Sorting A 2 Dimensional Array

[ceaser]

:BangHead:Hi

I wonder if somebody can help me:sign0085:

I have a 2 dimensional array : Dim Type(Offset,Level) OGL(0) as double which is declared under my Global Sub.

Now because of different calculations, i.e Toe Points, Shouder Break Points, Surface, Shoulders, Kerbs, etc., the Offsets and levels are all mixed up, i.e they do not run from small offsets to large offsets.

i.e.

(-20,1234); (10,1211); (-10,1212); (5,1213); (18,1211.5); (-2,1213)...etc.

Now what I want to do is to sort the Offsets from small to large, but the levels must stay with the Offsets...i.e.

(-20,1234); (-10,1212); (-2;1213); (5,1213); (18,1211.5);...etc.:BangHead:

Can this be done or is there maybe a function in B4PPC that I do not know of. I know of the "Sort" function, but that is for a 1 dimensional array.:BangHead:

Thanks
Michael

 

[mjcoon]

I appreciate that this is rather a provocative reply, but if the data had been in a table then the rows could be sorted by any column...

HTH (!) Mike.

 

[specci48]

Maybe it's possible to split the 2-dimensional array into two 1-dimensional.
The first array contains the offset, the second contains the level.

With this and the help of agrahams ArrayEx.dll you can use the method SortKeysAndItems sorting both arrays as requested.


specci48

 

[Erel]

Are the offset values unique? If yes then you can use a Hashtable and an ArrayList to sort the items.

 

[ceaser]

Gentlemen

I am most obliged for your help:sign0188:

My problem has been solved.

Regards
Michael

 

[mjcoon]

My problem has been solved.

Aw, come on, tell us what the solution was...

Mike.

 

[ceaser]

Hi mjcoon

It's a short little routine:

'Sort The Offsets i1=number of Offsets & Levels
For i4=1 To i1-1
For i5=i4+1 To i1
If Offset(i4)>Offset(i5) Then
TOffset=Offset(i5) :TLevel=Design(i5)
Design(i5)=Design(i4) :Offset(i5)=Offset(i4)
Design(i4)=TLevel :Offset(i4)=TOffset
End If
Next i5
Next i4

 

[DarkMann]

Faster Sort

Hi Ceaser

If your list of points is more than about 100, then your sort will be incredibly slow. As I have never gotten on well with a true recursive quicksort and never tried in B4P, I use the O-Sort written by Erik Oosterwal. Information used to be on geocities, but it has been taken down and almost forgotten.

It is an order of magnitude or more quicker than your bubble sort. The following code should drop into your program, but I have not tested it. It has been pulled from another program and changed to match your variable names.

'o-sort for i1 entries
SngPhi = 0.78
SngFib = i1 * SngPhi
s = Int(SngFib)
Do While (s > 0)
    For i4 = 1 To i1 - s
        If Offset(i4)>Offset(i4 + s) Then
            TOffset=Offset(i4 + s)
            TLevel=Design(i4 + s) 
            Design(i4 + s)=Design(i4) 
            Offset(i4 + s)=Offset(i4) 
            Design(i4)=TLevel 
            Offset(i4)=TOffset
        End If
    Next
SngFib = SngFib * SngPhi
s = Int(SngFib)
Loop

Hope it's useful,

David