[問題] fortran 數字太大跑出來都是****的星號

看板Programming作者Ecampus (7.7)時間7年前 (2017/10/05 00:57)推噓1(1推 0噓 11→)

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※ [本文轉錄自 Fortran 看板 #1PrHBDIp ] 作者: Ecampus (7.7) 看板: Fortran 標題: [問題] 數字太大導致跑出來都是"****"的星號Q_Q 時間: Thu Oct 5 00:56:42 2017 不好意思我最近在改寫一個FORTRAN的程式碼(是關於把汙染物放進河川裡) 我把汙染物的初始濃度設定為1000000000 (1E9) 然後數據跑出來很多都是*********星號(代表數據過大) 我覺得這應該是我給fortran的空間不夠但我修改之後還是沒辦法修正結果還是會跑出*********星號我想可能是我修改錯誤想請大家幫忙看一下我可能錯在哪裡相關code如下: PROGRAM DISPERSION IMPLICIT NONE REAL*8 :: CC(300), Xstop(10), Xgauge(10), UU(10), EE(10) REAL*8 :: INI_X, END_X, E, U, DE, DX REAL*8 :: T, TT, DT INTEGER :: N, I, II, IT, ITT, ITW, WT, NO_S CHARACTER(LEN=100) :: filename CHARACTER(LEN=40) :: ext=".dat" !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! INPUT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CHARACTER(LEN=20000) :: casename='test123' ! directory for saveing files INI_X = 0. ! initial of x END_X = 1700. ! end of x DX = 10. N = INT((END_X-INI_X)/DX)+1 ! number of node T = 0. ! the same unit as U and E ITW = 50 ! iteration steps duration to write TT = 3120. ! end time of T DT = 0.1 CC(1) = 1E9 ! concentration of first node at time = 0.0 CC(N) = 0. ! concentration of last node at time = 0.0 DE = 0.0000008333333333333333333333 NO_S = 3 ! number of station !!!!! stations !!!!! Xstop(1) = 0. ! first station Xstop(2) = 850. ! second station Xstop(3) = 1700. ! third station !!!!! velocity, U !!!!! UU(1) = 0.49 ! velocity between 1st and 2nd station UU(2) = 0.49 ! velocity between 2nd and 3rd station !!!!! diffusion coefficient, E !!!!! EE(1) = 6.5 ! coefficient between 1st and 2nd station EE(2) = 6.5 ! coefficient between 2nd and 3rd station !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! END SETTING !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! OPEN(101, FILE='time'//ext, STATUS='UNKNOWN') DO I = 1, NO_S II = 1 DO WHILE ((INI_X+float(II-1)*DX-Xstop(I)) .LE. 0.) II = II+1 ENDDO Xgauge(I) = II-1 WRITE(filename,'(I3.3)') I ! filename contains the time you write OPEN(301,file='station'//TRIM(filename)//ext,STATUS='unknown') ENDDO DO I=2, N-1 CC(I)=0. ENDDO IT = 0 ITT = 0 WT = 0 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! start !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! WRITE(101,102) T 102 FORMAT(F100.95) WRITE(filename,'(I5.5)') WT ! filename contains the time you write OPEN(201,file=TRIM(filename)//ext,STATUS='unknown') WRITE(201,202) (CC(I),I=1,N) 202 FORMAT(2X,10000F8.4) DO II = 1, NO_S WRITE(filename,'(I3.3)') II ! filename contains the time you write OPEN(301,file='station'//TRIM(filename)//ext,STATUS='old') WRITE(301,302) CC(INT(Xgauge(II))) 302 FORMAT(F8.4) ENDDO OPEN(401,file='x'//ext,STATUS='unknown') DO I = 1, N WRITE(401,*) (INI_X+(I-1)*DX) ENDDO 12 T=T+DT IT=IT+1 ITT = ITT+1 DO WHILE (T .LT. TT+DT) DO I=2,N-1 IF ((I-1)*DX+INI_X .GE. Xstop(1) .AND. (I-1)*DX+INI_X .LT. Xstop(2)) THEN U = UU(1) E = EE(1) ELSEIF ((I-1)*DX+INI_X .GE. Xstop(2) .AND. (I-1)*DX+INI_X .LT. Xstop(3)) THEN U = UU(2) E = EE(2) ENDIF CC(I)=CC(I)+E*DT*(CC(I+1)-2*CC(I)+CC(I-1))/DX/DX-& U*DT*(CC(I+1)-CC(I-1))/2./DX-& DE*DT*CC(I) CC(N+1) = CC(N-1) ENDDO IF(IT.LT.ITW) GOTO 12 WRITE(101,102) T WT = WT+1 WRITE(filename,'(I5.5)') WT ! filename contains the time you write OPEN(201,file=TRIM(filename)//ext,STATUS='unknown') WRITE(201,202) (CC(I),I=1,N) IT = 0 DO II = 1, NO_S WRITE(filename,'(I3.3)') II ! filename contains the time you write OPEN(301,file='station'//TRIM(filename)//ext,STATUS='old',ACCESS='APPEND') WRITE(301,302) CC(INT(Xgauge(II))) ENDDO WRITE(*,15) T 15 FORMAT(1X,'output data at time = ',F10.4) GOTO 12 ENDDO CLOSE(101); CLOSE(201); CLOSE(301); CLOSE(401); call system('mkdir ' // casename) call system('move *.dat ' // casename) STOP END -- ※ 發信站: 批踢踢實業坊(ptt.cc), 來自: 125.230.80.110 ※ 文章網址: https://www.ptt.cc/bbs/Fortran/M.1507136205.A.4B3.html ※ 發信站: 批踢踢實業坊(ptt.cc) ※ 轉錄者: Ecampus (125.230.80.110), 10/05/2017 00:57:14

[問題] fortran 數字太大 跑出來都是****的星號

[問題] fortran 數字太大跑出來都是****的星號