[問題] subroutine的問題

看板Fortran作者joe1121111 (bsyoung)時間13年前 (2011/05/19 00:05)推噓0(0推 0噓 10→)

留言10則, 3人參與討論串1/1

不好意思又來發問了這個問題是用矩陣去解四元一次聯立方程式程式可以跑了但是我寫的subroutine backward(將矩陣右上方部分消掉)一直沒辦法運作以下是主程式跟subroutine c Solving simultaneous equations Program simul4 implicit none integer maxdim, ndim, pivot_c, x parameter(maxdim=100) real*8 aug(maxdim, maxdim+1) ndim=4 aug(1,1)=1; aug(1,2)=1; aug(1,3)=1; aug(1,4)=1; aug(1,5)=4 aug(2,1)=2; aug(2,2)=1; aug(2,3)=1; aug(2,4)=1; aug(2,5)=5 aug(3,1)=1; aug(3,2)=1; aug(3,3)=2; aug(3,4)=1; aug(3,5)=5 aug(4,1)=1; aug(4,2)=1; aug(4,3)=1; aug(4,4)=2; aug(4,5)=6 call displayMatrix(aug,ndim,ndim+1,maxdim,maxdim+1) do pivot_c=1, ndim call eliminatePivotColumn(aug,maxdim,maxdim+1,ndim,pivot_c) call displayMatrix(aug,ndim,ndim+1,maxdim,maxdim+1) end do do x=1, ndim call backward(aug,maxdim,maxdim+1,ndim,x) call displayMatrix(aug,ndim,ndim+1,maxdim,maxdim+1) end do stop End c---------------------------------------------------------- subroutine backward(matrix, ndim, x ,m_max,n_max) implicit none integer col, pivot_r, i, j, m_max, n_max, ndim, x real*8 matrix(m_max, n_max), tmp(n_max) c backward x=1 do i=x, ndim do j=i+1, ndim+1 tmp(1)=matrix(i,j) matrix(i,j)=matrix(i,j)-tmp(1)*matrix(i+1,j) end do end do do i=x, ndim do j=i+2, ndim+1 tmp(1)=matrix(i,j) matrix(i,j)=matrix(i,j)-tmp(1)*matrix(i+2,j) end do end do do i=x, ndim do j=i+3,ndim+1 tmp(1)=matrix(i,j) matrix(i,j)=matrix(i,j)-tmp(1)*matrix(i+3,j) end do end do return end 他display的矩陣是只有經過第一個subroutine 的eliminate的矩陣第二個subroutine好像沒有運算到為什麼會這樣? -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 118.171.114.61 ※ 編輯: joe1121111 來自: 118.171.114.61 (05/19 00:08)