How to remove duplicate observations in a matrix after sorting it?

I have a matrix FINAL=[1001,4,5,2015;1002,4,5,2015;1001,4,10,2014;1003,4,10,2014]

I want to sort this matrix by col 1, col 4, col 2, col 3 (i.e. organize column 1 by date)

Then I want to keep only the first row of a unique value of column 1

Any advice?

Answer 1

[Jos (10584)]

FINAL=[1001,4,5,2015;1002,4,5,2015;1001,4,10,2014;1003,4,10,2014]
X = sortrows(FINAL,[1 4 2 3]) % not sure what you want here ...
[~,i] = unique(X(:,1)) 
OUT = X(i,:)