[子程序] 求改正，输出多个子程序返回值的问题

program main
implicit none
call sub2()
end program main

subroutine sub1(X,Y,T,a,b,c,d,ans)
implicit none
real::PI=3.1415926
real::PM=1
real::M=1
real::PL=1
real::PT=1
real,parameter::X0=20
real,parameter::Y0=20
real,parameter::T0=20
real::a(X0,Y0,T0)
real::b(X0,Y0,T0)
real::c(X0,Y0,T0)
real::d(X0,Y0,T0)
real::ans(X0,Y0,T0)
real X
real Y
real T 
real::x1,x2,dx,y1,y2,dy,t1,t2,dt
integer::i,j,k,Nx,Ny,Nt
x1=0.5
x2=10
y1=0.5
y2=10
t1=0.5
t2=10
dx=0.5
dy=0.5
dt=0.5
Nx=(x2-x1)/dx
Ny=(y2-y1)/dy
Nt=(t2-t1)/dt
open(unit=10,file="data1.txt")
do i=1,Nx+1
  X=x1+(i-1)*dx
    do j=1,Ny+1
          y=y1+(j-1)*dy
      do k=1,Nt+1 
      T=t1+(k-1)*dt
      a(i,j,k)=PM*M/(4*(PI**1)*(PL**0.5)*(PT**0.5)*(T**1))
      b(i,j,k)=-1/(2*PL*T)
      c(i,j,k)=((X-T)/(2*PL*T))**2
      d(i,j,k)=((X-T)**2)/(4*PL*T)+(y**2/(4*PT*T))
      ans(i,j,k)=(PM*M/(4*(PI**1)*(PL**0.5)*(PT**0.5)*(T**2)))*((-1/(2*PL*T))+((((X-T)/(2*PL*T))**2)**2))*(exp(-(((X-T)**2)/(4*PL*T)+(y**2/(4*PT*T)))))
      write(10,"('(',f5.2,',',f5.2,','f5.2')=',(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6))") X,Y,T,a(i,j,k),b(i,j,k),c(i,j,k),d(i,j,k),ans(i,j,k)
      end do
  end do
end do
return
end

subroutine sub2()
implicit none
integer,parameter:: i=20
integer,parameter:: j=20
integer,parameter:: k=20
real X
real Y
real T
real::a(i,j,k)
real::b(i,j,k)
real::c(i,j,k)
real::d(i,j,k)
real::ans(i,j,k)
    call sub1(X,Y,T,a,b,c,d,ans)
    open(unit=11,file='data2.txt')
    if (ans(i,j,k)>-0.01.and.ans(i,j,k)<0.01) then
    write(11,"('(',f5.2,',',f5.2,','f5.2')=',(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6))") X,Y,T,a(i,j,k),b(i,j,k),c(i,j,k),d(i,j,k),ans(i,j,k)
    end if
return 
end

do i = 1 , ...
  do j = 1 , ...
    do k = 1 , ...
      if (ans(i,j,k)>-0.01.and.ans(i,j,k)<0.01) then
       write(11,"('(',f5.2,',',f5.2,','f5.2')=',(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6))") X,Y,T,a(i,j,k),b(i,j,k),c(i,j,k),d(i,j,k),ans(i,j,k)
      end if
    end do
  end do
end do

subroutine sub2()
implicit none
integer,parameter:: i0=20
integer,parameter:: j0=20
integer,parameter:: k0=20
integer i
integer j
integer k
real X
real Y
real T
real::a(i,j,k)
real::b(i,j,k)
real::c(i,j,k)
real::d(i,j,k)
real::ans(i,j,k)
    call sub1(X,Y,T,a,b,c,d,ans)
    open(unit=11,file='data2.txt')
        do i1=1,i0
          do j1=1,j0
            do k1=1,k0
    if (ans(i,j,k)>-0.01.and.ans(i,j,k)<0.01) then
    write(11,"('(',f5.2,',',f5.2,','f5.2')=',(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6))") X,Y,T,a(i,j,k),b(i,j,k),c(i,j,k),d(i,j,k),ans(i,j,k)
    end if
        end do
  end do
end do
return 
end

subroutine sub2()
 implicit none
 integer,parameter:: i0=20
 integer,parameter:: j0=20
 integer,parameter:: k0=20
 integer i
 integer j
 integer k
 real X
 real Y
 real T
 real::a(i0,j0,k0)
 real::b(i0,j0,k0)
 real::c(i0,j0,k0)
 real::d(i0,j0,k0)
 real::ans(i0,j0,k0)
     call sub1(X,Y,T,a,b,c,d,ans)
     open(unit=11,file='data2.txt')
         do i=1,i0
           do j=1,j0
             do k=1,k0
     if (ans(i,j,k)>-0.01.and.ans(i,j,k)<0.01) then
     write(11,"('(',f5.2,',',f5.2,','f5.2')=',(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6),(2X,F9.6))") X,Y,T,a(i,j,k),b(i,j,k),c(i,j,k),d(i,j,k),ans(i,j,k)
     end if
         end do
   end do
 end do
 return 
 end