MATLAB: How to replace values of a large array by the values of a smaller one

Question

I have two tables T1 and T2 with identical number of columns but different number of raw.

The x,y,z columns from both tables were created as below:

clear all;
close all;
XSTART=5;
XEND=20;
YSTART=5;
YEND=15;
STEP1=1;
STEP2=5;
%*******************            CREATE TABLE1          ********************
xvector1 = XSTART:STEP1:XEND;
yvector1 = YSTART:STEP1:YEND;
numX1 = numel(xvector1);  
numY1 = numel(yvector1);
yvector1 = repmat(yvector1(:),numX1,1);
xvector1 = repmat(xvector1   ,numY1,1);
COORDINATES1= [xvector1(:) yvector1];
VALUE1=(1:1:numX1*numY1)';
VALUE1(1:end,1)=10;
T1=[COORDINATES1 VALUE1];
%*******************            CREATE TABLE2          ********************
xvector2 = XSTART:STEP2:XEND;
yvector2 = YSTART:STEP2:YEND;
numX2 = numel(xvector2);  
numY2 = numel(yvector2);
yvector2 = repmat(yvector2(:),numX2,1);
xvector2 = repmat(xvector2   ,numY2,1);
COORDINATES2= [xvector2(:) yvector2];
VALUE2 =(1:numX2*numY2)';
T2=[COORDINATES2 VALUE2];

Now I want to create a table T3 replacing the values of the third column from T1 by the values of the third column from T2 with the same x,y- coordinate.

The expected T3 after proper substitution will have the following components:

5  5  1
5  6  10
5  7  10
5  8  10
5  9  10
5  10  2
5  11  10
5  12  10
5  13  10
5  14  10
5  15  3
6  5  10
6  6  10
6  7  10
6  8  10
6  9  10
6  10  10
6  11  10
6  12  10
6  13  10
6  14  10
6  15  10
7  5  10
7  6  10
7  7  10
7  8  10
7  9  10
7  10  10
7  11  10
7  12  10
7  13  10
7  14  10
7  15  10
8  5  10
8  6  10
8  7  10
8  8  10
8  9  10
8  10  10
8  11  10
8  12  10
8  13  10
8  14  10
8  15  10
9  5  10
9  6  10
9  7  10
9  8  10
9  9  10
9  10  10
9  11  10
9  12  10
9  13  10
9  14  10
9  15  10
10  5  4
10  6  10
10  7  10
10  8  10
10  9  10
10  10  5
10  11  10
10  12  10
10  13  10
10  14  10
10  15  6

and so on.

I hope someone knows how to do it.

Thanks in advance for your help

Emerson

Answer 1

Is this what you mean:

T3 = T1;
[c, ia, ib] = intersect(T2(:, 1:2), T3(:, 1:2), 'rows');
T3(ib, 3) = T2(ia, 3)