Chi-square hypothesis testing for categorical data.

Conduct Pearson's independence test for every feature against the label. For each feature, the (feature, label) pairs are converted into a contingency matrix for which the Chi-squared statistic is computed. All label and feature values must be categorical.

ml_chisquare_test(x, features, label)

Arguments

x

A tbl_spark.

features

The name(s) of the feature columns. This can also be the name of a single vector column created using ft_vector_assembler().

label

The name of the label column.

Value

A data frame with one row for each (feature, label) pair with p-values, degrees of freedom, and test statistics.

Examples

if (FALSE) { sc <- spark_connect(master = "local") iris_tbl <- sdf_copy_to(sc, iris, name = "iris_tbl", overwrite = TRUE) features <- c("Petal_Width", "Petal_Length", "Sepal_Length", "Sepal_Width") ml_chisquare_test(iris_tbl, features = features, label = "Species") }