how to append matrix value from lookup list

I have the following matrix A =

           0        34.5          10           3      22.753      8.9632
           0        34.5          10           7      22.753      8.9632
           0        68.9          10           3      22.753      8.9632
           0        68.9          10           7      22.753      8.9632
           0       137.9          10           3      22.753      8.9632
           0       137.9          10           7      22.753      8.9632
           0       206.8          10           3      22.753      8.9632
           0       206.8          10           7      22.753      8.9632
           0       275.8          10           3      22.753      8.9632
           0       275.8          10           7      22.753      8.9632
          10        34.5          10           3      22.753      8.9632
          10        34.5          10           7      22.753      8.9632
          10        68.9          10           3      22.753      8.9632
          10        68.9          10           7      22.753      8.9632
          10       137.9          10           3      22.753      8.9632
          10       137.9          10           7      22.753      8.9632
          10       206.8          10           3      22.753      8.9632
          10       206.8          10           7      22.753      8.9632
          10       275.8          10           3      22.753      8.9632
          10       275.8          10           7      22.753      8.9632

I want to insert a new column to the right containing values from the following lookup list

B =

           0        34.5       328.5
           0        68.9       415.6
           0       137.9       589.6
           0       206.8       727.9
           0       275.8       856.1
          10        34.5       307.4
          10        68.9         362
          10       137.9       541.6
          10       206.8       695.6
          10       275.8       856.1
          20        34.5       263.9
          20        68.9       337.5
          20       137.9       503.8
          20       206.8       635.3
          20       275.8         749
          30        34.5       224.9
          30        68.9       297.4
          30       137.9       437.9
          30       206.8       573.9
          30       275.8       673.1

The values in the new columns in A is based on the lookup list of B.

Manually, I would expect something like this

C =

           0        34.5          10           3      22.753      8.9632   328.5
           0        34.5          10           7      22.753      8.9632   328.5
           0        68.9          10           3      22.753      8.9632   415.6
           0        68.9          10           7      22.753      8.9632   415.6
           0       137.9          10           3      22.753      8.9632   589.6
           0       137.9          10           7      22.753      8.9632   589.6
           0       206.8          10           3      22.753      8.9632   727.9
           0       206.8          10           7      22.753      8.9632   727.9
           etc...

Notice the last column of C is based on the values in A column 1 and 2 which is matched with the lookup list in B column 1 and 2.

Can anyone help me.

[Jan]

So actually only the 2 first columns of A matter, right? How is the lookup table used: choose the nearest 2 elements, choose at exact match (what is dangerous for floating point values), linear interpolation? What should happen to the elements, which are not found in B?

[BeeTiaw]

Hi Simon,

Correct. in each row, the first two columns of A has to be exactly match with the first two columns in B.

If the condition satisfies, the value will be taken from the third column of B.

Answer 1

[Jan]

Perhaps:

[LiA, LocB] = ismember(A(:, 1:2), B(:, 1:2), 'rows');
C           = [A, B(LocB, 3)]

Use ismembertol to consider numerical rounding errors.

[BeeTiaw]

Thanks you! This is exactly what I expect.

appreciate your time.