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Confusion matrix for LDA / QDA

Source: R/confusion.R
confusion.Rd

Calculates a table of the actual vs. predicted class of all observations in a dataset for objects resulting from MASS::lda() or MASS::qda()

Usage

confusion(object, ...)

# S3 method for class 'lda'
confusion(object, ...)

# S3 method for class 'qda'
confusion(object, ...)

# S3 method for class 'confusion'
print(x, digits = 2, ...)

Arguments

object

An object of class lda or qda

...

Arguments passed to methods

x

A confusion object

digits

Number of decimal places for accuracy and error rates

Value

An object of class c("confusion", "table"), a table of frequencies of actual vs. predicted class with attributes accuracy and error giving the overall rates of correct and incorrect prediction.

See also

MASS::lda(), MASS::qda()

Examples


library(MASS)
#> 
#> Attaching package: 'MASS'
#> The following object is masked from 'package:dplyr':
#> 
#>     select
iris.lda <- lda(Species ~ ., iris)
confusion(iris.lda)
#>             predicted
#> actual       setosa versicolor virginica
#>   setosa         50          0         0
#>   versicolor      0         48         2
#>   virginica       0          1        49
#> 
#> Accuracy:  98.00%
#> Error:      2.00%

iris.qda <- qda(Species ~ ., iris)
confusion(iris.qda)
#>             predicted
#> actual       setosa versicolor virginica
#>   setosa         50          0         0
#>   versicolor      0         48         2
#>   virginica       0          1        49
#> 
#> Accuracy:  98.00%
#> Error:      2.00%