field_a |
DATA_FIELD |
Yes |
Independent variable field |
| field_b |
DATA_FIELD |
Yes |
Dependent variable field |
Outputs
| Name |
Type |
Description |
| predicted |
DATA_FIELD |
Predicted field_b values from the fitted function |
| fit_params |
RECORD_TABLE |
Fitted coefficients and R-squared statistic |
Controls
| Name |
Type |
Default |
Description |
| function |
dropdown |
linear |
Functional form to fit: linear, quadratic, cubic, power, or logarithmic |
Notes
- Linear: b = slope * a + intercept. Reports slope and intercept.
- Quadratic: b = a2a^2 + a1a + a0. Reports a2, a1, a0.
- Cubic: b = a3a^3 + a2a^2 + a1*a + a0. Reports a3, a2, a1, a0.
- Power: b = c * a^n (fitted via log-log regression). Reports exponent and coefficient. Requires positive values in both fields.
- Logarithmic: b = log_coeff * log(a) + intercept. Requires positive values in field_a.
- R-squared is always reported as the last row: values near 1.0 indicate a good fit.
- Both fields are flattened and truncated to the shorter length when they differ in total pixel count.
- The predicted output retains field_b's shape and metadata.
