Tensor

Defined in coo.hpp

template<class Label = uint32_t, class Ordinal = Label, class Storage = Label*, bool weighted = true, class Weight = float, class WeightStorage = Weight*>
class pigo::Tensor

Holds coordinate-addressed tensors.

A Tensor is designed to read sparse tensor files and expose the resulting file as a coordinate list with weights.

tparam Label

the label data type. This type needs to be able to support the largest coordinate value read inside of the Tensor.

tparam Ordinal

the ordinal data type. This type needs to support large enough values to hold the number of entries or rows in the Tensor. It defaults to the same type as the label type.

tparam Storage

the storage type of the Tensor. This can either be vector (std::vector<Label>), a pointer (Label*), or a shared_ptr (std::shared_ptr<Label>).

tparam weighted

if true, support and use weights

tparam Weight

the weight data type.

tparam WeightStorage

the storage type for the weights. This can be a raw pointer (Weight*), a std::vector (std::vector<Weight>), or a std::shared_ptr<Weight>.

Public Functions

Tensor(std::string fn)

Initialize a Tensor from a file.

The file type will attempt to be determined automatically.

Parameters

fn – the filename to open

Tensor(std::string fn, FileType ft)

Initialize a Tensor from a file with a specific type.

Parameters

• fn – the filename to open

• ft – the FileType to use

Tensor(File &f, FileType ft)

Initialize a Tensor from an open File with a specific type.

Parameters

• f – the File to use

• ft – the FileType to use

inline Tensor()

Initialize an empty Tensor.

inline Tensor(Ordinal order, Ordinal m)

Provide space for copying in existing, out-of-band data.

inline Storage &c()

Retrieve the coordinate array.

Returns

the coordinate array in the format Storage

inline WeightStorage &w()

Retrieve the weight array.

Returns

the weight array in the format WeightStorage

inline Ordinal m() const

Retrieves the number of entries in the Tensor.

Returns

the count of entries

inline Ordinal order() const

Retrieves the order of the tensor.

Returns

the order of the tensor

void save(std::string fn)

Saves the Tensor to a binary PIGO file.

void write(std::string fn)

Write the Tensor out to an ASCII file.

inline void free()

Free consumed memory.

inline Tensor(const Tensor &other)

The copy constructor for creating a new Tensor.

inline Tensor &operator=(const Tensor &other)

The copy assignment operator.

Public Static Attributes

static constexpr const char *tensor_file_header = "PIGO-Tensor-v1"

The output file header for reading/writing