How to find the contigous coordinate points between two varaibles datasets and do regression

Folks

I have two data variable sets of different sizes, A (chlorophyll) is 4317x3 matrix of lat, lon, and con. data value and B(SST) is 5851x3 matrix, of same lat, lon, and conc. data value. I want to find the coordinates in A data set that are closest to those B.

Then based on the index locations of those coordinates in the B matrix, extract out the concentration values from that correspond to those coordinates so that I can plot A and B concentration data sets value against one another.

The difficult part is to sort the coordinate locations in the A matrix with those in the B matrix, I would like to find the closest possible coordinate locations between the 2 large marice data sets.

please find the attached link for 2 datsets files

https://drive.google.com/drive/folders/1YuwIcSA4J2KYjCBVEa5zIbF7qqqAKClV?usp=sharing

I have used this code

F = scatteredInterpolant(B(:,1), B(:,2), (1:size(B,1)).', 'nearest');
A_is_nearest_idx = F( A(:,1:2) )
B_closest_to_A = B(A_is_nearest_idx, :)

I find error

kindly help to sort the variables which was of continuous in order for synchronize and interpolate.

Answer 1

[KSSV]

idx = knnsearch(A(:,1:2),B(:,1:2)) ; 
B = B(idx,:) ; 

[Karthik M]

@KSSV

While using the code above I found this error Index in position 2 exceeds array bounds (must not exceed 1).

kindly help

[KSSV]

Which line? I

[Karthik M]

idx = knnsearch(A(:,1:2),B(:,1:2)) ;

[KSSV]

T1 = readtable('chlor.csv') ;
T2 = readtable('sst.csv') ;

idx = knnsearch([T2.(1) T2.(2)],[T1.(1) T1.(2)]) ; 
T2 = T2(idx,:) ;
plot(T1.(1),T1.(2),'.r')
hold on
plot(T2.(1),T2.(2),'ob')

[KSSV]

Your A and B should be the matrices which you said. It sseems you are taking different variables. I have given the code with csv files, check that.

[Karthik M]

Actually I need sorted chlor and sst concentration data value of same coordinates with same number of rows

to perfrom statistical analysis / regression by keeping chlor along y and sst along x axis

[KSSV]

The attched data is time series or data at one time step? What data you have exactly? What regression you want? Spatial or temporal?

[Karthik M]

The attached chlor and SST is of extracted regional MODIS Aqua netcdf time series data

I need spatial regression for chlor concentration data in relationship to that of SST conc.