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Convert an Arrow table to a data frame, keeping decimal columns exact

Source: R/arrow.R
arrow_as_data_frame.Rd

as.data.frame() on an Arrow Table or RecordBatch converts a plain decimal field through double, which silently drops digits beyond the seventeenth. arrow_as_data_frame() converts those fields with as_decimal() instead, so they arrive as decimal vectors with the scale declared by their Arrow type. Every other column, including decimal columns this package wrote as its extension type, is converted by arrow in the usual way.

Usage

arrow_as_data_frame(x)

Arguments

x

An Arrow Table or RecordBatch.

Value

A data frame whose decimal columns are decimal vectors.

See also

decimal_arrow for when a decimal field is plain and when it is the extension type.

Examples

if (requireNamespace("arrow", quietly = TRUE)) {
  tab <- arrow::arrow_table(
    id = 1:2,
    amount = arrow::Array$create(
      c("100.05", "99999999999999999999.99")
    )$cast(arrow::decimal128(25, 2))
  )
  arrow_as_data_frame(tab)
}
#>   id                  amount
#> 1  1                  100.05
#> 2  2 99999999999999999999.99