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IOLink
IOL_v1.2.0_release
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IOLink
IOL_v1.2.0_release
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This class is used to index a classic array into a multi dimensional array. More...
#include <iolink/Indexer.h>
Public Member Functions | |
| Indexer (const VectorXu64 &shape, const VectorXu64 &stride, const VectorXu64 &layout) | |
| Create an indexer by giving all its informations. More... | |
| Indexer (const VectorXu64 &shape, const VectorXu64 &stride, MemoryLayout standardLayout) | |
| Create an indexer by giving all its informations. More... | |
| Indexer (const VectorXu64 &shape, const VectorXu64 &layout) | |
| Initialize the indexer using a custom memory layout. More... | |
| Indexer (const VectorXu64 &shape, MemoryLayout standardLayout) | |
| Auto compute the Indexer's strides from shape and standard layout. More... | |
| Indexer (const VectorXu64 &shape) | |
| Simpliest way to initialize an indexer from a shape. More... | |
| Indexer (const Indexer &other) | |
| Indexer & | operator= (const Indexer &other) |
| Indexer (Indexer &&other) noexcept | |
| Indexer & | operator= (Indexer &&other) noexcept |
| size_t | dimensionCount () const |
| The number of dimensions managed by this indexer. | |
| const VectorXu64 & | shape () const |
| Return the shape. | |
| const VectorXu64 & | stride () const |
| Return the stride. | |
| const VectorXu64 & | layout () const |
| Return the layout dimension order. | |
| size_t | shape (size_t index) const |
| Return the current size for given dimension. More... | |
| size_t | stride (size_t index) const |
| Return the current stride for given dimension. More... | |
| size_t | layout (size_t index) const |
| Return the dimension index of the nth one in order. More... | |
| size_t | elementCount () const |
| Returns the number of elements managed by this Indexer. | |
| size_t | offset (const VectorXu64 &index) const |
| Return the computed 1D offset corresponding to indexed sample in multi dimensional array. More... | |
This class is used to index a classic array into a multi dimensional array.
Its main use is to convert a multi-dimensional index into the corresponding offset in the flat array used for storage. An indexer contains all the needed tools and describes how the data is really stored. The three main elements are: the shape, the stride, and the layout.
The shape is simply the size of the indexed array in each dimension, for example an array with two columns and two rows will have a shape of {2, 2}.
The stride contains the offset between each iteration of a dimension, in elements. For example, our {2, 2} array will usually have a stride of {1, 2}, as each column element is adjacent (hence the stride of one), and when iterating element on a line, you must skip one element on the underlying array (hence the stride of 2). The stride dimension are in the same order as the shape, but they do not have to be in ascendent order. Actually, reverse order arrays (C convention) will have inversed strides, for example, {2, 1} in our {2, 2} array case.
The layout describes in wich order each dimension is ordered internally, and can be used to enhance performance. The usual IOLink layout is {0, 1, ..., n - 1, n}. As we use the Fortran convention in IOLink, indexing a C array would use an inverted layout {n, n-1, ..., 1, 0}. This field enables user to easily know how data is organised without analysing the strides directly.
| iolink::Indexer::Indexer | ( | const VectorXu64 & | shape, |
| const VectorXu64 & | stride, | ||
| const VectorXu64 & | layout | ||
| ) |
Create an indexer by giving all its informations.
Here all the arguments are given, and are not checked, so if they are not consistant, they will give an undefined behavior.
| shape | The shape of the array to index. |
| stride | The stride of each dimension, the offset in elements between each increment in this dimension. |
| layout | The internal order of dimensions, {0, 1} is row-major and {1, 0} is col-major for example. |
| iolink::Indexer::Indexer | ( | const VectorXu64 & | shape, |
| const VectorXu64 & | stride, | ||
| MemoryLayout | standardLayout | ||
| ) |
Create an indexer by giving all its informations.
Here all the arguments are given, and are not checked, so if they are not consistant, they will give an undefined behavior.
| shape | The shape of the array to index. |
| stride | The stride of each dimension, the offset in elements between each increment in this dimension. |
| standardLayout | A standard layout for the array. |
| Error | When the layout is unsupported |
| iolink::Indexer::Indexer | ( | const VectorXu64 & | shape, |
| const VectorXu64 & | layout | ||
| ) |
Initialize the indexer using a custom memory layout.
| shape | The shape of the indexed array |
| layout | The internal order of dimensions, {0, 1} is row-major and {1, 0} is col-major for example. |
| iolink::Indexer::Indexer | ( | const VectorXu64 & | shape, |
| MemoryLayout | standardLayout | ||
| ) |
|
explicit |
Simpliest way to initialize an indexer from a shape.
The layout here is Fortran one, and the strides are computed according to it.
| shape | The desired shape of the multi dimensional array. |
| size_t iolink::Indexer::layout | ( | size_t | index | ) | const |
Return the dimension index of the nth one in order.
| index | Index of the order dimension index. |
| size_t iolink::Indexer::offset | ( | const VectorXu64 & | index | ) | const |
Return the computed 1D offset corresponding to indexed sample in multi dimensional array.
| index | The element's position for which offset must be computed. |
| size_t iolink::Indexer::shape | ( | size_t | index | ) | const |
Return the current size for given dimension.
| index | Index of the dimension to consider |
| size_t iolink::Indexer::stride | ( | size_t | index | ) | const |
Return the current stride for given dimension.
| index | Index of the dimension to consider |
1.8.17