convert_array_stream {nanoarrow}

Convert an Array Stream into an R vector

Description

Converts array_stream to the type specified by to. This is a low-level interface; most users should use as.data.frame() or as.vector() unless finer-grained control is needed over the conversion. See convert_array() for details of the conversion process; see infer_nanoarrow_ptype() for default inferences of to.

Usage

convert_array_stream(array_stream, to = NULL, size = NULL, n = Inf)

collect_array_stream(array_stream, n = Inf, schema = NULL, validate = TRUE)

Arguments

array_stream

A nanoarrow_array_stream.

to

A target prototype object describing the type to which array should be converted, or NULL to use the default conversion as returned by infer_nanoarrow_ptype(). Alternatively, a function can be passed to perform an alternative calculation of the default ptype as a function of array and the default inference of the prototype.

size

The exact size of the output, if known. If specified, slightly more efficient implementation may be used to collect the output.

n

The maximum number of batches to pull from the array stream.

schema

A nanoarrow_schema or NULL to guess based on the first schema.

validate

Use FALSE to skip the validation step (i.e., if you know that the arrays are valid).

Value

• convert_array_stream(): An R vector of type to.

• collect_array_stream(): A list() of nanoarrow_array

Examples

stream <- as_nanoarrow_array_stream(data.frame(x = 1:5))
str(convert_array_stream(stream))
str(convert_array_stream(stream, to = data.frame(x = double())))

stream <- as_nanoarrow_array_stream(data.frame(x = 1:5))
collect_array_stream(stream)