Similarity between two data sets or arrays
Let's say I have a dataset that look like this: {A:1, B:3, C:6, D:6} I also have a list of other sets to compare my specific set: {A:1, B:3, C:6, D:6}, {A:2, B:3, C:6, D:6}, {A:99, B:3, C:6, D:6}, {A:5, B:1, C:6, D:9}, {A:4, B:2, C:2, D:6} My entries could be visualized as a Table (with four columns, A, B, C, D, and E). How can I find the set with the most similarity? For this example, row 1 is a perfect match and row 2 is a close second, while row 3 is quite far away. I am thinking of calculating a simple delta, for example: Abs(a1 - a2) + Abs(b1 - b2) + etc and perhaps get a correlation