Modules | Files | Enumerations | Functions

Modules

 Transpose
 

Files

file  explode.hpp
 Column APIs for explore list columns.
 
file  reshape.hpp
 Column APIs for interleave and tile.
 

Enumerations

enum  cudf::flip_endianness : bool { NO, YES }
 Configures whether byte casting flips endianness.
 

Functions

std::unique_ptr< tablecudf::explode (table_view const &input_table, size_type explode_column_idx, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
 Explodes a list column's elements. More...
 
std::unique_ptr< tablecudf::explode_position (table_view const &input_table, size_type explode_column_idx, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
 Explodes a list column's elements and includes a position column. More...
 
std::unique_ptr< tablecudf::explode_outer (table_view const &input_table, size_type explode_column_idx, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
 Explodes a list column's elements retaining any null entries or empty lists inside. More...
 
std::unique_ptr< tablecudf::explode_outer_position (table_view const &input_table, size_type explode_column_idx, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
 Explodes a list column's elements retaining any null entries or empty lists and includes a position column. More...
 
std::unique_ptr< columncudf::interleave_columns (table_view const &input, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
 Interleave columns of a table into a single column. More...
 
std::unique_ptr< tablecudf::tile (table_view const &input, size_type count, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
 Repeats the rows from input table count times to form a new table. More...
 
std::unique_ptr< columncudf::byte_cast (column_view const &input_column, flip_endianness endian_configuration, rmm::mr::device_memory_resource *mr=rmm::mr::get_current_device_resource())
 Converts a column's elements to lists of bytes. More...
 

Detailed Description

Function Documentation

◆ byte_cast()

std::unique_ptr<column> cudf::byte_cast ( column_view const &  input_column,
flip_endianness  endian_configuration,
rmm::mr::device_memory_resource mr = rmm::mr::get_current_device_resource() 
)

Converts a column's elements to lists of bytes.

input<int32> = [8675, 309]
configuration = flip_endianness::YES
return = [[0x00, 0x00, 0x21, 0xe3], [0x00, 0x00, 0x01, 0x35]]
Parameters
input_columnColumn to be converted to lists of bytes.
endian_configurationWhether to retain or flip the endianness of the elements.
mrDevice memory resource used to allocate the returned column's device memory.
Returns
The column containing the lists of bytes.

◆ explode()

std::unique_ptr<table> cudf::explode ( table_view const &  input_table,
size_type  explode_column_idx,
rmm::mr::device_memory_resource mr = rmm::mr::get_current_device_resource() 
)

Explodes a list column's elements.

Any list is exploded, which means the elements of the list in each row are expanded into new rows in the output. The corresponding rows for other columns in the input are duplicated. Example:

[[5,10,15], 100],
[[20,25], 200],
[[30], 300],
returns
[5, 100],
[10, 100],
[15, 100],
[20, 200],
[25, 200],
[30, 300],

Nulls and empty lists propagate in different ways depending on what is null or empty.

[[5,null,15], 100],
[null, 200],
[[], 300],
returns
[5, 100],
[null, 100],
[15, 100],

Note that null lists are not included in the resulting table, but nulls inside lists and empty lists will be represented with a null entry for that column in that row.

Parameters
input_tableTable to explode.
explode_column_idxColumn index to explode inside the table.
mrDevice memory resource used to allocate the returned column's device memory.
Returns
A new table with explode_col exploded.

◆ explode_outer()

std::unique_ptr<table> cudf::explode_outer ( table_view const &  input_table,
size_type  explode_column_idx,
rmm::mr::device_memory_resource mr = rmm::mr::get_current_device_resource() 
)

Explodes a list column's elements retaining any null entries or empty lists inside.

Any list is exploded, which means the elements of the list in each row are expanded into new rows in the output. The corresponding rows for other columns in the input are duplicated. Example:

[[5,10,15], 100],
[[20,25], 200],
[[30], 300],
returns
[5, 100],
[10, 100],
[15, 100],
[20, 200],
[25, 200],
[30, 300],

Nulls and empty lists propagate as null entries in the result.

[[5,null,15], 100],
[null, 200],
[[], 300],
returns
[5, 100],
[null, 100],
[15, 100],
[null, 200],
[null, 300],
Parameters
input_tableTable to explode.
explode_column_idxColumn index to explode inside the table.
mrDevice memory resource used to allocate the returned column's device memory.
Returns
A new table with explode_col exploded.

◆ explode_outer_position()

std::unique_ptr<table> cudf::explode_outer_position ( table_view const &  input_table,
size_type  explode_column_idx,
rmm::mr::device_memory_resource mr = rmm::mr::get_current_device_resource() 
)

Explodes a list column's elements retaining any null entries or empty lists and includes a position column.

Any list is exploded, which means the elements of the list in each row are expanded into new rows in the output. The corresponding rows for other columns in the input are duplicated. A position column is added that has the index inside the original list for each row. Example:

[[5,10,15], 100],
[[20,25], 200],
[[30], 300],
returns
[0, 5, 100],
[1, 10, 100],
[2, 15, 100],
[0, 20, 200],
[1, 25, 200],
[0, 30, 300],

Nulls and empty lists propagate as null entries in the result.

[[5,null,15], 100],
[null, 200],
[[], 300],
returns
[0, 5, 100],
[1, null, 100],
[2, 15, 100],
[0, null, 200],
[0, null, 300],
Parameters
input_tableTable to explode.
explode_column_idxColumn index to explode inside the table.
mrDevice memory resource used to allocate the returned column's device memory.
Returns
A new table with explode_col exploded.

◆ explode_position()

std::unique_ptr<table> cudf::explode_position ( table_view const &  input_table,
size_type  explode_column_idx,
rmm::mr::device_memory_resource mr = rmm::mr::get_current_device_resource() 
)

Explodes a list column's elements and includes a position column.

Any list is exploded, which means the elements of the list in each row are expanded into new rows in the output. The corresponding rows for other columns in the input are duplicated. A position column is added that has the index inside the original list for each row. Example:

[[5,10,15], 100],
[[20,25], 200],
[[30], 300],
returns
[0, 5, 100],
[1, 10, 100],
[2, 15, 100],
[0, 20, 200],
[1, 25, 200],
[0, 30, 300],

Nulls and empty lists propagate in different ways depending on what is null or empty.

[[5,null,15], 100],
[null, 200],
[[], 300],
returns
[0, 5, 100],
[1, null, 100],
[2, 15, 100],

Note that null lists are not included in the resulting table, but nulls inside lists and empty lists will be represented with a null entry for that column in that row.

Parameters
input_tableTable to explode.
explode_column_idxColumn index to explode inside the table.
mrDevice memory resource used to allocate the returned column's device memory.
Returns
A new table with exploded value and position. The column order of return table is [cols before explode_input, explode_position, explode_value, cols after explode_input].

◆ interleave_columns()

std::unique_ptr<column> cudf::interleave_columns ( table_view const &  input,
rmm::mr::device_memory_resource mr = rmm::mr::get_current_device_resource() 
)

Interleave columns of a table into a single column.

Converts the column major table input into a row major column. Example:

in = [[A1, A2, A3], [B1, B2, B3]]
return = [A1, B1, A2, B2, A3, B3]
Exceptions
cudf::logic_errorif input contains no columns.
cudf::logic_errorif input columns dtypes are not identical.
Parameters
[in]inputTable containing columns to interleave.
[in]mrDevice memory resource used to allocate the returned column's device memory
Returns
The interleaved columns as a single column

◆ tile()

std::unique_ptr<table> cudf::tile ( table_view const &  input,
size_type  count,
rmm::mr::device_memory_resource mr = rmm::mr::get_current_device_resource() 
)

Repeats the rows from input table count times to form a new table.

output.num_columns() == input.num_columns() output.num_rows() == input.num_rows() * count

input = [[8, 4, 7], [5, 2, 3]]
count = 2
return = [[8, 4, 7, 8, 4, 7], [5, 2, 3, 5, 2, 3]]
Parameters
[in]inputTable containing rows to be repeated.
[in]countNumber of times to tile "rows". Must be non-negative.
[in]mrDevice memory resource used to allocate the returned table's device memory
Returns
The table containing the tiled "rows".