H2O All Methods

• h2o.downloadCSV : Download a H2O dataset to a CSV file on a local disk.

• h2o.exportFile: ExpExport H2O Data Frame to a file

• h2o.importFile: Import a file from the local path and parse it.

• h2o.parseRaw: Parse a raw data file

• h2o.uploadFile: Upload a file from the local drive and parse it.

Native R to H2O Coercion

• as.h2o: Convert an R object to an H2O object.

H2O to Native R Coercion

• as.data.frame: Check if an object is a data frame, or coerce it if possible.

Data Generation

• h2o.createFrame: Create an H2O data frame, with optional

randomization.

• h2o.runif: Produce a vector of random uniform numbers.

• h2o.interaction: Create interaction terms between categorical features of an H2O Frame.

Data Sampling/Splitting

• h2o.splitFrame: Split an existing H2O dataset according to user-specified ratios.

Missing Data Handling

• h2o.impute: Impute a column of data using the mean, median, or mode.

• h2o.insertMissingValues: Replaces a user specified fraction of entries in a H2O dataset with missing values.

General Data Operations

• head, tail: Return the First or Last Part of an Object.

Math (H2O)

• abs: Compute the absolute value of x.

• sign: Return a vector with the signs of the corresponding elements of x (the sign of a real number is 1, 0, or -1 if the number is positive, zero, or negative, respectively).

• sqrt: Computes the principal square root of x, √x.

• ceiling: Take a single numeric argument x and return a numeric vector containing the smallest integers not less than the corresponding elements of x.

• floor: Take a single numeric argument x and return a numeric vector containing the largest integers not greater than the corresponding elements of x.

• trunc: Take a single numeric argument x and return a numeric vector containing the integers formed by truncating the values in x toward 0.

• log: Compute logarithms (by default, natural logarithms).

• exp: Compute the exponential function.

Math (generic)

• cummax: Display a vector of the cumulative maxima of the elements of the argument.

• cummin: Display a vector of the cumulative minima of the elements of the argument.

• cumprod: Display a vector of the cumulative products of the elements of the argument.

• log10: Compute common (i.e., base 10) logarithms

• log2: Compute binary (i.e., base 2) logarithms.

• log1p: Compute log(1+x) accurately also for |x|<< 1.

• acos: Compute the trigonometric arc-cosine.

• acosh: Compute the hyperbolic arc-cosine.

• asin: Compute the trigonometric arc-sine.

• asinh: Compute the hyperbolic arc-sine.

• atan: Compute the trigonometric arc-tangent.

• atanh: Compute the hyperbolic arc-tangent.

• expm1: Compute exp(x) - 1 accurately also for |x|<< 1.

• cos: Compute the trigonometric cosine.

• sinh: Compute the hyperbolic sine.

• sinpi: Compute the trigonometric two-argument arc-sine.

• tan: Compute the trigonometric tangent.

• tanh: Compute the hyperbolic tangent.

• tanpi: Compute the trigonometric two-argument arc-tangent.

• gamma: Display the gamma function γx

• lgamma: Display the natural logarithm of the absolute value of the gamma function.

• digamma: Display the first derivative of the logarithm of the gamma function.

• trigamma: Display the second derivative of the logarithm of the gamma function.

Math2 (H2O)

• round: Round the values to the specified number of decimal places. The default is 0.

• signif: Round the values to the specified number of significant digits.

Summary (H2O)

• max: Display the maximum of all the input arguments.
• min: Display the minimum of all the input arguments.
• range: Display a vector containing the minimum and maximum of all the given arguments.
• sum: Calculate the sum of all the values present in its arguments.

Summary (generic)

• prod: Display the product of all values present in its arguments.
• any: Given a set of logical vectors, determine if at least one of the values is true.
• all: Given a set of logical vectors, determine if all of the values are true.

Other Aggregations

Non-Group Generic Summaries

• mean: Generic function for the (trimmed) arithmetic mean.
• sd: Calculate the standard deviation of a column of continuous real valued data.
• var: Compute the variance of x.
• summary: Produce result summaries of the results of various model fitting functions.
• quantile: Obtain and display quantiles for H2O parsed data. Row / Column Aggregation
• apply: Apply a function over an H2O parsed data object (an array). Group By Aggregation
• h2o.group by: Apply an aggregate function to each group of an H2O dataset.

Tabulation

• h2o.table: Use the cross-classifying factors to build a table of counts at each combination of factor levels.

Data Munging

General Column Manipulations

• is.na: Display missing elements.

Element Index Selection

• h2o.which: Display the row numbers for which the condition is true.

Conditional Element Value Selection

• h2o.ifelse: Apply conditional statements to numeric vectors in H2O parsed data objects.

Numeric Column Manipulations

• h2o.cut: Convert H2O Numeric Data to Factor.

Character Column Manipulations

• h2o.strsplit: Splits the given factor column on the input split.
• h2o.tolower: Change the elements of a character vector to lower case.
• h2o.toupper: Change the elements of a character vector to lower case.
• h2o.trim: Remove leading and trailing white space.
• h2o.gsub: Match a pattern & replace all instances of the matched pattern with the replacement string globally.
• h2o.sub: Match a pattern & replace the first instance of the matched pattern with the replacement string.

Factor Level Manipulations

*h2o.levels: Display a list of the unique values found in a column of categorical data.

Date Manipulations

• h2o.month: Convert the entries of a H2OParsedData object from milliseconds to months (on a 0 to 11 scale).
• h2o.year: Convert the entries of a H2OParsedData object from milliseconds to years, indexed starting from 1900.

Matrix Operations

• %∗%: Multiply two matrices, if they are conformable.
• t: Given a matrix or data.frame x, t returns the transpose of x.

Data Modeling

Model Training: Supervised Learning

• h2o.deeplearning: Perform Deep Learning neural networks on an

• H2OParsedData object.

• h2o.gbm: Build gradient boosted classification trees and gradient boosted regression trees on a parsed dataset.

• h2o.glm: Fit a generalized linear model, specified by a response variable, a set of predictors, and a description of the error distribution.

• h2o.naiveBayes: Build gradient boosted classification trees and gradient boosted regression trees on a parsed dataset.

• h2o.prcomp: Perform principal components analysis on the given dataset.

• h2o.randomForest: Perform random forest classification on a dataset.

• h2o.xgboost: Build an extreme gradient boosted model.

Model Training: Unsupervised Learning

• h2o.anomaly: Detect anomalies in a H2O dataset using a H2O deep learning model with auto-encoding.
• h2o.deepfeatures: Extract the non-linear features from a H2O dataset using a H2O deep learning model.
• h2o.kmeans: Perform k-means clustering on a dataset.

Grid Search

• h2o.grid: Efficient method to build multiple models with different

hyperparameters.

Model Scoring

• h2o.predict: Obtain predictions from various fitted H2O model objects.

Model Metrics

• ho2.model metrics: Given predicted values (target for regression, class-1 probabilities, or binomial or per-class probabilities for multinomial), compute a model metrics object.

Classification Model Helpers

• h2o.accuracy: Get the between cluster sum of squares.
• h2o.auc: Retrieve the AUC (area under ROC curve).
• h2o.confusionMatrix: Display prediction errors for classification data from a column of predicted responses and a column of actual (reference) responses in H2O.
• h2o.hit ratio table: Retrieve the Hit Ratios. If train, valid, and xval parameters are FALSE (default), then the training Hit Ratios value is returned. If more than one parameter is seto TRUE, then a named list of Hit Ratio tables are returned, where the names are train, valid, or xval.
• h2o.performance: Evaluate the predictive performance of a model via various measures.

Regression Model Helper

• h2o.mse: Display the mean squared error calculated from a column of predicted responses and a column of actual (reference) responses in H2O.

Clustering Model Helper

• h2o.betweenss: Get the between cluster sum of squares.
• h2o.centers: Retrieve the Model Centers.

H2O Cluster Operations

H2O Key Value Store Access

• h2o.assign: Assign H2O hex.keys to objects in their R environment.
• h2o.getFrame: Get a reference to an existing H2O dataset.
• h2o.getModel: Get a reference to an existing H2O model.
• h2o.ls: Display a list of object keys in the running instance of H2O.
• h2o.rm: Remove H2O objects from the server where the instance of H2O is running, but does not remove it from the R environment.

H2O Object Serialization

h2o.loadModel: Load an H2OModel object from disk.

h2o.saveModel: Save an H2OModel object to disk to be loaded back into

H2O using h2o.loadModel.

H2O Cluster Connection

• h2o.init (nthreads = -1): Connect to a running H2O instance using all CPUs on the host and check the local H2O R package is the correct version.
• h2o.shutdown: Shut down the specified H2O instance. All data on the server will be lost!
• h2o.rebalance: Rebalance (repartition) an existing H2O dataset into given number of chunks (per Vec), for load-balancing across multiple threads or nodes.

H2O Cluster Information

• h2o.clusterInfo: Display the name, version, uptime, total nodes, total memory, total cores and health of a cluster running H2O.
• h2o.clusterStatus: Retrieve information on the status of the cluster running H2O.

H2O Logging

• h2o.clearLog: Clear all H2O R command and error response logs from the local disk.
• h2o.downloadAllLogs: Download all H2O log files to the local disk.
• h2o.logAndEcho: Write a message to the H2O Java log file and echo it back.
• h2o.openLog: Open existing logs of H2O R POST commands and error responses on the local disk.
• h2o.getLogPath: Get the file path for the H2O R command and error response logs.
• h2o.startLogging: Begin logging H2O R POST commands and error responses.
• h2o.stopLogging: Stop logging H2O R POST commands and error responses.

H2O String Manipulation

• h2o.gsub: String global substitution (all occurrences).
• h2o.strsplit: String Split.
• h2o.sub: String substitution (first occurrence).
• h2o.tolower: Convert characters to lower case.
• h2o.toupper: Convert characters to upper case.
• h2o.trim: Trim spaces.