The vector * What is a vector? ** Vectors are functions ** Representation of vectors using Python dictionaries *** Sparsity ** What can we represent with a vector? * Vector addition ** Vector addition: The zero vector ** Vector addition: Vector addition is associative and commutative ** Vector addition: Vectors as arrows * Scalar-vector multiplication ** Scalar-vector multiplication: Scaling arrows ** Scalar-vector multiplication: Associativity of scalar-vector multiplication ** Scalar-vector multiplication: Line segments through the origin ** Scalar-vector multiplication: Lines through the origin * Combining vector addition and scalar multiplication ** Combining vector addition and scalar multiplication: Distributive laws ** Combining vector addition and scalar multiplication: First look at convex combinations ** Combining vector addition and scalar multiplication: First look at affine combinations * Vectors over GF(2) ** Vectors over GF(2): Perfect secrecy ** Vectors over GF(2): All-or-nothing secret-sharing using GF(2) ** Vectors over GF(2): Lights Out * Dot-product ** Dot-product: Total cost or benefit ** Dot-product: Linear equations ** Dot-product: Measuring similarity: Comparing voting records ** Dot-product: Vectors over GF(2) *** Dot-product: Simple authentication scheme *** Dot-product: Attacking simple authentication scheme * Dictionary-based representations of vectors ** Dictionary-based representations of vectors: Setter and getter ** Vec class ** Using Vec *** Assertions in Vec *** Testing Vec with doctests *** list2vec *** The vecutil module * Solving a triangular system of linear equations ** Solving a triangular system of linear equations: Backward substitution * %%% Local Variables: %%% mode: org %%% eval: (auto-fill-mode t) %%% eval: (flyspell-mode t) %%% End: