Adding duplicate values based on table variable names

I have a large set of tables, separated by date, with geographical coordinates (X_LOC and Y_LOC) and user defined fields to visualize ('CustInt', for example).

My mission is to combine those tables, and if exact X_LOC and Y_LOC duplicates exist, add the values together. Though, this may not be a necessity as the precision of the coordinates is in the 0.000001 range. So for example:

File 1:                                              File 2:
X_LOC    Y_LOC    CustInt  {... other fields}        X_LOC    Y_LOC    CustInt
12.100   13.100    20             ...                12.100   13.11    20

Combined:
X_LOC    Y_LOC    CustInt
12.100   13.100   20
12.100   13.11    20

The only thing to keep in mind is that the files are large (thousands * 31 variables) and my idea of iterating through duplicates could increase complexity exponentionally.

Would a simple outerjoin() be helpful? Is there any way of combining only columns that you want for two tables?

Thanks in advance.

[BN]

In my opinion using the "ismember" function mybe helpful to determine the matching rows in file1 and file2 and adding the missing entries.

[file1, file2] = ismember(file1.X_LOC, file2.X_LOC);
file1(indx1,'X_LOC') = file2(indx2(indx1),'X_LOC');

Then you can remove unwanted columns.

[Stephen23]

@Behzad Navidi: your code overwrites file1 and file2, and does not define indx1 nor indx2. Did you mean?:

[indx1, indx2] = ismember(file1.X_LOC, file2.X_LOC);

[BN]

Oh, I'm sorry my bad. Yes, I thought he could think about ismember. Thank you.

[Walter Roberson]

ismembertol seems more realistic than ismember for this purpose