MATLAB: What does the ‘i’ mean in [y,i] = unique(A)

MATLABmatrixvector index

If I got a m x 1 matrix and I perform this little piece of code in Matlab it returns two arrays 'y' and 'i', where 'y' holds the unique numbers en 'i' holds the row numbers of the unique numbers? I don't understand why this is. Can someone explain this to me?

Best Answer

  • It’s the index into ‘A’, so that ‘y=A(i)’. It returns the index of the first instance of the unique values. If you want all of them (indirectly), you have to ask for the third argument as well.