f2(y,x,yy);
printf("\n常微分方程组是y'=y-x and y(0)=2采用欧拉改进法求解得\n");
Байду номын сангаасf1(y,x,yy);
printf("\n常微分方程组是y'=x*x+2y and y(0)=1采用欧拉改进法求解得\n");
f1(y,x,yy);
}
}
};
void main()
{
double y[10],x[10],yy[10],y0[10];
printf("\n常微分方程组是y'=y-x and y(0)=2采用欧拉法求解得\n");
f1(y,x,yy);
printf("\n常微分方程组是y'=x*x+2y and y(0)=1采用欧拉法求解得\n");
}
};
void f4(double *y,double *x,double *yy,double *y0)
{
y[0]=1.0;
x[0]=0.0;
yy[0]=1.0;
for(int i=1;i<=9;i++)
{
x[i]=x[i-1]+0.2;
y0[i]=y[i-1]+0.2*(2*y[i-1]+x[i-1]*x[i-1]);
for(int i=1;i<=9;i++)
{
x[i]=x[i-1]+0.2;
y0[i]=y[i-1]+0.2*(y[i-1]-x[i-1]);
y[i]=y[i-1]+0.1*(y[i-1]-x[i-1]+y0[i-1]-x[i-1]);
yy[i]=x[i]+1+exp(x[i]);
printf("若x=%f,计算值是%f,真实值是%f,截断误差是%f\n ",x[i],y[i],yy[i],y[i]-yy[i]);
{
y[0]=1.0;
x[0]=0.0;
yy[0]=1.0;
for(int i=1;i<=9;i++)
{
x[i]=x[i-1]+0.2;
y[i]=y[i-1]+0.2*(2*y[i-1]+x[i-1]*x[i-1]);
yy[i]=-0.5*(x[i]*x[i]+x[i]+0.5)+1.25*exp(2*x[i]);
y[i]=y[i-1]+0.2*(y[i-1]-x[i-1]);
yy[i]=x[i]+1+exp(x[i]);
printf("若x=%f,计算值是%f,真实值是%f,截断误差是%f\n ",x[i],y[i],yy[i],y[i]-yy[i]);
}
};
void f2(double *y,double *x,double *yy)
printf("若x=%f,计算值是%f,真实值是%f,截断误差是%f\n ",x[i],y[i],yy[i],y[i]-yy[i]);
}
};
void f3(double *y,double *x,double *yy,double *y0)
{
y[0]=2.0;
x[0]=0.0;
yy[0]=2.0;
y[i]=y[i-1]+0.1*(2*y0[i-1]+x[i-1]*x[i-1]+2*y[i-1]+x[i-1]*x[i-1]);
yy[i]=-0.5*(x[i]*x[i]+x[i]+0.5)+1.25*exp(2*x[i]);
printf("若x=%f,计算值是%f,真实值是%f,截断误差是%f\n ",x[i],y[i],yy[i],y[i]-yy[i]);
生物信息技术0801徐聪U200812594
#include<stdio.h>
#include<math.h>
void f1(double *y,double *x,double *yy)
{
y[0]=2.0;
x[0]=0.0;
yy[0]=2.0;
for(int i=1;i<=9;i++)
{
x[i]=x[i-1]+0.2;