In my text, it tells me to find the eigenvectors of a 2nd difference matrix and graph the eigenvectors to see how they fall onto sine curves. imgur link: http://i.imgur.com/oxbkTn6.jpg My question is simple but general. What does this even mean? How did they produce this graph from the first two eigenvectors in the matrix on the left? I tried in matlab to create an outer product of each vector with a time vector, but that plots straight lines.