Beer Stock Exchange


Abusing the Sigmoid Function for fun and profit

We need to modify our sigmoid function so that we can control its min and max.

Description of the algorithm

Start with your list of beers [b1,b2,b3,b4,b5].At the beginning of the night the price for all beers is its base price (x=0) [0,0,0,0,0]. At the end of each trading period, count the number of beers sold in the time period [135, 152, 65, 103, 201]. Find the average number sold per beer (131.2) and find the difference between average and actual number sold for each beer [3.8, 20.8, -66.2, -28.2, 69.8]. Normalize this against your c by dividing by a (139.6) to get [0.03, 0.15, -0.47, -0.20, 0.5]. This becomes the change between the old x and the new x for each beer. If you never round, the average x will always be 0, however this is not feasible so you may want to normalize x every few rounds to make sure your average x stays 0.