Table Assignment using two tables of different height.

I have two tables of different heights: table1 and table2.

Both tables have the field x and table2 also has the field y.

I want to assign to table1 the parameter y where the table1 x parameter is equal to the table2 x parameter.

Since the tables are big It would be too inefficient of me to try and do double for loops I believe. Can someone help me with an efficient code to do that?

To be more informative, I'd like to do:

table1(table1.x == table2.x).y = table2.y

But since the two tables are not in the same height I can't do that.

Answer 1

[Stephen23]

You can use ISMEMBER like this:

T1 = array2table([8,5;9,9;2,9;9,2;6,9;1,9;3,5])

T1 = 7×2 table
    Var1    Var2
    ____    ____

     8       5  
     9       9  
     2       9  
     9       2  
     6       9  
     1       9  
     3       5  

T2 = array2table([6,0;7,0.1;8,0.2;9,0.3])

T2 = 4×2 table
    Var1    Var2
    ____    ____

     6        0 
     7      0.1 
     8      0.2 
     9      0.3 

[X,Y] = ismember(T1.Var1,T2.Var1);
T1.Var2(X) = T2.Var2(Y(X))

T1 = 7×2 table
    Var1    Var2
    ____    ____

     8      0.2 
     9      0.3 
     2        9 
     9      0.3 
     6        0 
     1        9 
     3        5 

[kuku hello]

thank you very much! It works perfectly!

Answer 2

[Adam Danz]

There are several ways to join tables.

• join
• innerjoin
• outerjoin

If you get stuck, provide an example of the two tables and the expected result after joining the tables, and show what you've tried so we can help out.

[kuku hello]

Thanks I wasn't aware of those functions, and yet the variable x is not equal in both tables.

Meaning some x variables in table 1 exist and in table 2 they don't and vice versa. I see that join ain't what I'm looking for and the innerjoin deletes the rows that are not in common. outerjoin would duplicate rows with the same x since in table2 x values repeat themselves.