编辑代码

PROGRAM T2
        IMPLICIT NONE
        REAL,PARAMETER::h=0.1
        REAL(8) F
        REAL(8)::k1,k2,k3,k4,X=0.0,Y=1.0
        INTEGER I
        OPEN(1,FILE='DATA1.TXT')
    
        DO I=1,10
           k1=h*F(X,Y)
           k2=h*F(X+h/2.0,Y+k1/2.0)
           k3=h*F(X+h/2.0,Y+k2/2.0)
           k4=h*F(X+h,Y+k3)
           Y=Y+(k1+2*k2+2*k3+k4)/6.0
           
           X=X+h
           PRINT*,"X=",X, "Y=",Y
           WRITE(1,10),X,Y
 10      FORMAT(F10.6,2X,F10.6)
        END DO 
    
    END  
    
        FUNCTION F(X,Y)
          REAL(8) F
          REAL(8) ::X,Y
          F=Y
        END FUNCTION