Estimate orbital expression character count

Estimates the character count of the orbital expression that would be generated for a model, without actually generating it. This is useful during hyperparameter tuning when you want to track SQL size as a metric but don't want to pay the cost of generating the full orbital object for every candidate model.

Usage

estimate_orbital_size(x, ...)

# S3 method for class 'xgb.Booster'
estimate_orbital_size(x, ...)

# S3 method for class 'lgb.Booster'
estimate_orbital_size(x, ...)

# S3 method for class 'ranger'
estimate_orbital_size(x, ...)

# S3 method for class 'randomForest'
estimate_orbital_size(x, ...)

# S3 method for class 'rpart'
estimate_orbital_size(x, ...)

# S3 method for class 'constparty'
estimate_orbital_size(x, ...)

# S3 method for class 'catboost.Model'
estimate_orbital_size(x, ...)

# S3 method for class 'glm'
estimate_orbital_size(x, ...)

# S3 method for class 'lm'
estimate_orbital_size(x, ...)

# S3 method for class 'glmnet'
estimate_orbital_size(x, ..., penalty = NULL)

# S3 method for class 'earth'
estimate_orbital_size(x, ...)

# S3 method for class 'recipe'
estimate_orbital_size(x, ...)

# S3 method for class 'workflow'
estimate_orbital_size(x, ...)

# S3 method for class 'tailor'
estimate_orbital_size(x, ...)

Arguments

x

A fitted model object, workflow, prepped recipe, or fitted tailor.

...

Additional arguments passed to methods.

penalty

For glmnet models, the penalty value (lambda) to use. If the model was fit with a single lambda, this is used by default. Otherwise, you must specify a value.

Value

An integer estimate of the total character count of the orbital expression.

Details

The estimation uses model metadata (tree structure, number of parameters, feature names) to approximate the size of the resulting orbital expression. The estimates are typically within 5-10% of the actual size.

For tree-based models, this function is much faster than generating the full orbital object because it only needs to inspect the tree structure, not convert each tree to an R expression.

This function aims to support all the same models and preprocessing operations as orbital(), but does not yet reach all of them. A model with no estimate is an error rather than a zero, including inside a workflow, since a workflow's model is usually the bulk of the expression and counting it as free would report the recipe's size as the whole. If you find a case where orbital() works but estimate_orbital_size() does not, please file an issue.

See also

orbital() for generating orbital objects.

Examples

library(xgboost)

# Estimate size for an xgboost model
x <- as.matrix(mtcars[, -1])
y <- mtcars[, 1]
model <- xgboost(
  x = x,
  y = y,
  nrounds = 50,
  max_depth = 4,
  verbosity = 0,
  nthreads = 1
)

estimate_orbital_size(model)
#> [1] 26404
library(recipes)
library(workflows)
library(parsnip)

# Estimate size for a workflow
rec <- recipe(mpg ~ ., data = mtcars) |>
  step_normalize(all_numeric_predictors())

wf <- workflow() |>
  add_recipe(rec) |>
  add_model(linear_reg()) |>
  fit(mtcars)

estimate_orbital_size(wf)
#> [1] 872