chazhisuanfa.rar_c语言插值算法

#include "math.h" double eepqs(x0,h,n,y,t) int n; double x0,h,t,y[]; { int i,j,k,m,l; double z,hh,xi,xj,b[8]; z=0.0; if (n<1) return(z); if (n==1) { z=y[0]; return(z);} if (n<=8) { k=0; m=n;} else if (t<(x0+4.0*h)) { k=0; m=8;} else if (t>(x0+(n-5)*h)) { k=n-8; m=8;} else { k=(int)((t-x0)/h)-3; m=8;} b[0]=y[k]; for (i=2;i<=m;i++) { hh=y[i+k-1]; l=0; j=1; while ((l==0)&&(j<=i-1)) { if (fabs(hh-b[j-1])+1.0==1.0) l=1; else { xi=x0+(i+k-1)*h; xj=x0+(j+k-1)*h; hh=(xi-xj)/(hh-b[j-1]); } j=j+1; } b[i-1]=hh; if (l!=0) b[i-1]=1.0e+35; } z=b[m-1]; for (i=m-1;i>=1;i--) z=b[i-1]+(t-(x0+(i+k-1)*h))/z; return(z); }