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Create a SOMA Data Frame

Source: R/Factory.R
SOMADataFrameCreate.Rd

Factory function to create a SOMA data frame for writing (lifecycle: maturing).

Usage

SOMADataFrameCreate(
  uri,
  schema,
  index_column_names = c("soma_joinid"),
  domain = NULL,
  ingest_mode = c("write", "resume"),
  platform_config = NULL,
  tiledbsoma_ctx = NULL,
  tiledb_timestamp = NULL,
  soma_context = NULL
)

Arguments

uri

URI for the TileDB object.

schema

Arrow schema argument for the SOMA dataframe.

index_column_names

A vector of column names to use as user-defined index columns; all named columns must exist in the schema, and at least one index column name is required.

domain

An optional list of 2-element vectors specifying the domain of each index column. Each vector should be a pair consisting of the minimum and maximum values storable in the index column. For example, if there is a single int64-valued index column, then domain might be c(100, 200) to indicate that values between 100 and 200, inclusive, can be stored in that column. If provided, this list must have the same length as index_column_names, and the index-column domain will be as specified. If omitted entirely, or if NULL in a given dimension, the corresponding index-column domain will use the minimum and maximum possible values for the column's datatype. This makes a SOMA data frame growable.

ingest_mode

Ingestion mode when creating the TileDB object; choose from:

  • “write”: create a new TileDB object and error if it already exists.

  • “resume”: attempt to create a new TileDB object; if it already exists, simply open it for writing.

platform_config

Optional platform configuration.

tiledbsoma_ctx

Optional SOMATileDBContext.

tiledb_timestamp

Optional Datetime (POSIXct) for TileDB timestamp.

soma_context

A SOMA context as created by soma_context().

Value

A new SOMA data frame stored at uri opened for writing.

Examples

uri <- withr::local_tempfile(pattern = "soma-data-frame")
df <- data.frame(
  soma_joinid = bit64::seq.integer64(0L, 99L),
  group = sample(factor(c("g1", "g2")), size = 100L, replace = TRUE),
  nCount = stats::rbinom(100L, 10L, 0.3)
)
(sch <- arrow::infer_schema(df))
#> Schema
#> soma_joinid: int64
#> group: dictionary<values=string, indices=int8>
#> nCount: int32
(sdf <- SOMADataFrameCreate(uri, sch, domain = list(soma_joinid = c(0, 100))))
#> <SOMADataFrame>
#>   uri: /tmp/RtmpjD0Pq2/soma-data-frame2709fd40fff
#>   dimensions: soma_joinid 
#>   attributes: group, nCount 
sdf$write(arrow::as_arrow_table(df, schema = sch))
sdf$close()

(sdf <- SOMADataFrameOpen(uri))
#> <SOMADataFrame>
#>   uri: /tmp/RtmpjD0Pq2/soma-data-frame2709fd40fff
#>   dimensions: soma_joinid 
#>   attributes: group, nCount 
head(as.data.frame(sdf$read()$concat()))
#>   soma_joinid group nCount
#> 1           0    g1      1
#> 2           1    g1      4
#> 3           2    g1      2
#> 4           3    g2      0
#> 5           4    g1      1
#> 6           5    g1      4