Add a vector to a matrix if satisfies one condition

I have a random sorted matriz A of coordinates[x, y, z], sorted in the third column

A=

-3.7101 5.9258 9.9850

1.7114 1.9374 6.4446

0.4066 1.2890 3.9829

and another random vector B [x, y, z]

B=

-6.4932 3.3327 5.2881

I want to create a new matrix C, adding vector B to vector A (the position of the new vector does not matter):

C=

-3.7101 5.9258 9.9850

1.7114 1.9374 6.4446

0.4066 1.2890 3.9829

vector B--> -6.4932 3.3327 5.2881

BUT, I want to add the vector, if and only if the values in the third column satisfy the following condition:

6.44 - 1 > 5.2882 > 3.98 + 1

5.44 > 5.28 > 4.98

This means, I want to find in the matrix A the two closest values (in the third column) to B, and compare them in the condition. If the condition is accomplised, add the vector to the matrix. Thank you in advance I really appreciate your help.

I would like just to know how to find those two closest values to B(1,3)= in A and then test the condition.

Answer 1

[Bhaskar R]

 col_3 = A(:, 3); % 3rd column of A
 con = col_3(2)- 1> B(end) >col_3(end)+1;     % your condition
 if cond
     C = [A;B];    % concatanate A and B
 end