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pythonmachine-learningrandom-forestfeature-extraction

how to control the number of features [machine learning]?


I am writing this machine learning code (classification) to clssify between two classes. I started by having one feature to capture for all my images.

for example: (note: 1 & 0 are for labeling) class A=[(4295046.0, 1), (4998220.0, 1), (4565017.0, 1), (4078291.0, 1), (4350411.0, 1), (4434050.0, 1), (4201831.0, 1), (4203570.0, 1), (4197025.0, 1), (4110781.0, 1), (4080568.0, 1), (4276499.0, 1), (4363551.0, 1), (4241573.0, 1), (4455070.0, 1), (5682823.0, 1), (5572122.0, 1), (5382890.0, 1), (5217487.0, 1), (4714908.0, 1), (4697137.0, 1), (4057898.0, 1), (4143981.0, 1), (3899129.0, 1), (3830584.0, 1), (3557377.0, 1), (3125518.0, 1), (3197039.0, 1), (3109404.0, 1), (3024219.0, 1), (3066759.0, 1), (2726363.0, 1), (3507626.0, 1), .....etc]

class B=[(7179088.0, 0), (7144249.0, 0), (6806806.0, 0), (5080876.0, 0), (5170390.0, 0), (5694876.0, 0), (6210510.0, 0), (5376014.0, 0), (6472171.0, 0), (7112956.0, 0), (7356507.0, 0), (9180030.0, 0), (9183460.0, 0), (9212517.0, 0), (9055663.0, 0), (9053709.0, 0), (9103067.0, 0), (8889903.0, 0), (8328604.0, 0), (8475442.0, 0), (8499221.0, 0), (8752169.0, 0), (8779133.0, 0), (8756789.0, 0), (8990732.0, 0), (9027381.0, 0), (9090035.0, 0), (9343846.0, 0), (9518609.0, 0), (9435149.0, 0), (9365842.0, 0), (9395256.0, 0), (4381880.0, 0), (4749338.0, 0), (5296143.0, 0), (5478942.0, 0), (5610865.0, 0), (5514997.0, 0), (5381010.0, 0), (5090416.0, 0), (4663958.0, 0), (4804526.0, 0), (4743107.0, 0), (4898914.0, 0), (5018503.0, 0), (5778240.0, 0), (5741893.0, 0), (4632926.0, 0), (5208486.0, 0), (5633403.0, 0), (5699410.0, 0), (5748260.0, 0), (5869260.0, 0), ....etc]

/data is A and B combined

x = [[each[0]] for each in data]
y = [[each[1]] for each in data]
print (len(x), len(y))

x_train, x_test, y_train, y_test = train_test_split(x, y, test_size=0.2, 
random_state=42)
print (len(x_train), len(x_test))
print (len(y_train), len(y_test))

from sklearn.ensemble import RandomForestClassifier

clf = RandomForestClassifier(n_estimators=100, max_depth=2, random_state=0)
clf.fit(x_train, y_train)

Question:

what to change to add another feature? how the A and B should look when adding the feature and do I change this line

clf = RandomForestClassifier(n_estimators=100, max_depth=2, random_state=0)

when using two features?

My guess:

class A=[(4295046.0,secons features, 1), (4998220.0,secons features, 1), (4565017.0,secons features, 1), (4078291.0,secons features, 1), (4350411.0,secons features, 1), (4434050.0, 1),......] is that right? is there better way?


Solution

  • This model doesn't need explicitly the number of features.
    If the class is always the last element in each tuple in the data, you can do:

    x = [[each[:-1]] for each in data]
    y = [[each[-1]] for each in data]
    

    And just carry on the same from there.