关于fortran的分段错误
问题遇到的现象和发生背景
出现了分段错误，一直找不到错误原因，错误格式如下。
数据格式如下（一部分）
数据为：文件编号（24835），纬度（60.015），经度（101.802），高度（5640），雷达反射率（-33.884），C1mask（0），C4type（0），温度（235.9），陆地-大气判断系数（0）
在对这些数据进行处理的时候首先编写了如下的fortran程序：
program sample
implicit none
!-9=missing / 0=clear / 1=warm water / 2=supercooled water /
! 3=3d ice / 4=2d plate / 5=mixture of 3d ice and 2d plate /
! 6=liquid drizzle / 7=mixed-phase drizzle / 8=rain / 9=snow /
! 10=water+liquid driz / 11=water+rain / 12=mixed-phase /13=unknown )
integer::i,k,nx,n=40000000,nalt=83
real::la,lo,lonmin,lonmax,latmax,latmin,count_record
real::ice,snow,clear,warm_water,supercooled_water,twod_plate,mixture,Mixed_phase_drizzle,rain
real::ice_per,snow_per,clear_per,warm_water_per,supercooled_water_per,twod_plate_per,mixture_per
real::Mixed_phase_drizzle_per,rain_per
integer,dimension(:),allocatable::profile_number
real,dimension(:),allocatable::lon,lat
real,dimension(:,:),allocatable::ref,c1mask,alt,c4type,d_n,temp
allocate(profile_number(1:n))
allocate(lat(1:n))
allocate(lon(1:n))
allocate(ref(1:n,1:nalt))
allocate(alt(1:n,1:nalt))
allocate(c4type(1:n,1:nalt))
allocate(c1mask(1:n,1:nalt))
allocate(d_n(1:n,1:nalt))
allocate(temp(1:n,1:nalt))
write(*,*) 'allocated'
open(unit=65,file='arctic_cmask_type_2007.txt',status='old')
write(*,*)"already open"
i=0
do
i=i+1
do k=nalt,1,-1
read(65,*,end=1000)profile_number(i),lat(i),lon(i),alt(i,k),ref(i,k),c1mask(i,k),c4type(i,k),temp(i,k),d_n(i,k)
end do
write(*,*)i
end do
1000 close(65)
nx=i-1
write(*,*)nx
write(*,*)"already"
!--------------------------------------------
open(unit=66,file='per1.txt',status='replace')
open(unit=67,file='per2.txt',status='replace')
open(unit=68,file='per3.txt',status='replace')
latmin=-90
latmax=-88
count_record=0
do la=-90,90,2
write(*,*)la
lonmin=-180
lonmax=-178
do lo=-180,180,2
do i=1,nx,1
if(latmin<=lat(i).and.latmax>lat(i))then
if(lonmin<=lon(i).and.lonmax>lon(i))then
count_record=count_record+1
!---------------------------------------------------------------------------
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if (c4type(i,k)==3)then
ice=ice+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(c4type(i,k)==9)then
snow=snow+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(c4type(i,k)==0)then
clear=clear+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(c4type(i,k)==1)then
warm_water=warm_water+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(c4type(i,k)==2)then
supercooled_water=supercooled_water+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(c4type(i,k)==4)then
twod_plate=twod_plate+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(c4type(i,k)==5)then
mixture=mixture+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(c4type(i,k)==7)then
Mixed_phase_drizzle=Mixed_phase_drizzle+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(c4type(i,k)==8)then
rain=rain+1
end if
exit
end if
end do
end if
end if
end do
ice_per=100*ice/count_record
snow_per=100*snow/count_record
clear_per=100*clear/count_record
warm_water_per=100*warm_water/count_record
supercooled_water_per=100*supercooled_water/count_record
twod_plate_per=100*twod_plate/count_record
mixture_per=100*mixture/count_record
Mixed_phase_drizzle_per=100*Mixed_phase_drizzle/count_record
rain_per=100*rain/count_record
if(count_record>0)then
write(66,'(2F10.1,3F10.3)')la-90,lo-180,ice_per,snow_per,rain_per
write(67,'(2F10.1,3F10.3)')la-90,lo-180,clear_per,warm_water_per,supercooled_water_per
write(68,'(2F10.1,3F10.3)')la-90,lo-180,twod_plate_per,mixture_per,Mixed_phase_drizzle_per
end if
count_record=0
snow=0
ice=0
clear=0
warm_water=0
supercooled_water=0
twod_plate=0
mixture=0
Mixed_phase_drizzle=0
rain=0
lonmin=lonmin+2
lonmax=lonmax+2
end do
latmin=latmin+2
latmax=latmax+2
end do
stop
end program sample
能正常运行。
但是现在执行如下程序 主框架没有变只是变了一个判断条件就会出现上边所示的分段错误。
program sample
implicit none
!-9=missing / 0=clear / 1=warm water / 2=supercooled water /
! 3=3d ice / 4=2d plate / 5=mixture of 3d ice and 2d plate /
! 6=liquid drizzle / 7=mixed-phase drizzle / 8=rain / 9=snow /
! 10=water+liquid driz / 11=water+rain / 12=mixed-phase /13=unknown )
integer::i,k,j,nx,n=30000000,nalt=83
real::la,lo,lonmin,lonmax,latmax,latmin,count_record
real::precipitation,precipitation_per,snowfall_real,snowfall_real_per
integer,dimension(:),allocatable::profile_number
real,dimension(:),allocatable::lon,lat
real,dimension(:,:),allocatable::ref,c1mask,alt,c4type,d_n,temp
allocate(profile_number(1:n))
allocate(lat(1:n))
allocate(lon(1:n))
allocate(ref(1:n,1:nalt))
allocate(alt(1:n,1:nalt))
allocate(c4type(1:n,1:nalt))
allocate(c1mask(1:n,1:nalt))
allocate(d_n(1:n,1:nalt))
allocate(temp(1:n,1:nalt))
write(*,*) 'allocated'
open(unit=65,file='arctic_cmask_type_2007DJF.txt',status='old')
write(*,*)"already open"
i=0
do
i=i+1
do k=nalt,1,-1
read(65,*,end=1000)profile_number(i),lat(i),lon(i),alt(i,k),ref(i,k),c1mask(i,k),c4type(i,k),temp(i,k),d_n(i,k)
end do
write(*,*)i
end do
1000 close(65)
nx=i-1
write(*,*)nx
write(*,*)"already"
!--------------------------------------------
open(unit=66,file='snowfall_per.txt',status='replace')
open(unit=67,file='gound_snowfall_per.txt',status='replace')
open(unit=68,file='precipitation_per.txt',status='replace')
latmin=-90
latmax=-88
count_record=0
do la=-90,90,2
write(*,*)la
lonmin=-180
lonmax=-178
do lo=-180,180,2
do i=1,nx,1
if(latmin<=lat(i).and.latmax>lat(i))then
if(lonmin<=lon(i).and.lonmax>lon(i))then
count_record=count_record+1
!---------------------------------------------------------------------------
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(ref(i,k)>-10)then
precipitation=precipitation+1
end if
exit
end if
end do
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(ref(i,k)>-10.and.temp(i,k)<275.15)then
snowfall_real=snowfall_real+1
end if
exit
end if
end do
end if
end if
end do
precipitation_per=precipitation*100/count_record
snowfall_real_per=snowfall_real*100/count_record
if(count_record>100)then
write(68,'(2F10.1,2F10.3)')la-90,lo-180, precipitation_per,snowfall_real_per
end if
count_record=0
snowfall_real=0
precipitation=0
lonmin=lonmin+2
lonmax=lonmax+2
end do
latmin=latmin+2
latmax=latmax+2
end do
stop
end program sample
两段代码根本区别就是
第一个代码：
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if (c4type(i,k)==3)then
ice=ice+1
end if
exit
end if
end do
而第二个代码：
do k=1,nalt,1
if(d_n(i,k)==0.and.d_n(i,k-1)==3)then
if(ref(i,k)>-10.and.temp(i,k)<275.15)then
snowfall_real=snowfall_real+1
end if
exit
end if
end do
不知为什么加一个判断条件就会出现分段错误，并且不知道怎么改。
有没有可以帮忙解决一下这个问题，经常会碰到这类问题只能一点一点试，有的时候会正常，但不知道为什么。
do 循环不能使用负数值,程序编译会报错。比如：
想产生 n 为-180，180，2 的序列，可以使用n 为 0，360，2 ，循环体内 n-180.
段错误需要调试，不仅要代码，还要输入文件。
你这个肯定会数组越界
如果 .and. 之前的那个条件不满足，后面的这个可能不会参与计算，也就不报错。