信号分析课程的各种程序，信号频谱分析，DDT，DFT，滤波器，假频，频谱泄露

#define pi 3.1415926 #include <math.h> #include <stdio.h> #define M 41 #define N 301 #define L 341 void conv1(x,m,h,n,y,l) float x[],h[],y[]; int m,n,l; { int k,i; for(k=0;k<l;k++) { y[k]=0.0; for(i=0;i<m;i++) if(k-i>=0&&k-i<=n-1)y[k]=y[k]+x[i]*h[k-i]; } } main() { int i; float t,q,fm=35.0,dt; float x[M],h[N],y[L]; FILE *fp1,*fp2; //Generate a Ricker wavelet fp1=fopen("Ricker.xls","w"); fp2=fopen("yt.xls","w"); printf("Please input dt(s):\n"); scanf("%f",&dt); for(i=-M/2;i<=M/2;i++) { t=i*dt; q=pi*fm*t; x[i+M/2]=(1-2*q*q)*exp(-q*q); fprintf(fp1,"%4d \t %7.4f \t %10.4f\n",i,t,x[i+M/2]); } fclose(fp1); for(i=0;i<N;i++) h[i]=0.0; h[50]=1.0; h[100]=0.5; h[200]=-1.0; conv1(x,M,h,N,y,L); for(i=(M-1)/2;i<L-(M-1)/2;i++) { t=i*dt; fprintf(fp2,"%4d \t %7.4f \t %10.4f\n",i,t,y[i]); } fclose(fp2); }