COSC 420/427/527 Project 3 — Hopfield Net

Due March 23, 2020

General Description

For COSC 420 Credit

  1. Generate 50 random bipolar vectors (N = 100).
  2. For p = 1, ..., 50, imprint the first p patterns on a Hopfield net.  (The rule for imprinting p patterns is given on slide 63 in Part 3A.)
  3. Determine pstable, the number of stable imprinted patterns.  An imprinted pattern is considered unstable if any of its bits are unstable, that is, if bit i is of opposite sign to its local field hi.  Therefore, after imprinting the first p patterns, test each imprinted pattern k (k = 1, …, p) as follows: Initialize the cells to pattern k and compute the local fields hi of each bit. Compare each bit with local field to test for stability.  Repeat for each of the p patterns.   (The computation of the local field is described on slides 5–6 in Part 3A.)
  4. Compute the probability of an imprinted pattern being stable, Pstable = pstable / p.  (Note that p, Pstable, and pstable are different; this is Bar-Yam’s notation, which I’ve retained for consistency with his book.)
  5. Repeat steps 2–4 for p = 1, ..., 50 and keep track of Pstable for each value of p.
  6. Repeat the forgoing for several sets of 50 random patterns and average over them.

For COSC 427 and 527 Credit

If you have any other questions, please post them on Piazza.

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Last updated: 2020-02-25.