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authorMatt Strapp <strap012@umn.edu>2021-04-26 17:12:01 -0500
committerMatt Strapp <strap012@umn.edu>2021-04-26 17:12:01 -0500
commita093060b0e8a787e51212b5f2879dc839605da65 (patch)
tree7ec2d69219d41ae6447efc41ebaaac34c696984b /dotsandboxes/agents/algorithms/ann.py
parentRefactor jsut about everything (diff)
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Revert "Refactor jsut about everything"
This reverts commit e58a60ed18bde5db28ba96910df518a61b3999b2.
Diffstat (limited to 'dotsandboxes/agents/algorithms/ann.py')
-rw-r--r--dotsandboxes/agents/algorithms/ann.py170
1 files changed, 0 insertions, 170 deletions
diff --git a/dotsandboxes/agents/algorithms/ann.py b/dotsandboxes/agents/algorithms/ann.py
deleted file mode 100644
index 05ae647..0000000
--- a/dotsandboxes/agents/algorithms/ann.py
+++ /dev/null
@@ -1,170 +0,0 @@
-from numpy import *
-from math import sqrt
-from copy import deepcopy
-from time import time
-
-class ANN:
-
- """ANN with one hidden layer, one output and full connections in between consecutive layers.
- Initial weights are chosen from a normal distribution.
- Activation function is tanh."""
-
- INIT_SIGMA = 0.02
- REL_STOP_MARGIN = 0.01
- MAX_ITERATIONS = 1000000
- ACTIVATION = tanh
- D_ACTIVATION = lambda x: 1 - tanh(x)**2 # Derivative of tanh
- VEC_ACTIVATION = vectorize(ACTIVATION)
- VEC_D_ACTIVATION = vectorize(D_ACTIVATION)
- STEP_SIZE = 0.1
-
- def __init__(self, input_size, hidden_size):
-
- #self.input_size = input_size
- #self.hidden_size = hidden_size
- self.hidden_weights = random.normal(0, ANN.INIT_SIGMA, (hidden_size, input_size))
- self.output_weights = random.normal(0, ANN.INIT_SIGMA, hidden_size)
-
- def get_weights(self):
- return self.hidden_weights, self.output_weights
-
- def predict(self, input_vector):
-
- # Predicts the output for this input vector
- # input_vector will be normalized
-
- input_vector = input_vector/linalg.norm(input_vector)
- return ANN.ACTIVATION(dot(self.output_weights, ANN.VEC_ACTIVATION(dot(self.hidden_weights, input_vector))))
-
- @staticmethod
- def frob_norm(a, b):
-
- # Calculates the total Frobenius norm of both matrices A and B
- return sqrt(linalg.norm(a)**2 + linalg.norm(b)**2)
-
- def train(self, examples):
-
- #print("Training")
- start = time()
-
- # examples is a list of (input, output)-tuples
- # input will be normalized
- # We stop when the weights have converged within some relative margin
-
- for example in examples:
- example[0] = example[0]/linalg.norm(example[0])
-
- iteration = 0
- while True:
-
-
- # Store old weights to check for convergence later
- prev_hidden_weights = deepcopy(self.hidden_weights)
- prev_output_weights = deepcopy(self.output_weights)
-
- for k in range(len(examples)):
-
- input_vector, output = examples[k]
-
- # Calculate outputs
- hidden_input = dot(self.hidden_weights, input_vector)
- hidden_output = ANN.VEC_ACTIVATION(hidden_input)
- final_input = dot(self.output_weights, hidden_output)
- predicted_output = ANN.ACTIVATION(final_input)
-
- #print("Output:", output)
- #print("Predicted output:", predicted_output)
-
- # Used in calculations
- prediction_error = output - predicted_output
- output_derivative = ANN.D_ACTIVATION(final_input)
-
- # Adjust output weights and calculate requested hidden change
- requested_hidden_change = prediction_error*output_derivative*self.output_weights
- self.output_weights = self.output_weights + ANN.STEP_SIZE*prediction_error*hidden_output
-
- #print("After adjusting output weights:", ANN.ACTIVATION(dot(self.output_weights, hidden_output)))
-
- # Backpropagate requested hidden change to adjust hidden weights
- self.hidden_weights = self.hidden_weights + ANN.STEP_SIZE*outer(requested_hidden_change*(ANN.VEC_D_ACTIVATION(hidden_input)), input_vector)
-
- #print("After adjusting hidden weights:", ANN.ACTIVATION(dot(self.output_weights, ANN.VEC_ACTIVATION(dot(self.hidden_weights, input_vector)))))
-
- # Check stop criteria
- iteration += 1
- if iteration >= ANN.MAX_ITERATIONS:
- break
-
- # Check stop criteria
- if iteration >= ANN.MAX_ITERATIONS:
- break
- diff = ANN.frob_norm(self.hidden_weights - prev_hidden_weights, self.output_weights - prev_output_weights)
- base = ANN.frob_norm(self.hidden_weights, self.output_weights)
- #if base > 0 and diff/base < ANN.REL_STOP_MARGIN:
- # break
-
- print(time() - start)
- print("Stopped training after %s iterations."%iteration)
-
-# TESTING
-
-def print_difference(ann1, ann2):
-
- # Prints the differences in weights in between two ANN's with identical topology
-
- hidden_weights1, output_weights1 = ann1.get_weights()
- hidden_weights2, output_weights2 = ann2.get_weights()
- hidden_diff = hidden_weights1 - hidden_weights2
- output_diff = output_weights1 - output_weights2
-
- print(hidden_diff)
- print(output_diff)
- print("Frobenius norms:")
- print("Hidden weights difference:", linalg.norm(hidden_diff))
- print("Output weights difference:", linalg.norm(output_diff))
- print("Both:", ANN.frob_norm(hidden_diff, output_diff))
-
-def RMSE(ann, examples):
-
- total = 0
- for input_vector, output in examples:
- total += (output - ann.predict(input_vector))**2
- return sqrt(total/len(examples))
-
-def generate_examples(amount, input_size, evaluate):
- # evaluate is a function mapping an input vector onto a numerical value
- examples = []
- inputs = random.normal(0, 100, (amount, input_size))
- for i in range(amount):
- input_vector = inputs[i]
- examples.append([input_vector, evaluate(input_vector)])
- return examples
-
-def test():
-
- # Test the ANN by having it model another ANN with identical topology but unknown weights
-
- input_size = 5
- hidden_size = 3
- real = ANN(input_size, hidden_size)
- model = ANN(input_size, hidden_size)
-
- # Generate training data
- training_data = generate_examples(10000, input_size, real.predict)
- validation_data = generate_examples(10000, input_size, real.predict)
-
- # Print initial difference, train, then print new difference
- print("Initial difference:")
- print_difference(real, model)
- print("Initial RMSE (on training data):", RMSE(model, training_data))
- print("Initial RMSE (on validation data):", RMSE(model, validation_data))
- model.train(training_data)
- print("After training:")
- print_difference(real, model)
- print("After training RMSE (on training data):", RMSE(model, training_data))
- print("After training RMSE (on validation data):", RMSE(model, validation_data))
-
-if __name__ == "__main__":
- test()
-
-