cuda_2d_diffusion (ipynb)

2D Diffusion Simulation

This is a CUDA program that performs 2D diffusion on a grid of size NX x NY using the finite difference method. The program reads the initial grid values from a file and then performs a series of iterations to simulate the diffusion process.

Compiling the code

To compile the code, you will need to have a CUDA-compatible GPU and a CUDA compiler installed on your system. You can then use the nvcc compiler to compile the code by running the following command:

nvcc main.cu diffusion2d.cu etc.cu bmp.cu -o main

This will compile the main.cu and func.cu files and create an executable file named main.

Running the code

To run the code, you can use the following command:

./main

This will execute the main function, which initializes the grid and performs a series of iterations of the diffusion process. The program will output the current time and generate an image file at regular intervals. The program will continue until a certain number of iterations have been performed or until a maximum time has been reached.

Configuration

You can modify the behavior of the program by modifying the following constants:

• NX and NY: These constants define the size of the grid in the x and y dimensions, respectively.
• Lx and Ly: These constants define the size of the grid in physical units in the x and y dimensions, respectively.
• kappa: This constant represents the diffusion coefficient.
• nout: This constant determines how often the program outputs the current time and generates an image file.

You can also modify the initial grid values by modifying the initial function. This function is called at the beginning of the program and sets the initial values of the grid based on a given function.

Output

The program generates image files representing the state of the grid at regular intervals. The files are in BMP format and are named f000.bmp, f001.bmp, and so on. You can view these files using an image viewer or convert them to a different format using an image conversion tool.

The program also outputs the current time at regular intervals. The time is output to stderr and is expressed in units of the grid spacing squared divided by the diffusion coefficient.

Additional files

The program includes the following additional files:

• main.cu: This file is a mian file that simulates the diffusion of a 2D grid using the finite difference method.
• diffusion.cu: This file contains the implementation of the diffusion_2d function.
• etc.cu:This file contains several utility functions that are used by the main program.
• bmp.cu: This file contains the implementation of the generate_bmp_image function.

"The code in this project was developed based on the concepts and techniques described in the book 'はじめてのCUDAプログラミング' by 青木 尊之 (2009)."