hof_transform_values
Transforms values of a map
Description
Applies the transformation function specified to all values of a map (this is essentially a dplyr wrapper to the transform_values(expr, func) higher- order function, which is supported since Spark 3.0)
Usage
hof_transform_values(x, func, expr = NULL, dest_col = NULL, ...)Arguments
| Argument | Description |
|---|---|
| x | The Spark data frame to be processed |
| func | The transformation function to apply (it should take (key, value) as |
arguments and return a transformed value) expr | The map being transformed, could be any SQL expression evaluating to a map (default: the last column of the Spark data frame) dest_col | Column to store the transformed result (default: expr) … | Additional params to dplyr::mutate
Examples
library(sparklyr)
sc <- spark_connect(master = "local", version = "3.0.0")
sdf <- sdf_len(sc, 1) %>% dplyr::mutate(m = map("a", 0L, "b", 2L, "c", -1L))
transformed_sdf <- sdf %>% hof_transform_values(~ CONCAT(.x, " == ", .y))