Classification of multivariate observations by semi-supervised Gaussian finite mixtures

Classify multivariate observations based on Gaussian finite mixture models estimated by MclustSSC.

Usage

# S3 method for MclustSSC
predict(object, newdata, ...)

Arguments

object

an object of class 'MclustSSC' resulting from a call to MclustSSC.

newdata

a data frame or matrix giving the data. If missing the train data obtained from the call to MclustSSC are classified.

...

further arguments passed to or from other methods.

Value

Returns a list of with the following components:

classification

a factor of predicted class labels for newdata.

z

a matrix whose [i,k]th entry is the probability that observation i in newdata belongs to the kth class.

Author

Luca Scrucca

See also

MclustSSC.

Examples

# \donttest{
X <- iris[,1:4]
class <- iris$Species
# randomly remove class labels
set.seed(123)
class[sample(1:length(class), size = 120)] <- NA
table(class, useNA = "ifany")
#> class
#>     setosa versicolor  virginica       <NA> 
#>         10         15          5        120 
clPairs(X, ifelse(is.na(class), 0, class),
        symbols = c(0, 16, 17, 18), colors = c("grey", 4, 2, 3),
        main = "Partially classified data")


# Fit semi-supervised classification model
mod_SSC  <- MclustSSC(X, class)

pred_SSC <- predict(mod_SSC)
table(Predicted = pred_SSC$classification, Actual = class, useNA = "ifany")
#>             Actual
#> Predicted    setosa versicolor virginica <NA>
#>   setosa         10          0         0   40
#>   versicolor      0         15         0   45
#>   virginica       0          0         5   35

X_new = data.frame(Sepal.Length = c(5, 8),
                   Sepal.Width  = c(3.1, 4),
                   Petal.Length = c(2, 5),
                   Petal.Width  = c(0.5, 2))
predict(mod_SSC, newdata = X_new)
#> $classification
#> [1] setosa     versicolor
#> Levels: setosa versicolor virginica
#> 
#> $z
#>             setosa   versicolor    virginica
#> [1,]  9.999995e-01 4.732013e-07 2.971005e-24
#> [2,] 1.919741e-120 9.996956e-01 3.044061e-04
#> 
# }