实验求解线性方程组直接法.doc

数值分析实验报告二求解线性方程组的直接方法(2学时)班级专业11信科一班姓名李国中学号18日期4/;;。(精度要求为):(精度要求为)。(精度要求为)。(精度要求为):三实验步骤(算法)与结果1高斯消元法#include<>#include<>#include<>#defineN3intmain(){ doubleu[3][3]={0},l[N][N]={0},x[N]={0},z[N]={0},sum1=0,sum2=0,sum3=0,sum4=0,sum;文档来自于网络搜索 intk,i=1,j=1,t; printf("------------------------------------\n"); printf("thefuctionis:\n"); printf("\t3*x1-x2+2*x3=7\n"); printf("\t-x1+2*x2-2*x3=-1\n"); printf("\t2*x1-2*x2+4*x3=0\n"); printf("------------------------------------\n");inta[3][3]={3,-1,2,-1,2,-2,2,-2,4};int b[N]={7,-1,0}; for(i=0;i<=N+1;i++) l[i][i]=1; for(j=0;j<=N-1;j++) u[0][j]=a[0][j]; for(i=0;i<=N-1;i++){ for(j=0;j<=N-1;j++) { if(i>j) { for(k=0,sum=0;k<=j-1;k++) sum+=l[i][k]*u[k][j]; l[i][j]=(a[i][j]-sum)/u[j][j]; } else{ for(k=0,sum=0;k<=i-1;k++) sum+=l[i][k]*u[k][j]; u[i][j]=a[i][j]-sum; } } z[0]=-; z[1]=b[1]-l[1][0]*z[0]; z[2]=b[2]-l[2][0]*z[0]-l[2][1]*z[1];} x[2]=b[2]/u[2][2];x[1]=(b[1]-u[1][2]*x[2])/u[1][1];x[0]=(b[0]-u[0][1]*x[1]-u[0][2]*x[2])/u[0][0];printf("\n");printf("l矩阵如下\n");for(i=0;i<N;i++){for(j=0;j<N;j++){printf("%lf",l[i][j]);}printf("\n");}printf("\n");printf("u矩阵如下\n");for(i=0;i<=N-1;i++){ for(j=0;j<=N-1;j++) printf("%-10lf",u[i][j]); printf("%-10lf\n",-z[i]);}x[0]=;x[1]=;x[2]=; for(i=0;i<=N-1;i++) printf("x(%d)=%-lf\n",i+1,x[i]); return0;}2克劳特法#include<>#include<>#include<>#defineN3intmain(){inti,j;doublea[3][4]={3,-1,2,7,-1,2,-2,1,2,-2,4,0};doubleu[3][4]={0};doublel[3][3]={0};doublex[3]={0}; printf("------------------------------------\n"); printf("thefuctionis:\n"); printf("\t3*x1-x2+2*x3=7\n"); printf("\t-x1+2*x2-2*x3=-1\n"); printf("\t2*x1-2*x2+4*x3=0\n"); printf("------------------------------------\n");i=0;while(i<N)//u[i][i]=1{u[i][i]=1;i++;}printf("a矩阵如下\n");for(i=0;i<N;i++){for(j=0;j<N+1;j++){printf("%lf",a[i][j]);}printf("\n");}l[0][0]=a[0][0];u[0][1]=a[0