Homework 4 (due Thursday, September 16th)

1. Suppose the vectors in the set E = {v1, v2, ..., vm} span an n-dimensional vector space V (and so necessarily nm). Let
c : ER
be a cost function on E. Show that the following algorithm finds a basis BE for V of least total cost c(B) := ∑e &isin B c(e).

  1. Let B0 = ∅
  2. Given Bi, i < n, choose xi+1E \ Bi such that
    i. Bi+1 := Bi ∪ {xi+1} is linearly independant, and
    ii. xi+1 is the cheapest such element of E \ Bi.
  3. Let B = Bn.

2. 3B

3. 3G

4. 3I