Package 'acane'

'Arrow C API' 'nanoarrow' Examples

Description

Programming via the C API of 'Arrow' is powerful, and while documentation exists additional examples should be helpful. Some examples are collected here.

Package Content

Index of help topics:

acane-package           'Arrow C API' 'nanoarrow' Examples
create_struct_example   create_struct_example
show_array              Display Arrow Structures Array or Schema

Maintainer

Dirk Eddelbuettel <[email protected]>

Author(s)

Dirk Eddelbuettel [aut, cre]

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create_struct_example

Description

Create a Simple ‘struct’ Arrow Object

Usage

create_struct_example()

Details

A two-column ‘struct’ is created and returned, containing respectively an integer and a floating point column each with one missing value

Value

A external pointer object is returned containing a pointer to the Arrow array with a pointer to the schema tucked away in the ‘tag’ component as is common for nanoarrow objects

Examples

s <- create_struct_example()
s                 # pretty-printed in full details thanks to 'nanoarrow' S3 methods
as.data.frame(s)  # converted thanks to 'nanoarrow' S3 methods

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Display Arrow Structures Array or Schema

Description

Helper functions showing elements of ‘Arrow Array’ or ‘Arrow Schema’ objects provided via an external pointer

Usage

show_array(sxparr)

show_schema(sxparr)

array_xptr_set_schema(array_xptr, schema_xptr)

array_xptr_get_schema(array_xptr)

Arguments

sxparr	An external pointer to an ‘Arrow Array’ also containing a pointer to the corresponding ‘Arrow Schema’ in its ‘tag’ slot
array_xptr	A external pointer to an Arrow array data structure
schema_xptr	A external pointer to an Arrow schema data structure

Value

Nothing is returned, the functions are invoked for the side effect of printing

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