MATLAB: Assigning values from one array to another if certain specifications are met.

arraycantileverMATLABmatrix

I have a few arrays
A=   0     1     2     3     6     8     9    10
     0     0     0     0     0     0     0     0
     0     0     0     0     0     0     0     0
     
B=  20     5    15    10
     9     8     2     1
     
C=  10    15
     9     3
Bassically the first row of A contains special points from a line that goes from 0 to 10 and the other two rows are where the values from B( to second row) and C( to third row) should go. Second rows of B and C are corresponding points from the first row of A.
For example. Since B(2,1)=A(1,7) then B(1,1) should go to A(2,7) like this:
A=   0     1     2     3     6     8     9    10
     0     0     0     0     0     0    20     0
     0     0     0     0     0     0     0     0
The final result should look like this:
A=   0     1     2     3     6     8     9    10
     0    10    15     0     0     5    20     0
     0     0     0    15     0     0    10     0
I am very much still a beginner in Matlab. I am writing a script that would calculate shear forces and bending moments of a cantilever beam so any advice and/or suggestions would be greatly appreciated.

Best Answer

Inputs:
A=  [ 0     1     2     3     6     8     9    10
    0     0     0     0     0     0     0     0
    0     0     0     0     0     0     0     0];
B= [ 20     5    15    10
    9     8     2     1];
C=  [10    15
    9     3];
Solution:
[isMatch, col] = ismember(B(2,:), A(1,:));
A(2,col(isMatch)) = B(1,isMatch);
[isMatch, col] = ismember(C(2,:), A(1,:));
A(3,col(isMatch)) = C(1,isMatch);
Result:
>> A
A =
     0     1     2     3     6     8     9    10
     0    10    15     0     0     5    20     0
     0     0     0    15     0     0    10     0
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