解线性方程组的直接方法实验报告

解线性方程组的直接方法实验报告 解线性方程组的直接方法实验报告1.实验目的：1、通过该课题的实验，体会模块化结构程序设计方法的优点；2、运用所学的计算方法，解决各类线性方程组的直接算法；3、提高分析和解决问题的能力，做到学以致用；4、通过三对角形线性方程组的解法，体会稀疏线性方程组解法的特点。2.实验过程：实验代码：#include stdio.h#include math.h#includeusing namespace std;/gauss法void lzy(double *a,double *b,int n)int i,j,k;double l,x10,temp;for(k=0;kn-1;k+)for(j=k,i=k;jn;j+)if(j=k)temp=fabs(ajk);else if(tempfabs(ajk)temp=fabs(ajk);i=j;if(temp=0)cout无解 ;return;elsefor(j=k;jn;j+)temp=akj;akj=aij;aij=temp;temp=bk;bk=bi;bi=temp;for(i=k+1;in;i+)l=aik/akk;for(j=k;jn;j+)aij=aij-l*akj;bi=bi-l*bk;if(an-1n-1=0)cout无解 ;return;xn-1=bn-1/an-1n-1;for(i=n-2;i=0;i-)temp=0;for(j=i+1;jn;j+)temp=temp+aij*xj;xi=(bi-temp)/aii;for(i=0;in;i+)printf(x%d=%lf ,i+1,xi);printf( );/平方根法void pfg(double *a,double *b,int n)int i,k,m;double x8,y8,temp;for(k=0;kn;k+)temp=0;for(m=0;mk;m+)temp=temp+pow(akm,2);if(akktemp)return;akk=pow(akk-temp),1.0/2.0);for(i=k+1;in;i+)temp=0;for(m=0;mk;m+)temp=temp+aim*akm; aik=(aik-temp)/akk;temp=0;for(m=0;mk;m+)temp=temp+akm*ym;yk=(bk-temp)/akk;xn-1=yn-1/an-1n-1;for(k=n-2;k=0;k-)temp=0;for(m=k+1;mn;m+)temp=temp+amk*xm;xk=(yk-temp)/akk;for(i=0;in;i+)printf(x%d=%lf ,i+1,xi);printf( );/追赶法void zgf(double *a,double *b,int n)int i;double a010,c10,d10,a110,b110,x10,y10; for(i=0;in;i+)a0i=aii;if(in-1)ci=aii+1;if(i0)di-1=aii-1;a10=a00;for(i=0;in-1;i+)b1i=ci/a1i;a1i+1=a0i+1-di+1*b1i;y0=b0/a10;for(i=1;in;i+)yi=(bi-di*yi-1)/a1i;xn-1=yn-1;for(i=n-2;i=0;i-)xi=yi-b1i*xi+1;for(i=0;in;i+)printf(x%d=%lf ,i+1,xi);printf( );int mainint n,i,j;double *a,*b,*c,*b1,*b2,*b3;a=(double *)malloc(n*sizeof(double); b=(double *)malloc(n*sizeof(double);c=(double *)malloc(n*sizeof(double);b1=(double *)malloc(n*sizeof(double);b2=(double *)malloc(n*sizeof(double);b3=(double *)malloc(n*sizeof(double);for(i=0;in;i+)ai=(double *)malloc(n)*sizeof(double); bi=(double *)malloc(n)*sizeof(double); ci=(double *)malloc(n)*sizeof(double);