How to add two tables

I have two tables of different number of rows but with same structure. They both have 3 columns, the 3rd column is numbers. How to create a new table which has the common rows on column 1 and column2 and sum on column 3?

Thanks.

Jennifer

Answer 1

[Kirby Fears]

Hi Jennifer,

Here's code with sample data that performs your task.

 data=magic(3); % sample data
 % creating sample tables 1 and 2
 table1=array2table(data,'VariableNames',{'key1','key2','values'});
 table2=array2table(data,'VariableNames',{'key1','key2','values'});

 % joining tables on key1 and key2 only
 tablejoin=join(table1,table2,'Keys',{'key1','key2'});

 % add value columns together and delete the extra column
 tablejoin.values_table1=tablejoin.values_table1+tablejoin.values_table2;
 tablejoin.values_table2=[];

Hope this helps.

[JFz]

Thanks so much! It works! Works exactly as I wished. The only thing is that, what is the two tables are not of the same number of rows? Say, one table has 4 rows, the other only 3 rows.

[JFz]

Hi, Kirby,

I got an error:

Error using table/join (line 132) The key variables for B must contain all unique combinations of values in the key variables for A.

[JFz]

I tried to use 'Type' in the join, but I keep getting this error: Error using table/join (line 85) Invalid parameter name: Type.

[JFz]

I tried to use innerjoin but I got 0 row in the resulting table.

[JFz]

Hi,

Thanks Kirby,

I got it! I used innerjoin on two table and it worked!