how to assign ID

Hi

I want to find assigned point in fram k+1 the below 8x6 logical matrix (locations where its 1). I have got the below matrix after doing munkres algorithm to find the shortest distance.

matrix =[1 0 0 0 0 0
         0 0 0 1 0 0
         0 0 0 0 1 0
         0 0 0 0 0 0
         0 1 0 0 0 0
         0 0 1 0 0 0
         0 0 0 0 0 1
         0 0 0 0 0 0]
     

then i want to check if elements of cost matrix below is less than threshold (eg:20)

3.78269075791294	278.548721531889	77.0483578413583	319.089385747004	72.3994091374370	341.243380767610
320.592670775924	502.410281024145	391.613587309557	1.70715905820170	252.111134589054	400.821864561790
71.6724364458890	291.477613257434	136.358877273355	255.879901151185	3.59902165178262	306.236057160077
317.477686638447	585.025649185487	391.175631697579	230.260817991186	292.577668505920	563.618080442638
278.854570295432	3.81058814489312	227.217240119693	503.731220780547	291.669067062947	221.356635566811
81.4885326821510	230.323795489155	5.96133868606709	397.677352526140	145.542252400360	345.981529098511
361.919791413408	292.340013620655	375.773820610502	349.149722492680	307.422993601501	82.3983010728358
181.860607286048	317.121151668522	235.113062861616	186.520583928155	107.847881217621	249.910660475223

• if the threshold less than 20, i want to link points in k+1 frame with the same ID number of the points in frame k+1. (The above matrix is output of pdist2, so the small numbers as difference suggest that it was the same object as in frame k, ie it hasnt displaced drastically.)

• if not, use new ID number.

[James Tursa]

What would be the desired output for your example?

[karishma koshy]

For example if I have 2 objects detected in k and 3 objects detected in k+1 frame then as follows:

ID 
1 
2 
1 
2 
3

Answer 1

[Vinai Datta Thatiparthi]

Hi Karishma!

It’s a bit unclear to me from the description how you’re getting this output. I’m assuming that you are facing an issue with manipulating the matrices.

Start with loading the values into variables. Use the relational operator to identify the indices in the cost matrix that don’t satisfy the threshold condition –

matValues = []; % Matrix values 
cost= []; % Cost values
loc = cost<20; % Results in an 8x6 logical array

After this step, you may use simple if-else statements and indexing through the matrices to get your expected values.

Hope this helps!