在fortran中查找重复记录 [英] finding duplicate records in fortran
问题描述
我试图通过将输出导出为csv来查找这些集合，并将其导入到MS Access，那么发现这些集合的查询需要10秒左右才能运行。我写了一个代码 http://rosettacode.org/wiki/Remove_duplicate_elements#Fortran this（ 线性搜索？），但百万记录在10分钟左右没有完成，我刚刚放弃了这种方法。
我现在想的方法是调整排名/排序例程 slatec 或订单包，我认为这比我的原始代码更好。但我想知道这样的事情是否已经完成，我可以下载，或者如果有更好的方法。
编辑： 从原始数据记录映射到这个缩减集。我想要像imap（1：n）这样的映射数组，其中imap（1），imap（4），imap（5）具有相同的值，如果这些浮点数是pt。原始记录1,4和5中的值是相同的。希望这不会太偏离我原先所说的......
这就是我最终做的事情。 。我从 ORDERPACK 取得了代码 mrgrnk ，并适合我的目的。下面的子程序 findmap 似乎正在做我想做的事。
module fndmap
use m_mrgrnk，only：mrgrnk
implicit none
包含
子程序findmap（stkprm，stkmap）
！给出二维真实数组stkprm，找到如下所示的映射：
！
！ （相同的记录分配有相同的索引）
！ stkmap（i）== stkmap（j）iff stkprm（：，i）== stkprm（：，j）
！ （订单保存）
！如果我< j和stkmap（i）/ = stkmap（j），则stkmap（i）< stkmap（j）
！ （新索引是连续的）
！ set（stkmap）== {1,2，..，maxval（stkmap）}
！
real，dimension（：，:)，intent（in）:: stkprm
整数，维（:)，intent（out）:: stkmap
整数，维（size（stkprm， 2））:: irngt
integer，dimension（size（stkprm，2））:: iwork
integer :: nrec，i，j
nrec = size（stkprm，2）
！查找每条记录的等级，重复记录保存
调用ar_mrgrnk（stkprm，irngt）
！构建iwork数组，其中包含原始数组的索引，其中
！记录是相同的，并且索引是youguest
i = 1
do（i <= nrec）
do j = i + 1，nrec
if（any（stkprm ，irngt（i））/ = stkprm（：，irngt（j））））exit
enddo
iwork（irngt（i：j-1））= minval（irngt（i：j-1 ））
i = j
enddo
！现在构建地图，其中stkmap（i）显示新数组
的索引！如果（i == iwork（i））然后
j = j + 1 $ b $保留原始订单
j = 0
do i = 1，nrec
b stkmap（i）= j
else
stkmap（i）= stkmap（iwork（i））
endif
enddo
结束子程序
递归子程序ar_mrgrnk（xdont，irngt）
！就像ORDERPACK的mrgrnk一样，除了数组是2-b
！每行按第一个字段排序，然后第二个等等
real，dimension（:, :)，intent（in）:: xdont
整数，维度（:)，intent（out），目标:: irngt
integer，dimension（size（xdont，2））:: iwork
整数:: nfld，nrec
整数:: i，j
整数，dimension（:)，pointer :: ipt
nfld = size（xdont，1）
nrec = size（xdont，2）
！排名第一场
打电话mrgrnk（xdont（1，:)，irngt）
！如果只有一个字段，如果（nfld == 1）返回
，则完成
！检查级别以查看多个记录是否具有相同的
！ （1，irngt（i））的第一场
i = 1
的值为（i <= nrec）
do j = i + 1，nrec
/ = xdont（1，irngt（j）））退出
enddo
！如果一对一，如果（j-1> i）然后
，则不做任何
！如果多对一，
！收集那些许多，然后排列他们
调用ar_mrgrnk（xdont（2 :, irngt（i：j-1）），iwork）
！根据这些字段重新排列我的排名到右边
ipt => irngt（i：j-1）
ipt = ipt（iwork（1：ji））
endif
i = j
enddo
if（associated（ipt）） nullify（ipt）
结束子程序
结束模块
I have a data approximately a million record, each record have 6 floating point number. I want to find sets of records who share identical six values, and ideally I want to do it in Fortran since the rest of processing is done in Fortran. What would be the recommended approach for this? At the end i want to have mapping from original index to new index which is condensed version of these dataset without duplicate. Each record has other attributes and i am interested in aggregating those for groups based on the six attributes.
I tried to find those sets by exporting output as csv, import it into MS Access, then a query that finds those sets took 10 seconds or so to run. I wrote a code which does http://rosettacode.org/wiki/Remove_duplicate_elements#Fortran this ("linear search"?), but with million record it didnt complete after 10 min or so, i just abandoned this approach.
Approach I am thinking now is adapting ranking/sorting routine from slatec or orderpack which i assume do better than my crude code. But I am wondering if such things are already done and i can download, or if there is better approach for this.
EDIT:
I said "finding duplicate", but i actually need mapping from original data records to this reduced sets. I want to have mapping array like imap(1:n), where imap(1), imap(4), imap(5) has same values if those 6 float pt. values in original record 1, 4 and 5 are the same. Hope this is not too much a deviation from what I said originally...
This is what I ended up doing... I took code mrgrnk from ORDERPACK , and adapted for my purpose. The subroutine findmap below appears to be doing what I wanted it to do.
module fndmap
use m_mrgrnk, only:mrgrnk
implicit none
contains
subroutine findmap(stkprm, stkmap )
! given 2-d real array stkprm, find a mapping described below:
!
! (identical records are assigned with same index)
! stkmap(i) == stkmap(j) iff stkprm(:,i) == stkprm(:,j)
! (order conserved)
! if i < j and stkmap(i) /= stkmap(j), then stkmap(i) < stkmap(j)
! (new index are contiguous)
! set(stkmap) == {1,2,..,maxval(stkmap)}
!
real,dimension(:,:),intent(in) :: stkprm
integer,dimension(:), intent(out) :: stkmap
integer, dimension(size(stkprm,2)) :: irngt
integer, dimension(size(stkprm,2)) :: iwork
integer :: nrec, i, j
nrec = size(stkprm,2)
! find rank of each record, duplicate records kept
call ar_mrgrnk(stkprm, irngt)
! construct iwork array, which has index of original array where the
! record are identical, and the index is youguest
i = 1
do while(i<=nrec)
do j=i+1,nrec
if (any(stkprm(:,irngt(i))/=stkprm(:,irngt(j)))) exit
enddo
iwork(irngt(i:j-1)) = minval(irngt(i:j-1))
i = j
enddo
! now construct the map, where stkmap(i) shows index of new array
! with duplicated record eliminated, original order kept
j = 0
do i=1,nrec
if (i==iwork(i)) then
j = j+1
stkmap(i) = j
else
stkmap(i) = stkmap(iwork(i))
endif
enddo
end subroutine
recursive subroutine ar_mrgrnk(xdont, irngt)
! behaves like mrgrnk of ORDERPACK, except that array is 2-d
! each row are ranked by first field, then second and so on
real, dimension(:,:), intent(in) :: xdont
integer, dimension(:), intent(out), target :: irngt
integer, dimension(size(xdont,2)) :: iwork
integer :: nfld,nrec
integer :: i, j
integer, dimension(:), pointer :: ipt
nfld=size(xdont,1)
nrec=size(xdont,2)
! rank by the first field
call mrgrnk(xdont(1,:), irngt)
! if there's only one field, it's done
if (nfld==1) return
! examine the rank to see if multiple record has identical
! values for the first field
i = 1
do while(i<=nrec)
do j=i+1,nrec
if (xdont(1,irngt(i))/=xdont(1,irngt(j))) exit
enddo
! if one-to-one, do nothing
if (j-1>i) then
! if many-to-one,
! gather those many, and rank them
call ar_mrgrnk(xdont(2:,irngt(i:j-1)),iwork)
! rearrange my rank based on those fields to the right
ipt => irngt(i:j-1)
ipt = ipt(iwork(1:j-i))
endif
i = j
enddo
if(associated(ipt)) nullify(ipt)
end subroutine
end module
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