Quiz7

1.

Which one of the following is not LDA?

Answer

  • ☐ \(\max \frac{|m_1 - m_2|}{s_1^2 + s_2^2}\)
  • ☐ \(\min \frac{s_1^2 + s_2^2}{(m_1 - m_2) . (m_1 - m_2)}\)
  • ☑ \(\min \frac{|m_1 - m_2|}{s_1^2 + s_2^2}\)
  • ☐ \(\max \frac{|m_2 - m_1|}{s_1^2 + s_2^2}\)

Question 2

A dataset lies in d dimensions. Which one of the following is true (Choose best option)?

Answer

  • ☐ PCA and LDA project data to 1 < d' <= d dimensions
  • ☐ PCA projects data to 1 dimension, LDA projects data to 1 < d' <=d dimensions
  • ☑ PCA projects data to d' <= d and LDA projects data to 1 dimension
  • ☐ PCA and LDA project data to 1 dimension

Question 3

Which of the following is true?

Answer

  • ☐ LDA inputs data only. PCA inputs data and labels
  • ☑ LDA inputs dataset and label. PCA inputs only dataset
  • ☐ Both PCA & LDA input dataset only
  • ☐ Both PCA & LDA input dataset and labels

Question 4

A dataset lies in d dimensions. Which of the following is true of PCA & LDA?

Answer

  • ☐ Both methods project data to higher dimension
  • ☑ Both methods project data to lower dimension
  • ☐ Both maximize variance in ℝd
  • ☐ Both minimize variance in ℝd

Question 5

Which of the following is a generalized eigenvector problem?

Answer

  • ☐ \(Ax = \lambda x\)
  • ☐ \(Ax = A^{-1}x\)
  • ☑ \(Ax = \lambda B x\)
  • ☐ \(Ax = x\)