CUDA-Homework 4 CUDA Programming Solved

In this problem, you need to use CUDA to parallelize concurrent wave equation (http://en.wikipedia. org/wiki/Wave equation). Below show a serial implementation of the concurrent wave equation (http: //www.cs.nctu.edu.tw/∼ypyou/courses/PP-f19/assignments/HW4/serial wave.c).

/********************************************************************** * DESCRIPTION:

*            Serial Concurrent Wave Equation - C Version

*            This program implements the concurrent wave equation

*********************************************************************/

#include <stdio.h

#include <stdlib.h

#include <math.h

#include <time.h

#define MAXPOINTS 1000000

#define MAXSTEPS 1000000

#define MINPOINTS 20 #define PI 3.14159265

void check_param(void); void init_line(void); void update (void); void printfinal (void);

int nsteps,            /* number of time steps */ tpoints,  /* total points along string */ rcode; /* generic return code */

float values[MAXPOINTS+2],       /* values at time t */ oldval[MAXPOINTS+2],           /* values at time (t-dt) */ newval[MAXPOINTS+2]; /* values at time (t+dt) */

/********************************************************************** *               Checks input values from parameters

*********************************************************************/ void check_param(void)

{

char tchar[20];

/* check number of points, number of iterations */ while ((tpoints < MINPOINTS) || (tpoints MAXPOINTS)) { printf("Enter number of points along vibrating string [%d-%d]: "

,MINPOINTS, MAXPOINTS); scanf("%s", tchar); tpoints = atoi(tchar);

if ((tpoints < MINPOINTS) || (tpoints MAXPOINTS)) printf("Invalid. Please enter value between %d and %d\n", MINPOINTS, MAXPOINTS);

}

while ((nsteps < 1) || (nsteps MAXSTEPS)) { printf("Enter number of time steps [1-%d]: ", MAXSTEPS); scanf("%s", tchar);
nsteps = atoi(tchar); if ((nsteps < 1) || (nsteps MAXSTEPS)) printf("Invalid. Please enter value between 1 and %d\n", MAXSTEPS);

}

printf("Using points = %d, steps = %d\n", tpoints, nsteps);

}

/**********************************************************************

*                             Initialize points on line

*********************************************************************/ void init_line(void)

{

int i, j; float x, fac, k, tmp;

/* Calculate initial values based on sine curve */ fac = 2.0 * PI; k = 0.0; tmp = tpoints - 1; for (j = 1; j <= tpoints; j++) { x = k/tmp; values[j] = sin (fac * x); k = k + 1.0;

}

/* Initialize old values array */ for (i = 1; i <= tpoints; i++) oldval[i] = values[i];

}

/********************************************************************** *             Calculate new values using wave equation

*********************************************************************/ void do_math(int i)

{

float dtime, c, dx, tau, sqtau;

dtime = 0.3; c = 1.0; dx = 1.0; tau = (c * dtime / dx); sqtau = tau * tau;

newval[i] = (2.0 * values[i]) - oldval[i] + (sqtau * (-2.0)*values[ i]);

}

/********************************************************************** *             Update all values along line a specified number of times

*********************************************************************/ void update()

{

int i, j;

/* Update values for each time step */ for (i = 1; i<= nsteps; i++) {

/* Update points along line for this time step */ for (j = 1; j <= tpoints; j++) { /* global endpoints */ if ((j == 1) || (j == tpoints)) newval[j] = 0.0;

else do_math(j);

}

/* Update old values with new values */ for (j = 1; j <= tpoints; j++) { oldval[j] = values[j]; values[j] = newval[j];

}

}

}

/**********************************************************************

*                          Print final results

*********************************************************************/ void printfinal()

{

int i;

for (i = 1; i <= tpoints; i++) { printf("%6.4f ", values[i]); if (i%10 == 0)

printf("\n");

}

}

/**********************************************************************

*                      Main program

*********************************************************************/ int main(int argc, char *argv[])

{ sscanf(argv[1],"%d",&tpoints); sscanf(argv[2],"%d",&nsteps); check_param();

printf("Initializing points on the line...\n"); init_line();

printf("Updating all points for all time steps...\n"); update();

printf("Printing final results...\n"); printfinal(); printf("\nDone.\n\n");

return 0;

}
1         Requirements
•    Your program should take two command-line arguments, which indicate the number of points andthe number of iterations, respectively.

•    The output format should not be changed.

2         Development Environment
2.1        Building the CUDA environment on your own computer
If you have an nVIDIA GPU, you can build your own development environment by installing CUDA SDK.

https://developer.nvidia.com/cuda-downloads