Psychology 149
Machine Learning & AI


Lab Project 3:



1)  Use Matlab functions to create the neural network shown in the image below:

 

Then change the activation functions of the hidden layers from the default tangent to the sigmoidal logistic (logsig) function.  Also change the activation function of the output layer from the default 'pure linear' to the tangent function (tansig).  
Set the learning rule to gradient descent (traingd)
Set the learning rate to 0.2

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2) Write a program that  can determine which of 3 wineries a sample of wine has come from.  Matlab has created a number of datasets that can be used for training a variety of networks.  One of these datasets can be used for this project.  The data set is called "wine_dataset" which contains two variables. To load the data set, type the following:

clear all;
load wine_dataset;

Then type "who" in the command window and hit return to see what the variable names are.  

The two variable names are
"wineInputs"   and "wineTargets"



                            
The problem to solve is this:  There are 178 sample bottles of wine.  Each of these wines comes from one of three wineries (lets say Sonoma in Northern California, Bordeaux in France, and a local winery in Newport Beach).  

We will use the two variable to train the network: "wineInputs" provides the raw training data and "wineTargets" provides the "correct answers" used to train the network in supervised learning.  Note that both "wineInputs" and "wineTargets" have the same number of columns (178) because there are 178 samples of wine.

The "wineInputs" variable is a 13x178 matrix.  This is because there are 178 sample wines (each column corresponds to one of the 178 sample wines) and there are 13 rows. Each row corresponds to one aspect or feature of the wine (for example,  color intensity, hue, ash, acidity, alcohol content, ...).  So to train the network, differences in these 13 features across the 178 samples are used to try to distinguish between the wines from the 3  wineries.  

For this project, just use the Matlab default settings for creating and training the network.  This is actually a relatively easy problem to solve.


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