Collection of my machine-learning stuff.
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import numpy as np
class AIlib:
def sigmoid(x):
return 1/(1 + np.exp(-x))
def correctFunc(inp:np.array): # generates the correct answer for the AI
return np.array( [inp[2], inp[1], inp[0]] ) # basically invert the rgb values
def calcCost( predicted:np.array, correct:np.array ): # cost function, lower -> good, higher -> bad, bad bot, bad
return (predicted - correct)**2
def getThinkCost( inp:np.array, predicted:np.array ):
corr = correctFunc(inp)
return calcCost( predicted, corr )
def genRandomMatrix( x:int, y:int, min: float=0.0, max: float=1.0 ): # generate a matrix with x, y dimensions with random values from min-max in it
# apply ranger with * and -
mat = np.random.rand(x, y) - 0.25
return mat
def think( inp:np.array, obj, layerIndex: int=0 ): # recursive thinking, hehe
maxLayer = len(obj.weights) - 1
weightedLayer = np.dot( inp, obj.weights[layerIndex] ) # dot multiply the input and the weights
layer = AIlib.sigmoid( np.add(weightedLayer, obj.bias[layerIndex]) ) # add the biases
if( layerIndex < maxLayer ):
return AIlib.think( layer, obj, layerIndex + 1 )
else:
out = np.squeeze(np.asarray(layer))
return out
def propDer( dCost, dProp ):
# Calculate the partial derivative for that prop
return dCost / dProp
def gradient( inp:np.array, obj, theta:float, maxLayer:int, layerIndex: int=0, grads: list=[], obj1=None, obj2=None ):
# Calculate the gradient for that prop
# Create new instances of the object
if( !obj1 or !obj2 ):
obj1 = obj
obj2 = obj
obj2.weights[layerIndex] += theta # mutate the second object
obj2.bias[layerIndex] += theta
# Compare the two instances
res1 = AIlib.think( inp, obj1 )
cost1 = AIlib.getThinkCost( inp, res1 ) # get the cost
res2 = AIlib.think( inp, obj2 )
cost2 = AIlib.getThinkCost( inp, res2 ) # get the second cost
# Actually calculate stuff
dCost = cost2 - cost1
dWeight = obj2.weights[layerIndex] - obj1.weights[layerIndex]
dBias = obj2.bias[layerIndex] - obj1.bias[layerIndex]
# Calculate the gradient for the layer
weightDer = AIlib.propDer( dCost, dWeight )
biasDer = AIlib.propDer( dCost, dBias )
# Append the gradients to the list
grads[layerIndex] = {
"weight": weightDer,
"bias": biasDer
}
newLayer = layerIndex + 1
if( newLayer <= maxLayer ):
return AIlib.gradient( inp, obj, theta, maxLayer, newLayer, grads, obj1, obj2 )
else:
return grads
def mutateProp( prop:list, lr:float, gradient ):
newProp = [None] * len(prop)
for i in range(len(prop)):
newProp[i] = prop[i] - (lr*gradient)
return newProp
def learn( inp:np.array, obj, theta:float ):
# Calculate the derivative for:
# Cost in respect to weights
# Cost in respect to biases
# i.e. : W' = W - lr * gradient (respect to W in layer i) = W - lr*[ dC / dW[i] ... ]
# So if we change all the weights with i.e. 0.01 = theta, then we can derive the gradient with math and stuff