關於forall和where在程序裡使用的問題

max533

下面是我的一個程序，但我不清楚為什麼forall和where在這個案例上的應用。為什麼forall可以，但where不行。
分別在line57和line60，如果使用forall的話，在螢幕上就只能顯示4個字的字串。如果使用where的話，在螢幕上就只能顯示3個字的字串。
程式的相關附件在壓縮檔中。
先在這邊感謝各位高手。

[Fortran] 纯文本查看 复制代码

program add_gamit_station_info
implicit none

integer :: count,stat,err,err2,i,stat2,stat3,k,stat4
character :: example_line*300,filename*30,line*300,site*4
character (len=300),allocatable :: example_line_array(:)
character (len=4),allocatable :: example_site_array(:) 

open (11,file='list.txt')
close (11,status='delete')
call system ('dir /b *.info > list.txt')
open (11,file='list.txt')
open (22,file='station_cwb.info.db')
open (33,file='station_expt.info.db')
!---------------------------------------------> to check array size
do k=1,5,1
  read (22,*,iostat=stat4) example_line
end do
count=0
stat=0
do while (stat==0)
  read (22,'(a300)',iostat=stat) example_line
  if (stat/=0) exit
  count=count+1
end do
!---------------------------------------------> to check array size
rewind (22)
!---------------------------------------------> to allocate the example_line_array & example_site_array
allocate (example_line_array(count),stat=err)

if (err==0) then 
  write (*,*) 'The example_line_array allocated sucessfully.'
else if (err/=0) then 
  write (*,*) 'The example_line_array failed to allocate.'
end if

allocate (example_site_array(count),stat=err2)

if (err2==0) then
  write (*,*) 'The example_site_array allocated sucessfully.'
else if (err/=0) then 
  write (*,*) 'The example_site_array failed to allocate.'
end if 
!---------------------------------------------> to allocate the example_line_array & example_site_array

!---------------------------------------------> to assign array value from station_cwb.info into example_line_array
do k=1,5,1
  read (22,*,iostat=stat4) example_line
end do

do i=1,count,1
  read (22,'(a300)') example_line_array(i)
end do
!---------------------------------------------> to assign array value from file into example_line_array

!---------------------------------------------> to assign array value from example_line_array(2:5) into example_site_array
!where (example_site_array/=' ') example_site_array=example_line_array(2:5)


forall (i=1:count:1) example_site_array(i)=example_line_array(i)(2:5)
!---------------------------------------------> to assign array value from example_line_array(2:5) into example_site_array
do i=1,count,1
  write (*,*) example_site_array(i)
end do
rewind (22)
!---------------------------------------------> to check whether is new site.
!---------------------------------------------> if it is a new site , we write down the name of site.
!---------------------------------------------> if it isn't a new site , we skip site.                               
stat2=0
do while (stat2==0)
  read (11,*,iostat=stat2) filename
  if (stat2/=0) exit
  open (44,file=trim(filename))
  
  do k=1,5,1
      read (44,*,iostat=stat4) line
  end do
  
  stat3=0
  do while (stat3==0)
    read (44,'(a300)',iostat=stat3) line 
    if (stat3/=0) exit
    site=line(2:5)
    if (any(example_site_array==site)) cycle
    write (33,'(a4)') site                  
  end do
end do 
!---------------------------------------------> to check whether is new site.
!---------------------------------------------> if it is a new site , we write down the name of site.
!---------------------------------------------> if it isn't a new site , we skip site.
close (11)
close (22)
close (33)
close (44)
end program

fcode

改为
where (example_site_array/=' ') example_site_array(:)=example_line_array(:)(2:5)
你那样写的话，编译器会认为 (2:5) 是数组片段，而不是子字符串。

max533

fcode 发表于 2015-8-24 21:21
改为
where (example_site_array/=' ') example_site_array(:)=example_line_array(:)(2:5)
你那样写的话， ...

感謝fcode的說明，居然犯了這種錯誤，感謝fcode提醒。