level: Level 1
Questions and Answers List
level questions: Level 1
| Question | Answer |
|---|---|
| Projection Matrix | Given by |
| m x n | rows by columns |
| lower triangular | values at bottom |
| upper triangular | values at top |
| matrix not square for best fit? | try timsing by AT |
| inverse equal to transpose | when orthogonal AND unit vectors - (then matrix is just a rotation) |
| probability of a variable being between 2 values | integrate prob density function, f(x) between 2 values |
| variance of standard gaussian | equals 1 and is |