Friends,
i have written a program in FOTRAN for solving a equation [f(x0,y0)= 2*(y**2)+5]
I'm in the learning stage of FOTRAN. So please don't mind if my program has got any silly mistakes.
Please help in executing the program.
program rungekutta
print *,' DIFFERENTIAL EQUATION WITH 1 VARIABLE OF ORDER 1'
print*,"enter the value of x0"
read*,x
print*,"enter the value of y0"
read*,y
print*,"enter the value of step size"
read*,h
print*,"solution for the equation is",rk(x0,y0,h)
call runge(m,f1,n,h,x1)
end
function rk(y) result(r)
!Example: y'=(2*y^2+5)
real y,r
r = (2*(y**2)+5)
end function rk(y)
Subroutine runge(m,f1,n,h,x1)
integer f1,i,j,m,n,h
real x,w1,w2,w3,w4,x0,y;
do i=1, m
ni = (i  1) * f1  1
do j=1, f1
x = x1 + h * (n + j)
w1 = h * f(x0,y0)
w2 = h * f(x0+h/2, y0+w1/2)
w3 = h * f(x0+h/2, y0+w2/2)
w4 = h * f(x0+h, y0+w3)
x = x0 + h
x = y + (w1 + w2 + w2 + w3 + w3 + w4) / 6
end do
end do
end
