How to find the nearest matrix between two matrices?

Find the nearest row matching between matrix.

I have a matrix

A = [2013 03 17 1 6 0]; % 1x6 double

I have another matrix

B = [2013 3	17 0 5 1.012; 2013 3 17 1 6 20.47]; % 4x6 double

I want to find the index of the nearest matrix A in B.

Can anyone please help?

Any help will be greatly appriciated.

Answer 1

[Rik]

Convert each row to a date format (either datetime or datenum).

After that you can subtract one from the other, use abs and min to find the smallest difference. Use the second output of min to find the index of the smallest difference.

[Stephen23]

A = [2013,3,17,1,6,0]; % 1x6 double
B = [2013,3,17,0,5,1.012; 2013,3,17,1,6,20.47]; % 4x6 double

The best way of storing timestamps is as DATETIME objects:

Adt = datetime(A)

Adt = datetime
   17-Mar-2013 01:06:00

Bdt = datetime(B)

Bdt = 2×1 datetime array
   17-Mar-2013 00:05:01
   17-Mar-2013 01:06:20

Then just use ABS and MIN exactly as Rik recommended:

[~,idx] = min(abs(Adt-Bdt))

idx = 2

Bdt(idx)

ans = datetime
   17-Mar-2013 01:06:20

Answer 2

[Abderrahim. B]

clear

A = [2013,3,17,1,6,0]; % 1x6 double
B = [2013,3,17,0,5,1.012; 2013,3,17,1,6,20.47]; % 4x6 double
A = datetime(A) ;
B = datetime(B) ;

minSize_B = max(size(B)) ;

nearestAB  = [] ;
for ii = 1:minSize_B
    nearestAB = [nearestAB abs(A - B(ii))] ;
end
[~, nearestB_indx] = min(nearestAB) % Means, the 4th row in B

nearestB_indx = 2

nearestB = B(nearestB_indx)

nearestB = datetime
   17-Mar-2013 01:06:20

[MP]

I see it works fine in this case, but not always. It is very specific solution.

Let me put naother example and edit my question.

[MP]

In this case, the nearest date is

2013 3 17 1 6 20.47

but, it takes the first index in this case.

[Abderrahim. B]

Thought vectors are numeric arrays not date time ..

Edited my answer, check it out.

[Rik]

@MP did you see my answer? Stephen already implemented it for you in a comment.

[MP]

Yes, @Rik, thanks for helping. I was trying how to implement it but @Stephen23's comment did a great help.