accuracy function

Accuracy

Accuracy is the proportion of the data that are predicted correctly.

accuracy(data, ...)

## S3 method for class 'data.frame'
accuracy(data, truth, estimate, na_rm = TRUE, case_weights = NULL, ...)

accuracy_vec(truth, estimate, na_rm = TRUE, case_weights = NULL, ...)

Arguments

• data: Either a data.frame containing the columns specified by the truth and estimate arguments, or a table/matrix where the true class results should be in the columns of the table.

• ...: Not currently used.

• truth: The column identifier for the true class results (that is a factor). This should be an unquoted column name although this argument is passed by expression and supports quasiquotation (you can unquote column names). For _vec() functions, a factor vector.

• estimate: The column identifier for the predicted class results (that is also factor). As with truth this can be specified different ways but the primary method is to use an unquoted variable name. For _vec() functions, a factor vector.

• na_rm: A logical value indicating whether NA

  values should be stripped before the computation proceeds.

• case_weights: The optional column identifier for case weights. This should be an unquoted column name that evaluates to a numeric column in data. For _vec() functions, a numeric vector, hardhat::importance_weights(), or hardhat::frequency_weights().

Returns

A tibble with columns .metric, .estimator, and .estimate and 1 row of values.

For grouped data frames, the number of rows returned will be the same as the number of groups.

For accuracy_vec(), a single numeric value (or NA).

Multiclass

Accuracy extends naturally to multiclass scenarios. Because of this, macro and micro averaging are not implemented.

Examples

library(dplyr)
data("two_class_example")
data("hpc_cv")

# Two class
accuracy(two_class_example, truth, predicted)

# Multiclass
# accuracy() has a natural multiclass extension
hpc_cv %>%
  filter(Resample == "Fold01") %>%
  accuracy(obs, pred)

# Groups are respected
hpc_cv %>%
  group_by(Resample) %>%
  accuracy(obs, pred)

See Also

Other class metrics: bal_accuracy(), detection_prevalence(), f_meas(), j_index(), kap(), mcc(), npv(), ppv(), precision(), recall(), sens(), spec()

Author(s)

Max Kuhn