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rh2o

How to create new column in H2OFrame

I have a H2OFrame with two columns and I want to create new column, which is calculated from existing columns (sum of existing columns). How can I create new column in H2OFrame (like mutate() in dplyr) without converting H2OFrame to another frame? Is there any H2O R function doing this?

data <- data.frame(X = c(10, 20),
                   Y = c(30, 40))

library(h2o)
h2o.init()

data.hex <- as.h2o(data)
data.hex

How could I create output (Z = X + Y)?

   X  Y  Z
1 10 30 40
2 20 40 60
Solution

  • As usual in R you can create/modify columns of a data.frame with using the the assignment operator <-.

    data.hex$Z <- data.hex$X + data.hex$Y
data.hex

   X  Y  Z
1 10 30 40
2 20 40 60

[2 rows x 3 columns]

    Since a data.frame is nothing else then a list, you can also use list indexing for this.

    data.hex[["Z"]] <- data.hex[["X"]] + data.hex[["Y"]]
data.hex

   X  Y  Z
1 10 30 40
2 20 40 60