Merge two files with different information

I have two .txt files and I would like to combine the two and put them in one. My files looks like this:

file1.txt

1998 1 1 32.5 
1998 1 2 37.2 
1998 1 3 40.4 
1998 1 5 30.8 

file2.txt

1998 1 1 28.2 
1998 1 2 35.2
1998 1 4 39.6 
1998 1 6 33.0 

So, I need an output like this:

1998 1 1 32.5 28.2 
1998 1 2 37.2 35.2 
1998 1 3 40.4 - 
1998 1 4   -  39.6 
1998 1 5 30.8 -
1998 1 6    - 33.0 

or

1998 1 1 32.5 28.2 
1998 1 2 37.2 35.2 
1998 1 3 40.4 
1998 1 4 39.6 
1998 1 5 30.8 
1998 1 6      33.0

or

1998 1 1 32.5 28.2 
1998 1 2 37.2 35.2 
1998 1 3 40.4 NaN 
1998 1 4 NaN  39.6 
1998 1 5 30.8 NaN 
1998 1 6 NaN  33.0 

After obtaining this output, remove as lines that do not contain information in the last two columns. Can anybody help me?

[Walter Roberson]

I suggest you put the information into a table() object and use innerjoin()

Answer 1

[Akira Agata]

As Walter-san mentioned, the solution would be like this:

% Read .txt files
T1 = readtable('file1.txt','ReadVariableNames',false);
T2 = readtable('file2.txt','ReadVariableNames',false);

% Merge T1 and T2 using innerjoin function
Tall = innerjoin(T1,T2,'Keys',[1 2 3]);