Slicing

Files
file	copying.hpp
	Column APIs for gather, scatter, split, slice, etc.

Functions
std::vector< column_view >	cudf::slice (column_view const &input, host_span< size_type const > indices)
	Slices a column_view into a set of column_views according to a set of indices. More...
std::vector< column_view >	cudf::slice (column_view const &input, std::initializer_list< size_type > indices)
	Slices a column_view into a set of column_views according to a set of indices. More...
std::vector< table_view >	cudf::slice (table_view const &input, host_span< size_type const > indices)
	Slices a table_view into a set of table_views according to a set of indices. More...
std::vector< table_view >	cudf::slice (table_view const &input, std::initializer_list< size_type > indices)
	Slices a table_view into a set of table_views according to a set of indices. More...

Detailed Description

Function Documentation

slice() [1/4]

std::vector<column_view> cudf::slice	(	column_view const &	input,
		host_span< size_type const >	indices
	)

Slices a column_view into a set of column_views according to a set of indices.

The returned views of input are constructed from an even number indices where the ith returned column_view views the elements in input indicated by the range [indices[2*i], indices[(2*i)+1]).

For all i it is expected indices[i] <= input.size() For all i%2==0, it is expected that indices[i] <= indices[i+1]

Note

It is the caller's responsibility to ensure that the returned views do not outlive the viewed device memory.

input:   {10, 12, 14, 16, 18, 20, 22, 24, 26, 28}
indices: {1, 3, 5, 9, 2, 4, 8, 8}
output:  {{12, 14}, {20, 22, 24, 26}, {14, 16}, {}}

Exceptions

cudf::logic_error	if indices size is not even.
cudf::logic_error	When the values in the pair are strictly decreasing.
cudf::logic_error	When any of the values in the pair don't belong to the range [0, input.size()).

Parameters

input	View of column to slice
indices	Indices used to take slices of input

Returns

Vector of views of input indicated by the ranges in indices

slice() [2/4]

std::vector<column_view> cudf::slice	(	column_view const &	input,
		std::initializer_list< size_type >	indices
	)

Slices a column_view into a set of column_views according to a set of indices.

The returned views of input are constructed from an even number indices where the ith returned column_view views the elements in input indicated by the range [indices[2*i], indices[(2*i)+1]).

For all i it is expected indices[i] <= input.size() For all i%2==0, it is expected that indices[i] <= indices[i+1]

Note

It is the caller's responsibility to ensure that the returned views do not outlive the viewed device memory.

input:   {10, 12, 14, 16, 18, 20, 22, 24, 26, 28}
indices: {1, 3, 5, 9, 2, 4, 8, 8}
output:  {{12, 14}, {20, 22, 24, 26}, {14, 16}, {}}

Exceptions

cudf::logic_error	if indices size is not even.
cudf::logic_error	When the values in the pair are strictly decreasing.
cudf::logic_error	When any of the values in the pair don't belong to the range [0, input.size()).

Parameters

input	View of column to slice
indices	Indices used to take slices of input

Returns

Vector of views of input indicated by the ranges in indices

slice() [3/4]

std::vector<table_view> cudf::slice	(	table_view const &	input,
		host_span< size_type const >	indices
	)

Slices a table_view into a set of table_views according to a set of indices.

The returned views of input are constructed from an even number indices where the ith returned table_view views the elements in input indicated by the range [indices[2*i], indices[(2*i)+1]).

For all i it is expected indices[i] <= input.size() For all i%2==0, it is expected that indices[i] <= indices[i+1]

Note

It is the caller's responsibility to ensure that the returned views do not outlive the viewed device memory.

input:   [{10, 12, 14, 16, 18, 20, 22, 24, 26, 28},
          {50, 52, 54, 56, 58, 60, 62, 64, 66, 68}]
indices: {1, 3, 5, 9, 2, 4, 8, 8}
output:  [{{12, 14}, {20, 22, 24, 26}, {14, 16}, {}},
          {{52, 54}, {60, 22, 24, 26}, {14, 16}, {}}]

Exceptions

cudf::logic_error	if indices size is not even.
cudf::logic_error	When the values in the pair are strictly decreasing.
cudf::logic_error	When any of the values in the pair don't belong to the range [0, input.size()).

Parameters

input	View of table to slice
indices	Indices used to take slices of input

Returns

Vector of views of input indicated by the ranges in indices

slice() [4/4]

std::vector<table_view> cudf::slice	(	table_view const &	input,
		std::initializer_list< size_type >	indices
	)

Slices a table_view into a set of table_views according to a set of indices.

The returned views of input are constructed from an even number indices where the ith returned table_view views the elements in input indicated by the range [indices[2*i], indices[(2*i)+1]).

For all i it is expected indices[i] <= input.size() For all i%2==0, it is expected that indices[i] <= indices[i+1]

Note

It is the caller's responsibility to ensure that the returned views do not outlive the viewed device memory.

input:   [{10, 12, 14, 16, 18, 20, 22, 24, 26, 28},
          {50, 52, 54, 56, 58, 60, 62, 64, 66, 68}]
indices: {1, 3, 5, 9, 2, 4, 8, 8}
output:  [{{12, 14}, {20, 22, 24, 26}, {14, 16}, {}},
          {{52, 54}, {60, 22, 24, 26}, {14, 16}, {}}]

Exceptions

cudf::logic_error	if indices size is not even.
cudf::logic_error	When the values in the pair are strictly decreasing.
cudf::logic_error	When any of the values in the pair don't belong to the range [0, input.size()).

Parameters

input	View of table to slice
indices	Indices used to take slices of input

Returns

Vector of views of input indicated by the ranges in indices