ndarray Documentation

Summary

ndarray is a C++ template library for n-dimensional arrays on CPU and GPU using NVIDIA CUDA™. It is extracted from the CUV library.

Features

Supported Platforms

• This library was only tested on Ubuntu Karmic, Lucid and Maverick. It uses mostly standard components and should run without major modification on any current linux system.

Supported GPUs

• By default, code is generated for the lowest compute architecture. We recommend you change this to match your hardware. Using ccmake you can set the build variable "CUDA_ARCHITECTURE" for example to -arch=compute_20
• All GT 9800 and GTX 280 and above
• GT 9200 without convolutions. It might need some minor modifications to make the rest work. If you want to use that card and have problems, just get in contact.
• On 8800GTS, random numbers and convolutions wont work.

Installation

Dependencies

To build the C++ lib, you will need:

• cmake (and cmake-curses-gui for easy configuration)
• libboost-dev >= 1.37
• NVIDIA CUDA (tm), including SDK. We support versions 3.X, 4.X and 5.X
• thrust library - included in CUDA since 4.0

Building a debug version

mkdir -p build/debug
cd build/debug
cmake -DCMAKE_BUILD_TYPE=Release ../../
ccmake .             # adjust paths to your system (cuda, thrust, ...)!
make -j
ctest                # run tests to see if it went well
sudo make install

Building a release version

mkdir -p build/release
cd build/release
cmake -DCMAKE_BUILD_TYPE=Release ../../
ccmake .             # adjust paths to your system (cuda, thrust, ...)!
make -j
ctest                # run tests to see if it went well
sudo make install

Usage

Example

#include <cuv/ndarray.hpp>

int main(void) {

	// allocate a 10×20 array of ints in row-major order on host (CPU)
	cuv::ndarray<int, cuv::host_memory_space> a_host(10, 20);

	assert(a_host.ndim() == 2);        // a_host is a two-dimensional array
	assert(a_host.size() == 10 * 20);

	// initialize the array
	int x = 0;
	for(int i=0; i < a_host.shape(0); i++) { // shape(0) == 10
		for(int j=0; j < a_host.shape(1); j++) { // shape(1) == 20
			a_host(i, j) = x++;
		}
	}

	// reshape to a 20×10 array
	a_host.reshape(20, 10);
	assert(a_host.shape(0) == 20);
	assert(a_host.shape(1) == 10);

	// copy the array to the GPU
	cuv::ndarray<int, cuv::dev_memory_space> a_device = a_host;

	// get the pointer to global device memory
	int* device_ptr = a_device.ptr();

	return 0;
}