mmm.java

自己编写的

package fft;

/**
 * 此处插入类型描述。
 * 创建日期：(2003-10-9 19:15:50)
 * @author：Administrator
 */
import java.io.*;
import java.awt.Graphics;
import java.awt.*;
import java.applet.Applet;

public class Mmm extends Applet {

    public static DoFFT usefft;
    public static String s;
    public static double output[];
    public static int N = 64;

    private static double test[];//2003.12.9

    public static double testArray[][];

    Dimension d; //定义画布尺寸

    //在此处用来启动应用程序的代码。
    public void start() {

        // 直接读二进制文件，输出幅值

       s = new String("1070854414896");
       // s = new String("fft");
        output = new double[N];

        usefft = new DoFFT(s);

        
        test = new double[N];
        for(int i=0;i<N;i++){
	      test[i]=Math.exp(-0.1*i);  
	    }
        
        //output = usefft.fft_sy(test);//2003.12.9 付立叶变换
        
       // output = usefft.fft_sy(usefft.input);//付立叶变换
        output = usefft.powerspetrum(usefft.input);//功率谱分析
       // output = usefft.cepstrum(usefft.input);//倒频谱分析

         for (int i = 0; i < N; i++) {
             // output[i]=20*Math.log(Math.abs(output[i]))/Math.log(10);
             //线性幅值与对数幅值
	         
              // System.out.println(i + "  " + (float)output[i]);

          }

        //return output;
    } //end of method

    public void paint(Graphics g) {

        float xcur = 0, xprev = 0, ycur = 0, yprev = (float)output[0], ymax = 0;
       // d = size();

        for (int i = 0; i < N; i++) {
	        ycur = (float) output[i];
	        
            if (ycur > ymax) {
                ymax = ycur;
            }
        }
        
        //System.out.println( " \n  Ymax  =  " + ymax);
            yprev=200-200*yprev/ymax;
            g.setColor(Color.black); 
        
        for (int i = 0; i < N/2; i ++) {

            ycur = (float) output[i];
            ycur=200-200*ycur/ymax;

            g.drawLine(Math.round(xprev),Math.round(yprev),Math.round(xcur),Math.round(ycur));

            xcur += 1;
            xprev = xcur;
            yprev = ycur;
        }

    }
}