TinyNdArray

Single Header C++ Implementation of NumPy NdArray.

I look forward to your pull-request.

Requirement

C++14 compiler

Sample Code

#define TINYNDARRAY_IMPLEMENTATION
#include "tinyndarray.h"

using tinyndarray::NdArray;

int main(int argc, char const* argv[]) {
    auto m1 = NdArray::Arange(12).reshape(2, 2, 3) - 2.f;
    auto m2 = NdArray::Ones(3, 1) * 10.f;
    auto m12 = m1.dot(m2);
    std::cout << m12 << std::endl;

    NdArray m3 = {{{-0.4f, 0.3f}, {-0.2f, 0.1f}},
                  {{-0.1f, 0.2f}, {-0.3f, 0.4f}}};
    m3 = Sin(std::move(m3));
    std::cout << m3 << std::endl;

    auto sum_abs = Abs(m3).sum();
    std::cout << sum_abs << std::endl;

    auto m4 = Where(0.f < m3, -100.f, 100.f);
    bool all_m4 = All(m4);
    bool any_m4 = Any(m4);
    std::cout << m4 << std::endl;
    std::cout << all_m4 << " " << any_m4 << std::endl;

    return 0;
}

Quick Guide

TinyNdArray supports only float array.

In the following Python code dtype=float32 is omitted, and in C++ code assuming using namespace tinyndarray; is declared.

For more detail, please see declarations in top of the header file.

Copy behavior

Copy behavior of NdArray is shallow copy which is same as NumPy.

Numpy (Python)	TinyNdArray (C++)
a = np.ones((2, 3)) b = a b[0, 0] = -1 print(a[0, 0]) # -1	auto a = NdArray::Ones(2, 3); auto b = a; b[{0, 0}] = -1; std::cout << a[{0, 0}] << std::endl; // -1

Basic Constructing

Numpy (Python)	TinyNdArray (C++)
`a = np.array([2, 3])`	`NdArray a({2, 3});` or
	`NdArray a(Shape{2, 3});`

Float Initializer

Supports up to 10 dimensions.

Numpy (Python)	TinyNdArray (C++)
`a = np.array([1.0, 2.0])`	`NdArray a = {1.f, 2.f};`
`a = np.array([[1.0, 2.0]])`	`NdArray a = {{1.f, 2.f}};`
`a = np.array([[1.0, 2.0], [3.0, 4.0]])`	`NdArray a = {{1.f, 2.f}, {3.f, 4.f}};`
`a = np.array([[[[[[[[[[1.0, 2.0]]]]]]]]]])`	`NdArray a = {{{{{{{{{{1.f, 2.f}}}}}}}}}};`

Static Initializer

Numpy (Python)	TinyNdArray (C++)
`a = np.empty((2, 3))`	`auto a = NdArray::Empty(2, 3);` or
	`auto a = NdArray::Empty({2, 3});` or
	`auto a = NdArray::Empty(Shape{2, 3});`
`a = np.zeros((2, 3))`	`auto a = NdArray::Zeros(2, 3);` or
	`auto a = NdArray::Zeros({2, 3});` or
	`auto a = NdArray::Zeros(Shape{2, 3});`
`a = np.ones((2, 3))`	`auto a = NdArray::Ones(2, 3);` or
	`auto a = NdArray::Ones({2, 3});` or
	`auto a = NdArray::Ones(Shape{2, 3});`
`a = np.arange(10)`	`auto a = NdArray::Arange(10);`
`a = np.arange(0, 100, 10)`	`auto a = NdArray::Arange(0, 100, 10);`

Random Initializer

Numpy (Python)	TinyNdArray (C++)
`a = np.random.uniform(10)`	`auto a = NdArray::Uniform(10);`
`a = np.random.uniform(size=(2, 10))`	`auto a = NdArray::Uniform({2, 10});` or
	`auto a = NdArray::Uniform(Shape{2, 10});`
`a = np.random.uniform(low=0.0, high=1.0, size=10)`	`auto a = NdArray::Uniform(0.0, 1.0, {10});` or
	`auto a = NdArray::Uniform(0.0, 1.0, Shape{10});`
`a = np.random.normal(10)`	`auto a = NdArray::Normal(10);`
`a = np.random.normal(size=(2, 10))`	`auto a = NdArray::Normal({2, 10});` or
	`auto a = NdArray::Normal(Shape{2, 10});`
`a = np.random.normal(loc=0.0, scale=1.0, size=10)`	`auto a = NdArray::Normal(0.0, 1.0, {10});` or
	`auto a = NdArray::Normal(0.0, 1.0, Shape{10});`

Random Seed

Numpy (Python)	TinyNdArray (C++)
`a = np.random.seed()`	`auto a = NdArray::Seed();`
`a = np.random.seed(0)`	`auto a = NdArray::Seed(0);`

Basic Embeded Method

Numpy (Python)	TinyNdArray (C++)
`id(a)`	`a.id()`
`a.size`	`a.size()`
`a.shape`	`a.shape()`
`a.ndim`	`a.ndim()`
`a.fill(2.0)`	`a.fill(2.f)`
`a.copy()`	`a.copy()`

Original Embeded Method

Numpy (Python)	TinyNdArray (C++)
`---`	`a.empty()`
`---`	`a.data()`
`---`	`a.begin()`
`---`	`a.end()`

Single Element Casting

Numpy (Python)	TinyNdArray (C++)
`float(a)`	`static_cast<float>(a)`

Index Access

Numpy (Python)	TinyNdArray (C++)
`a[2, -3]`	`a[{2, -3}]` or
	`a[Index{2, -3}]` or
	`a(2, -3)`

Reshape methods

Numpy (Python)	TinyNdArray (C++)
`a.reshape(-1, 2, 1)`	`a.reshape({-1, 2, 1})` or
	`a.reshape(Shape{-1, 2, 1})` or
	`a.reshape(-1, 2, 1)`
`a.flatten()`	`a.flatten()`
`a.ravel()`	`a.ravel()`

Reshape functions

Numpy (Python)	TinyNdArray (C++)
`np.reshape(a, (-1, 2, 1))`	`Reshape(a, {-1, 2, 1})`
`np.squeeze(a)`	`Squeeze(a)`
`np.squeeze(a, [0, -2])`	`Squeeze(a, {0, -2})`
`np.expand_dims(a, 1)`	`ExpandDims(a, 1)`

Slice

Slice methods create copy of the array, not reference.

Numpy (Python)	TinyNdArray (C++)
`a[1:5, -4:-1]`	`a.slice({{1, 5}, {-4, -1}})` or
	`a.slice(SliceIndex{{1, 5}, {-4, -1}})` or
	`a.slice({1, 5}, {-4, -1})`

Print

Numpy (Python)	TinyNdArray (C++)
`print(a)`	`std::cout << a << std::endl;`

Single Operators

Numpy (Python)	TinyNdArray (C++)
`+np.ones((2, 3))`	`+NdArray::Ones(2, 3)`
`-np.ones((2, 3))`	`-NdArray::Ones(2, 3)`

Arithmetic Operators

All operaters supports broadcast.

Numpy (Python)	TinyNdArray (C++)
`np.ones((2, 1, 3)) + np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) + NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) - np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) - NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) * np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) * NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) / np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) / NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) + 2.0`	`NdArray::Ones(2, 1, 3) + 2.f`
`np.ones((2, 1, 3)) - 2.0`	`NdArray::Ones(2, 1, 3) - 2.f`
`np.ones((2, 1, 3)) * 2.0`	`NdArray::Ones(2, 1, 3) * 2.f`
`np.ones((2, 1, 3)) / 2.0`	`NdArray::Ones(2, 1, 3) / 2.f`
`2.0 + np.ones((2, 1, 3))`	`2.f + NdArray::Ones(2, 1, 3)`
`2.0 - np.ones((2, 1, 3))`	`2.f - NdArray::Ones(2, 1, 3)`
`2.0 * np.ones((2, 1, 3))`	`2.f * NdArray::Ones(2, 1, 3)`
`2.0 / np.ones((2, 1, 3))`	`2.f / NdArray::Ones(2, 1, 3)`

Comparison Operators

All operaters supports broadcast.

Numpy (Python)	TinyNdArray (C++)
`np.ones((2, 1, 3)) == np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) == NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) != np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) != NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) > np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) > NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) >= np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) >= NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) < np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) < NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) <= np.ones((4, 1))`	`NdArray::Ones(2, 1, 3) <= NdArray::Ones(4, 1)`
`np.ones((2, 1, 3)) == 1.f`	`NdArray::Ones(2, 1, 3) == 1.f`
`np.ones((2, 1, 3)) != 1.f`	`NdArray::Ones(2, 1, 3) != 1.f`
`np.ones((2, 1, 3)) > 1.f`	`NdArray::Ones(2, 1, 3) > 1.f`
`np.ones((2, 1, 3)) >= 1.f`	`NdArray::Ones(2, 1, 3) >= 1.f`
`np.ones((2, 1, 3)) < 1.f`	`NdArray::Ones(2, 1, 3) < 1.f`
`np.ones((2, 1, 3)) <= 1.f`	`NdArray::Ones(2, 1, 3) <= 1.f`
`1.f == np.ones((4, 1))`	`1.f == NdArray::Ones(4, 1)`
`1.f != np.ones((4, 1))`	`1.f != NdArray::Ones(4, 1)`
`1.f > np.ones((4, 1))`	`1.f > NdArray::Ones(4, 1)`
`1.f >= np.ones(4, 1))`	`1.f >= NdArray::Ones(4, 1)`
`1.f < np.ones((4, 1))`	`1.f < NdArray::Ones(4, 1)`
`1.f <= np.ones((4, 1))`	`1.f <= NdArray::Ones(4, 1)`

Compound Assignment Operators

All operaters supports broadcast. However, left-side variable keep its size.

Numpy (Python)	TinyNdArray (C++)
`np.ones((2, 1, 3)) += np.ones(3)`	`NdArray::Ones(2, 1, 3) += NdArray::Ones(3)`
`np.ones((2, 1, 3)) -= np.ones(3)`	`NdArray::Ones(2, 1, 3) -= NdArray::Ones(3)`
`np.ones((2, 1, 3)) *= np.ones(3)`	`NdArray::Ones(2, 1, 3) *= NdArray::Ones(3)`
`np.ones((2, 1, 3)) /= np.ones(3)`	`NdArray::Ones(2, 1, 3) /= NdArray::Ones(3)`
`np.ones((2, 1, 3)) += 2.f`	`NdArray::Ones(2, 1, 3) += 2.f`
`np.ones((2, 1, 3)) -= 2.f`	`NdArray::Ones(2, 1, 3) -= 2.f`
`np.ones((2, 1, 3)) *= 2.f`	`NdArray::Ones(2, 1, 3) *= 2.f`
`np.ones((2, 1, 3)) /= 2.f`	`NdArray::Ones(2, 1, 3) /= 2.f`

Math Functions

Functions which takes two arguments support broadcast.

Numpy (Python)	TinyNdArray (C++)
`np.abs(a)`	`Abs(a)`
`np.sign(a)`	`Sign(a)`
`np.ceil(a)`	`Ceil(a)`
`np.floor(a)`	`Floor(a)`
`np.clip(a, x_min, x_max)`	`Clip(a, x_min, x_max)`
`np.sqrt(a)`	`Sqrt(a)`
`np.exp(a)`	`Exp(a)`
`np.log(a)`	`Log(a)`
`np.square(a)`	`Square(a)`
`np.power(a, b)`	`Power(a, b)`
`np.power(a, 2.0)`	`Power(a, 2.f)`
`np.power(2.0, a)`	`Power(2.f, a)`
`np.sin(a)`	`Sin(a)`
`np.cos(a)`	`Cos(a)`
`np.tan(a)`	`Tan(a)`
`np.arcsin(a)`	`ArcSin(a)`
`np.arccos(a)`	`ArcCos(a)`
`np.arctan(a)`	`ArcTan(a)`
`np.arctan2(a, b)`	`ArcTan2(a, b)`
`np.arctan2(a, 10.0)`	`ArcTan2(a, 10.f)`
`np.arctan2(10.0, a)`	`ArcTan2(10.f, a)`

Axis Functions

Numpy (Python)	TinyNdArray (C++)
`np.sum(a)`	`Sum(a)`
`np.sum(a, axis=0)`	`Sum(a, {0})` or
	`Sum(a, Axis{0})`
`np.sum(a, axis=(0, 2))`	`Sum(a, {0, 2})` or
	`Sum(a, Axis{0, 2})`
`np.mean(a, axis=0)`	`Mean(a, {0})`
`np.min(a, axis=0)`	`Min(a, {0})`
`np.max(a, axis=0)`	`Max(a, {0})`

Logistic Functions

Numpy (Python)	TinyNdArray (C++)
`np.all(a)`	`All(a, {0})`
`np.all(a, axis=0)`	`All(a, {0})`
`np.any(a)`	`Any(a, {0})`
`np.any(a, axis=0)`	`Any(a, {0})`
`np.where(condition, x, y)`	`Where(condition, x, y)`

Axis Method

Numpy (Python)	TinyNdArray (C++)
`a.sum()`	`a.sum()`
`a.sum(axis=0)`	`a.sum({0})` or
	`a.sum(Axis{0})`
`a.sum(axis=(0, 2))`	`a.sum({0, 2})` or
	`a.sum(Axis{0, 2})`
`a.mean(axis=0)`	`a.mean({0})`
`a.min(axis=0)`	`a.min({0})`
`a.max(axis=0)`	`a.max({0})`

Grouping Functions

Numpy (Python)	TinyNdArray (C++)
`np.stack((a, b, ...), axis=0)`	`Stack({a, b, ...}, 0)`
`np.concatenate((a, b, ...), axis=0)`	`Concatenate({a, b, ...}, 0)`
`np.split(a, 2, axis=0)`	`Split(a, 2, 0)`
`np.split(a, [1, 3], axis=0)`	`Split(a, {1, 3}, 0)`
	`Separate(a, 0)` An inverse of Stack(a, 0)

View Changing Functions

View chaining methods create copy of the array, not reference.

Numpy (Python)	TinyNdArray (C++)
`np.transpose(x)`	`Transpose(x)`
`np.swapaxes(x, 0, 2)`	`Swapaxes(x, 0, 2)`
`np.broadcast_to(x, (3, 2))`	`BroadcastTo(x, {3, 2})`
	`SumTo(x, {3, 2})` An inverse of BroadcastTo(x, {3, 2})

Matrix Products

All dimension rules of numpy are implemented.

Numpy (Python)	TinyNdArray (C++)
`np.dot(a, b)`	`Dot(a, b)`
`a.dot(b)`	`a.dot(b)`
`np.matmul(a, b)`	`Matmul(a, b)`
`np.cross(a, b)`	`Cross(a, b)`
`a.cross(b)`	`a.cross(b)`

Inverse

All dimension rules of numpy are implemented.

Numpy (Python)	TinyNdArray (C++)
`np.linalg.inv(a)`	`Inv(a, b)`

In-place Operation

In NumPy, in-place and not inplace operations are written by following.

Numpy (Python) In-place	Numpy (Python) Not in-place
a = np.ones((2, 3)) a_id = id(a) np.exp(a, out=a) # in-place print(id(a) == a_id) # True	a = np.ones((2, 3)) a_id = id(a) a = np.exp(a) # not in-place print(id(a) == a_id) # False

In TinyNdArray, when right-reference values are passed, no new arrays are created and operated in-place.

TinyNdArray (C++) In-place

TinyNdArray (C++) Not in-place

    auto a = NdArray::Ones(2, 3);
    auto a_id = a.id();
    a = np.exp(std::move(a));  // in-place
    std::cout << (a.id() == a_id)
              << std::endl;  // true

    auto a = NdArray::Ones(2, 3);
    auto a_id = a.id();
    a = np.exp(a);  // not in-place
    std::cout << (a.id() == a_id)
              << std::endl;  // false

However, even right-reference values are passed, when the size is changed by broadcasting, a new array will be created.

TinyNdArray (C++) In-place

TinyNdArray (C++) Not in-place

   auto a = NdArray::Ones(2, 1, 3);
   auto b = NdArray::Ones(3);
   auto a_id = a.id();
   a = np.exp(std::move(a));  // in-place
   std::cout << a.shape()
             << std::endl;  // [2, 1, 3]
   std::cout << (a.id() == a_id)
             << std::endl;  // true

   auto a = NdArray::Ones(2, 1, 3);
   auto a = NdArray::Ones(3, 1);
   auto a_id = a.id();
   a = np.exp(srd::move(a));  // looks like in-place
   std::cout << a.shape()
             << std::endl;  // [2, 3, 3]
   std::cout << (a.id() == a_id)
             << std::endl;  // false

Parallel Execusion

In default, most of all operations run in parallel by threads.

When changing the number of workers, please set via NdArray::SetNumWorkers().

// Default setting. Use all of cores.
NdArray::SetNumWorkers(-1);
// Set no parallel.
NdArray::SetNumWorkers(1);
// Use 4 cores
NdArray::SetNumWorkers(4);

Memory profiling

When a macro TINYNDARRAY_PROFILE_MEMORY is defined, memory profiler is activated.

The following methods can be used to get the number of instances and the size of allocated memories..

NdArray::GetNumInstance() NdArray::GetTotalMemory()

Macros

TINYNDARRAY_H_ONCE
TINYNDARRAY_NO_INCLUDE
TINYNDARRAY_NO_NAMESPACE
TINYNDARRAY_NO_DECLARATION
TINYNDARRAY_IMPLEMENTATION
TINYNDARRAY_PROFILE_MEMORY

TODO

Replace axis reduction function with more effective algorithm.
- Implement more effective algorithm.
Replace slice method's recursive call with loop for speed up.
- Make parallel
Improve inverse function with LU decomposition.
Implement reference slice which dose not effect the current performance.
Introduce SIMD instructions.

Everything in the upper list are difficult challenges. If you have any ideas, please let me know.

Name		Name	Last commit message	Last commit date
Latest commit History 120 Commits
tests		tests
.clang-format		.clang-format
.gitignore		.gitignore
.gitmodules		.gitmodules
LICENSE		LICENSE
README.md		README.md
tinyndarray.h		tinyndarray.h

License

viix-co/tinyndarray

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