gauss.c

无线通信的各种运动模型。适用于移动通信、无线传感器网络等领域。 包括：Random walk、random waypoint、random direction、boundless simulation

/******************************************************************************
*   File Name: gauss.c
*   Purpose: gauss-markov mobility model.
*   Author: Jeff Boleng
*   Date Created:
*
*   Edited 12 July 2006 by Jon Petty:  
*   Changed seed code to rand((int)time(NULL) + (int)getpid())
*
*   Copyright (C) 2004  Toilers Research Group -- Colorado School of Mines
*
*   Please see COPYRIGHT.TXT and LICENSE.TXT for copyright and license
*   details.
******************************************************************************/ 

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <math.h>
#include <unistd.h>

#define true  1
#define false 0
#define min(a,b)  (((a) < (b)) ? (a) : (b))
#define max(a,b)  (((a) > (b)) ? (a) : (b))


int main(int argc, char *argv[])
{
	double pi = 2*asin(1.0);
	double alpha = 1.0;
	double meanSpeed = 10.0;
	double meanDirection = pi/2.0;

	double maxX=1000.0, maxY=1000.0;
	double endTime=1000.0;
	double interval = 1.0;

	double speed = meanSpeed;
	double direction = meanDirection;
	double xLoc = 0.0;
	double yLoc = 0.0;
	double curtime = 0.0;

	double randGauss()
	{
		double u = ((double)rand()/(double)RAND_MAX)*1.0;
		double v = ((double)rand()/(double)RAND_MAX)*1.0;
		double x;

		x = sqrt(-2*log(v))*cos(2*pi*u);

		return x;
	}

	double newSpeed(double oldV)
	{
		double v = 0.0;
		/*
		    double r = ((double)rand()/(double)RAND_MAX)*1.0;
		*/
		double r = randGauss();

		v = alpha*oldV + (1-alpha)*meanSpeed + sqrt(1-alpha*alpha) * r;
		return v;
	}

	double newDirection(double oldD, double x, double y)
	{
		double d = 0.0;

		double r = 0.0;
		double localDirection = meanDirection;

		if ((x<=100) && (y<=100))
		{
			localDirection = pi/4.0;
		} else if ((x<=100) && (y>=900)) {
			localDirection = 2.0*pi - pi/4.0;
		} else if ((x>=900) && (y>=900)) {
			localDirection = pi + pi/4.0;
		} else if ((x>=900) && (y<=100)) {
			localDirection = pi - pi/4.0;
		} else if (x<=100) {
			localDirection = 2.0*pi;
		} else if (x>=900) {
			localDirection = pi;
		} else if (y<=100) {
			localDirection = pi/2.0;
		} else if (y>=900) {
			localDirection = pi + pi/2.0;
		}
		/*
		    r = ((double)rand()/(double)RAND_MAX)*2.0*meanDirection;
		*/
		r = randGauss();

		d = alpha*oldD + (1-alpha)*localDirection + sqrt(1-alpha*alpha) * r;

		meanDirection = localDirection;

		return d;
	}


	if (argc == 2)
	{
		alpha            = atof(argv[1]);

		fprintf(stdout, "#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n");
		fprintf(stdout, "#\tmaxX               = %9.2f\n", maxX);
		fprintf(stdout, "#\tmaxY               = %9.2f\n", maxY);
		fprintf(stdout, "#\tendTime            = %9.2f\n", endTime);
		fprintf(stdout, "#\tmeanSpeed          = %9.2f\n", meanSpeed);
		fprintf(stdout, "#\talpha              = %9.2f\n", alpha);
		fprintf(stdout, "#\tinterval           = %9.2f\n", interval);
		fprintf(stdout, "#~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\n\n");
	} else {
		fprintf(stderr, "Usage:  gauss <alpha>\n");
		return -1;
	}

	/*
	*/
	srand((int)time(NULL) + (int)getpid());

	speed = meanSpeed;
	direction = meanDirection;
	xLoc = ((double)rand()/(double)RAND_MAX)*maxX;
	yLoc = ((double)rand()/(double)RAND_MAX)*maxY;
	xLoc = 500.0;
	yLoc = 500.0;

	fprintf(stdout, "set terminal postscript epsf solid\n");
	fprintf(stdout, "set output \"gauss%.2f.eps\"\n", alpha);
	fprintf(stdout, "set xrange[0:%f]\n", maxX);
	fprintf(stdout, "set yrange[0:%f]\n\n", maxY);
	fprintf(stdout, "set multiplot\n");
	fprintf(stdout, "plot \'-\' notitle with linespoints\n");
	fprintf(stdout, "%f  %f\ne\n", xLoc, yLoc);
	fprintf(stdout, "plot \'-\' notitle with lines\n");
	fprintf(stdout, "%f  %f\n", xLoc, yLoc);

	while (curtime <= endTime)
	{
		xLoc += speed*cos(direction);
		yLoc += speed*sin(direction);
		fprintf(stdout, "%f  %f\n", xLoc, yLoc);
		speed = newSpeed(speed);
		direction = newDirection(direction, xLoc, yLoc);
		curtime += interval;
	} /* while (curtime <= endTime) */

	fprintf(stdout, "e\n\n");
	fprintf(stdout, "plot \'-\' notitle with linespoints\n");
	fprintf(stdout, "%f  %f\ne\n", xLoc, yLoc);
	fprintf(stdout, "set nomultiplot\n");

	return 0;
}