ml_svm_linear: Linear SVM Model

In danzafar/tidyspark: A Tidy Interface to Spark

Description

Fits a linear SVM model against a spark_tbl, similar to svm in e1071 package. Currently only supports binary classification model with linear kernel. Users can print, make predictions on the produced model and save the model to the input path.

Usage

ml_svm_linear(
  data,
  formula,
  regParam = 0,
  maxIter = 100,
  tol = 1e-06,
  standardization = TRUE,
  threshold = 0,
  weightCol = NULL,
  aggregationDepth = 2,
  handleInvalid = c("error", "keep", "skip")
)

## S4 method for signature 'LinearSVCModel'
predict(object, newData)

## S4 method for signature 'LinearSVCModel'
summary(object)

## S4 method for signature 'LinearSVCModel,character'
write_ml(object, path, overwrite = FALSE)

Arguments

data	spark_tbl for training.
formula	A symbolic description of the model to be fitted. Currently only a few formula operators are supported, including '~', '.', ':', '+', '-', '*', and '^'.
regParam	The regularization parameter. Only supports L2 regularization currently.
maxIter	Maximum iteration number.
tol	Convergence tolerance of iterations.
standardization	Whether to standardize the training features before fitting the model. The coefficients of models will be always returned on the original scale, so it will be transparent for users. Note that with/without standardization, the models should be always converged to the same solution when no regularization is applied.
threshold	The threshold in binary classification applied to the linear model prediction. This threshold can be any real number, where Inf will make all predictions 0.0 and -Inf will make all predictions 1.0.
weightCol	The weight column name.
aggregationDepth	The depth for treeAggregate (greater than or equal to 2). If the dimensions of features or the number of partitions are large, this param could be adjusted to a larger size. This is an expert parameter. Default value should be good for most cases.
handleInvalid	How to handle invalid data (unseen labels or NULL values) in features and label column of string type. Supported options: "skip" (filter out rows with invalid data), "error" (throw an error), "keep" (put invalid data in a special additional bucket, at index numLabels). Default is "error".
object	a LinearSVCModel fitted by ml_svm_linear.
newData	a spark_tbl for testing.
path	The directory where the model is saved.
overwrite	Overwrites or not if the output path already exists. Default is FALSE which means throw exception if the output path exists.
...	additional arguments passed to the method.

Value

ml_svm_linear returns a fitted linear SVM model.

predict returns the predicted values based on a LinearSVCModel.

summary returns summary information of the fitted model, which is a list. The list includes coefficients (coefficients of the fitted model), numClasses (number of classes), numFeatures (number of features).

Note

ml_svm_linear since 2.2.0

predict(LinearSVCModel) since 2.2.0

summary(LinearSVCModel) since 2.2.0

write_ml(LogisticRegression, character) since 2.2.0

Examples

## Not run: 
spark_session()
t <- as.data.frame(Titanic)
training <- spark_tbl(t)
model <- ml_svm_linear(training, Survived ~ ., regParam = 0.5)
summary <- summary(model)

# fitted values on training data
fitted <- predict(model, training)

# save fitted model to input path
path <- "path/to/model"
write_ml(model, path)

# can also read back the saved model and predict
# Note that summary deos not work on loaded model
savedModel <- read_ml(path)
summary(savedModel)

## End(Not run)

danzafar/tidyspark documentation built on Sept. 30, 2020, 12:19 p.m.