MATLAB: Inner Joining

[kristin2014]

Anyone familiar with MATLAB's function of 'inner joining'? I need to take two files, with four columns of data, and 'inner join' them.

[Hung Kieu]

I posted your question in our discussion group. HOpefully you can get some help from there as well! www.facebook.com/groups/594511053910398/permalink/616640808364089/

[Wirespeed]

Check out the link below. I'm not terribly familiar with the concept of an 'inner join' but hopefully this helps. If not, then I recognize 'inner join' as an SQL term and I have a friend or 2 who is a fair bit more experienced with SQL than I am - I'll see if I can't get some guidance from them.

www.mathworks.com/help/stats/dataset.join.html



Anyway, near as I can tell, you'll want to use the command

C = join(A,B,'Type',inner) - You can use the MATLAB load command to actually load the files into A and B matricies, of course.

From the linked article: 

For an inner join, C only contains observations corresponding to a combination of key values that occurred in both A and B. For a left (or right) outer join, C also contains observations corresponding to keys in A (or B) that did not match any in B (or A). Variables in C taken from A (or B) contain null values in those observations. A full outer join is equivalent to a left and right outer join. C contains variables corresponding to the key variables from both A and B, and join sorts the observations in C by the key values.

[joaodsemeano]

What does "inner joining" data sets mean?? What's the objective of such an operation?

[Hellfire]

Inner joining data sets is a way to combine data. Joining creates a new result when it combines values from two seperate tables. End result is a new table.