Package 'tidypredict'

Title: Run Predictions Inside the Database
Description: It parses a fitted 'R' model object, and returns a formula in 'Tidy Eval' code that calculates the predictions. It works with several databases back-ends because it leverages 'dplyr' and 'dbplyr' for the final 'SQL' translation of the algorithm. It currently supports lm(), glm(), randomForest(), ranger(), earth(), xgb.Booster.complete(), cubist(), and ctree() models.
Authors: Edgar Ruiz [aut, cre], Max Kuhn [aut]
Maintainer: Edgar Ruiz <[email protected]>
License: MIT + file LICENSE
Version: 0.5
Built: 2024-11-18 03:56:00 UTC
Source: https://github.com/tidymodels/tidypredict

Help Index


Checks that the formula can be parsed

Description

Uses an S3 method to check that a given formula can be parsed based on its class. It currently scans for contrasts that are not supported and in-line functions. (e.g: lm(wt ~ as.factor(am))). Since this function is meant for function interaction, as opposed to human interaction, a successful check is silent.

Usage

acceptable_formula(model)

Arguments

model

An R model object

Examples

model <- lm(mpg ~ wt, mtcars)
acceptable_formula(model)

Prepares parsed model object

Description

Prepares parsed model object

Usage

as_parsed_model(x)

Arguments

x

A parsed model object


Converts an R model object into a table.

Description

It parses a fitted R model's structure and extracts the components needed to create a dplyr formula for prediction. The function also creates a data frame using a specific format so that other functions in the future can also pass parsed tables to a given formula creating function.

Usage

parse_model(model)

Arguments

model

An R model object.

Examples

library(dplyr)
df <- mutate(mtcars, cyl = paste0("cyl", cyl))
model <- lm(mpg ~ wt + cyl * disp, offset = am, data = df)
parse_model(model)

Tidy the parsed model results

Description

Tidy the parsed model results

Usage

## S3 method for class 'pm_regression'
tidy(x, ...)

Arguments

x

A parsed_model object

...

Reserved for future use


Returns a Tidy Eval formula to calculate fitted values

Description

It parses a model or uses an already parsed model to return a Tidy Eval formula that can then be used inside a dplyr command.

Usage

tidypredict_fit(model)

Arguments

model

An R model or a list with a parsed model.

Examples

model <- lm(mpg ~ wt + cyl * disp, offset = am, data = mtcars)
tidypredict_fit(model)

Returns a Tidy Eval formula to calculate prediction interval.

Description

It parses a model or uses an already parsed model to return a Tidy Eval formula that can then be used inside a dplyr command.

Usage

tidypredict_interval(model, interval = 0.95)

Arguments

model

An R model or a list with a parsed model

interval

The prediction interval, defaults to 0.95

Details

The result still has to be added to and subtracted from the fit to obtain the upper and lower bound respectively.

Examples

model <- lm(mpg ~ wt + cyl * disp, offset = am, data = mtcars)
tidypredict_interval(model)

Tests base predict function against tidypredict

Description

Compares the results of predict() and tidypredict_to_column() functions.

Usage

tidypredict_test(
  model,
  df = model$model,
  threshold = 1e-12,
  include_intervals = FALSE,
  max_rows = NULL,
  xg_df = NULL
)

Arguments

model

An R model or a list with a parsed model. It currently supports lm(), glm() and randomForest() models.

df

A data frame that contains all of the needed fields to run the prediction. It defaults to the "model" data frame object inside the model object.

threshold

The number that a given result difference, between predict() and tidypredict_to_column() should not exceed. For continuous predictions, the default value is 0.000000000001 (1e-12), and for categorical predictions, the default value is 0.

include_intervals

Switch to indicate if the prediction intervals should be included in the test. It defaults to FALSE.

max_rows

The number of rows in the object passed in the df argument. Highly recommended for large data sets.

xg_df

A xgb.DMatrix object, required only for XGBoost models. It defaults to NULL recommended for large data sets.

Examples

model <- lm(mpg ~ wt + cyl * disp, offset = am, data = mtcars)
tidypredict_test(model)

Adds the prediction columns to a piped command set.

Description

Adds a new column with the results from tidypredict_fit() to a piped command set. If add_interval is set to TRUE, it will add two additional columns- one for the lower and another for the upper prediction interval bounds.

Usage

tidypredict_to_column(
  df,
  model,
  add_interval = FALSE,
  interval = 0.95,
  vars = c("fit", "upper", "lower")
)

Arguments

df

A data.frame or tibble

model

An R model or a parsed model inside a data frame

add_interval

Switch that indicates if the prediction interval columns should be added. Defaults to FALSE

interval

The prediction interval, defaults to 0.95. Ignored if add_interval is set to FALSE

vars

The name of the variables that this function will produce. Defaults to "fit", "upper", and "lower".