add filters example

inst/examples/filters.R

@@ -0,0 +1,65 @@
+#!/usr/bin/env Rscript
+##
+## cf filters.cc
+##
+## When run, this program will create a 2D sparse array with each dimension
+## having separate datatypes, similar to a dataframe. It will write some data to
+## it, and read a slice of the data back.
+
+library(tiledb)
+
+## Name of the array to create.
+array_name <- "filters_array"
+
+## Path is either current directory, or a local config value is found
+uri <- file.path(getOption("TileDB_Data_Path", "."), array_name)
+
+create_array <- function(uri) {
+  ## The array will be 4x4 with dimensions "rows" and "cols"
+  ## "rows" is a string dimension type so domain and extend are NULL
+  ## and space tiles 2x2
+  dom <- tiledb_domain(dims = c(tiledb_dim("rows", c(1L,4L), 4L, "INT32"),
+                                tiledb_dim("cols", c(1L,4L), 4L, "INT32")))
+
+  ## Filters
+  fbwd <- tiledb_filter("BIT_WIDTH_REDUCTION")
+  fzstd <- tiledb_filter("ZSTD")
+  fla1 <- tiledb_filter_list(c(fbwd,fzstd))
+  fla2 <- tiledb_filter_list(tiledb_filter("GZIP"))
+
+  ## Sparse schema
+  schema <- tiledb_array_schema(dom,
+                                attrs = c(tiledb_attr("a1", type = "INT32", filter_list=fla1),
+                                          tiledb_attr("a2", type = "INT32", filter_list=fla2)),
+                                sparse = TRUE)
+
+  ## Create the (empty) array on disk.
+  tiledb_array_create(uri, schema)
+  invisible(NULL)
+}
+
+write_array <- function(uri) {
+  ## Write some simple data to cells (1, 1), (2, 4) and (2, 3).
+  data_a1 <- c(1L, 2L, 3L)
+  data_a2 <- c(-1L, -2L, -3L)
+  coords_rows <- c(1L, 2L, 2L)
+  coords_cols <- c(1L, 4L, 3L)
+
+  arr <- tiledb_array(uri, query_type="WRITE", is.sparse=TRUE)
+
+  arr[] <- data.frame(rows=coords_rows, cols=coords_cols, a1=data_a1, a2=data_a2)
+  invisible(NULL)
+}
+
+read_array <- function(uri) {
+  ## opening in data.frame mode; could also open with as.data.frame=FALSE
+  ## returning three vectors
+  arr <- tiledb_array(uri, as.data.frame=TRUE)
+  dat <- arr[]
+  print(dat)
+}
+
+if (dir.exists(uri)) unlink(uri, recursive=TRUE)
+create_array(uri)
+write_array(uri)
+read_array(uri)

inst/examples/quickstart_sparse_heter.R

@@ -1,6 +1,6 @@
 #!/usr/bin/env Rscript
 ##
-## cf quickstart_sparse_heter
+## cf quickstart_sparse_heter.cc
 ##
 ## When run, this program will create a 2D sparse array with each dimension
 ## having separate datatypes, similar to a dataframe. It will write some data to

inst/examples/quickstart_sparse_string.R

@@ -1,6 +1,6 @@
 #!/usr/bin/env Rscript
 ##
-## cf quickstart_sparse_string
+## cf quickstart_sparse_string.cc
 ##
 ## When run, this program will create a 2D sparse array with one dimension a
 ## string type, and the other an integer. This models closely what a dataframe