The “h2o.merge” Function in R

• Package: h2o

• Purpose: To merge two H2O data frames by common column names.

• General Class: Data Manipulation

• Required Argument(s):

• x: H2OFrame. The first H2O data frame to merge.

• y: H2OFrame. The second H2O data frame to merge.

• Notable Optional Arguments:

• all.x: Logical. If TRUE, include all rows from x. The default is FALSE.

• all.y: Logical. If TRUE, include all rows from y. The default is FALSE.

• by: Character vector. The names of the columns to merge by. If NULL, merge on common column names.

• by.x: Character vector. The names of the columns in x to merge by. If NULL, merge on common column names.

• by.y: Character vector. The names of the columns in y to merge by. If NULL, merge on common column names.

• Example (with Explanation):

• # Load necessary package
  library(h2o)
  
  # Initialize H2O
  h2o.init()
  
  # Modified iris data that adds a fictitious day the data points were collected on
  modified_iris <- data.frame(Day = as.factor(rep(paste("Day_",1:75,sep=""),2)), iris)
  names(modified_iris) <- c("Day","SL","SW","PL","PW","Spec") # Changed to improve printing
  
  # Create two H2OFrames
  data1 <- as.h2o(modified_iris[1:75, ])
  data2 <- as.h2o(modified_iris[76:150, ])
  
  # Merge the two data frames by data collection day (2 points per day)
  merged_data <- h2o.merge(x = data1, y = data2, by = "Day")
  
  # View the merged data
  print(merged_data)

• In this example, the h2o.merge function from the h2o package is used to merge two H2O data frames (data1 and data2) by the fictitious day the data was collected. By default, the function merges on common column names. After merging, the resulting data frame merged_data contains the combined data from both input data frames.