diff --git a/R/pkg/R/column.R b/R/pkg/R/column.R index 3095adb918b6..3d6d9f9746ee 100644 --- a/R/pkg/R/column.R +++ b/R/pkg/R/column.R @@ -164,12 +164,18 @@ setMethod("alias", #' @aliases substr,Column-method #' #' @param x a Column. -#' @param start starting position. +#' @param start starting position. It should be 1-base. #' @param stop ending position. +#' @examples +#' \dontrun{ +#' df <- createDataFrame(list(list(a="abcdef"))) +#' collect(select(df, substr(df$a, 1, 4))) # the result is `abcd`. +#' collect(select(df, substr(df$a, 2, 4))) # the result is `bcd`. +#' } #' @note substr since 1.4.0 setMethod("substr", signature(x = "Column"), function(x, start, stop) { - jc <- callJMethod(x@jc, "substr", as.integer(start - 1), as.integer(stop - start + 1)) + jc <- callJMethod(x@jc, "substr", as.integer(start), as.integer(stop - start + 1)) column(jc) }) diff --git a/R/pkg/tests/fulltests/test_sparkSQL.R b/R/pkg/tests/fulltests/test_sparkSQL.R index 5197838eaac6..bed26ec6a375 100644 --- a/R/pkg/tests/fulltests/test_sparkSQL.R +++ b/R/pkg/tests/fulltests/test_sparkSQL.R @@ -1649,6 +1649,7 @@ test_that("string operators", { expect_false(first(select(df, startsWith(df$name, "m")))[[1]]) expect_true(first(select(df, endsWith(df$name, "el")))[[1]]) expect_equal(first(select(df, substr(df$name, 1, 2)))[[1]], "Mi") + expect_equal(first(select(df, substr(df$name, 4, 6)))[[1]], "hae") if (as.numeric(R.version$major) >= 3 && as.numeric(R.version$minor) >= 3) { expect_true(startsWith("Hello World", "Hello")) expect_false(endsWith("Hello World", "a")) diff --git a/docs/sparkr.md b/docs/sparkr.md index 6685b585a393..2909247e79e9 100644 --- a/docs/sparkr.md +++ b/docs/sparkr.md @@ -663,3 +663,7 @@ You can inspect the search path in R with [`search()`](https://stat.ethz.ch/R-ma - The `stringsAsFactors` parameter was previously ignored with `collect`, for example, in `collect(createDataFrame(iris), stringsAsFactors = TRUE))`. It has been corrected. - For `summary`, option for statistics to compute has been added. Its output is changed from that from `describe`. - A warning can be raised if versions of SparkR package and the Spark JVM do not match. + +## Upgrading to Spark 2.4.0 + + - The `start` parameter of `substr` method was wrongly subtracted by one, previously. In other words, the index specified by `start` parameter was considered as 0-base. This can lead to inconsistent substring results and also does not match with the behaviour with `substr` in R. It has been fixed so the `start` parameter of `substr` method is now 1-base, e.g., therefore to get the same result as `substr(df$a, 2, 5)`, it should be changed to `substr(df$a, 1, 4)`.