[問題] 以可調步幅法解ODE-IVP

看板Fortran作者shaufire (二天一流)時間15年前 (2009/04/27 18:19)推噓0(0推 0噓 2→)

留言2則, 1人參與討論串1/1

各位版上的朋友大家好小弟第一次在這裡發文，望各位多多包涵 ^ ^a 問題是關於使用IMSL庫存函式IVPAG解ODE-IVP(一階常微分方程組) ODE寫於函式CODE，計算所需的起始值和欲計算的y(t)寫在主程式內以下為部分程式碼：(使用Visual Fortran90撰寫) -- PROGRAM MAIN USE IMSL IMPLICIT NONE INTEGER, PARAMETER :: N = 2 ! No. of eqns INTEGER, PARAMETER :: NPARAM = 50 ! no. of input entries INTEGER MODE, I INTEGER IDO, IEND, NOUT REAL TI, TF, Y10, Y20, TFI REAL PARAM(NPARAM) REAL, PARAMETER :: TOLERR = 1.0E-4 INTEGER, PARAMETER :: NUMPT = 20 DATA TI, TF, Y10, Y20 /0.0, 1.0, 1.0, 0.0/ REAL Y(N), A(1,1), T ! A is not uesd since the ODEs is explicit REAL, EXTERNAL :: CODE, CODEJ ! Required for IVPAG and IVPRK c Initialization: CALL SSET(NPARAM, 0.0, PARAM, 1) IDO = 1 T = TI TFI = 0.0002 Y(1) = Y10 Y(2) = Y20 ... (從略) SELECT CASE (MODE) CASE (1) PRINT*, 'Use Adams-Moulton-Gear method' DO I = 1, NUMPT+1 CALL IVPAG(IDO, N, CODE, CODEJ, A, T, TFI, TOLERR, PARAM, Y) TFI = TFI + (TF - TI)/REAL(NUMPT) IF (TFI .EQ. TF) THEN IDO = 3 ELSE WRITE(*,100) T, Y END IF END DO CASE (2) ... (從略) END SELECT 100 FORMAT(3E16.4) END SUBROUTINE CODE(N, T, Y, DIFFY) IMPLICIT NONE INTEGER N REAL T, Y(N), DIFFY(N) DIFFY(1) = -5.005E2*Y(1) + 4.995E2*Y(2) DIFFY(2) = 4.995E2*Y(1) - 5.005E2*Y(2) RETURN END SUBROUTINE SUBROUTINE CODEJ(N, T, Y, DIFFY) ! Not used IMPLICIT NONE INTEGER N REAL T, Y(N), DIFFY(N,*) RETURN END SUBROUTINE -- 在編譯程式的時候出現了以下訊息： Warning: In the call to IVPAG, actual argument #3 does not match the type and kind of the corresponding dummy argument. CALL IVPAG(IDO, N, CODE, CODEJ, A, T, TFI, TOLERR, PARAM, Y) ---------------------------------^ Warning: In the call to IVPAG, actual argument #4 does not match the type and kind of the corresponding dummy argument. CALL IVPAG(IDO, N, CODE, CODEJ, A, T, TFI, TOLERR, PARAM, Y) 程式計算出來的結果似乎沒有問題不過實在是對這警告訊息有點介意XD 想請問版上高手們這警告訊息是不是來自於我宣告變數或函式有錯？應該要怎樣修改才不會有這問題呢？ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 59.112.36.25