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python-3.xtensorflowartificial-intelligenceregressionnon-linear-regression

TensorFlow : polynomial regression


I am trying to get a non-linear regression from a CSV data which is available at this link: CSV Data

I want to use polynomial regression. the problem is that the result I am getting from TensorFlow is "None". I cannot find the problem. I think there is something wrong with the model or the cost function. can anybody help? any help would be appreciated.

# importing modules
import tensorflow as tf
import numpy as np
import matplotlib.pyplot as plt
import csv
import time

# defining the method for gathering data
# date_idx is the column number of date in the .CSV file
def read(filename, date_idx, date_parse, year, bucket=7):

    # the amount of days in the year : 365 days
    days_in_year = 365

    # defining a dictionary for the frequency
    freq = {}
    # here we are calculating hao many buckets each frequency have?
    # buckets = (which is 7, and by that we mean each frequency is 7 days)
    # we are initializing each frequency with zero
    for period in range(0, int(days_in_year / bucket)):
        freq[period] = 0

    # this opens the file in binary mode('rb' : 'r' for read, 'b' is for binary mode)
    with open(filename, 'r') as csvfile:
        csvreader = csv.reader(csvfile)
        next(csvreader)                   # this escapes the first row since it consists of headers only
        for row in csvreader:
            if row[date_idx] == '':        # each row consists of many columns but if the date is
                continue                   # is unavailable there is no need to check the data
            t = time.strptime(row[date_idx], date_parse)    # converting to the input format
            if t.tm_year == year and t.tm_yday < (days_in_year-1):  # we want the data in specific year
                freq[int(t.tm_yday / bucket)] += 1          # finding the frequency
    return freq

# here i call the method to gather data for me
freq = read(r'C:\My Files\Programming\Python\TensorFlow\CallCenter\311_Call_Center_Tracking_Data__Archived_.csv',
            0, '%m/%d/%Y', 2014)

# here we convert our dictionary into 2 arrays or lists in python
x_temp =[]
y_temp =[]
for key, value in freq.items():
    x_temp.append(key)
    y_temp.append(value)

x_data = np.asarray(x_temp)
y_data = np.asarray(y_temp)

# visualizing the data
plt.scatter(x_data,y_data)
plt.show()

# splitting data with ratio into 2 group : training and test
def split_dataset(x_dataset, y_dataset, ratio):
    arr = np.arange(x_dataset.size)
    np.random.shuffle(arr)
    num_train = int(ratio*x_dataset.size)
    x_train = x_dataset[arr[0:num_train]]
    y_train = y_dataset[arr[0:num_train]]
    x_test = x_dataset[arr[num_train:x_dataset.size]]
    y_test = y_dataset[arr[num_train:y_dataset.size]]
    return x_train,y_train,x_test,y_test

x_train, y_train, x_test, y_test = split_dataset(x_data,y_data, ratio=0.7)

# here we create some place holder for input and output of the session
X = tf.placeholder(tf.float32)
Y = tf.placeholder(tf.float32)

# defining global variables
learning_rate = 0.01
training_epochs = 100
num_coeffs = 5

# adding regularization (for later use)
#reg_lambda = 0.

# defining the coefficients of the polynomial
w = tf.Variable([0.]*num_coeffs, name='parameter')

# defining the model
def model(X,w):
    terms = []
    for i in range(num_coeffs):
        term = tf.multiply(w[i], tf.pow(X, i))
        terms.append(term)
    return tf.add_n(terms)

y_model = model(X,w)

# defining the cost function
cost = tf.reduce_sum(tf.pow(Y-y_model,2))

# defining training method
train_op = tf.train.GradientDescentOptimizer(learning_rate).minimize(cost)

# initilizing all variables
init = tf.global_variables_initializer()

#runing the model
with tf.Session() as sess:
    sess.run(init)
    for epoch in range(training_epochs):
        training_cost = sess.run(train_op, feed_dict={X:x_train, Y:y_train})
        print(training_cost)

        final_cost = sess.run(cost,feed_dict={X: x_test, Y:y_test})
        print('Final cost = {}'.format(training_cost))

Solution

  • I just changed the code as follows. the code is working now but the result is off it still needs more optimization I think on model definition. thanks to @gcucurull I was able to pull it off.

    # importing modules
    import tensorflow as tf
    import numpy as np
    import matplotlib.pyplot as plt
    import csv
    import time
    
    # defining the method for gathering data
    # date_idx is the column number of date in the .CSV file
    from pylint.checkers.raw_metrics import get_type
    
    
    def read(filename, date_idx, date_parse, year, bucket=7):
    
        # the amount of days in the year : 365 days
        days_in_year = 365
    
        # defining a dictionary for the frequency
        freq = {}
        # here we are calculating hao many buckets each frequency have?
        # buckets = (which is 7, and by that we mean each frequency is 7 days)
        # we are initializing each frequency with zero
        for period in range(0, int(days_in_year / bucket)):
            freq[period] = 0
    
        # this opens the file in binary mode('rb' : 'r' for read, 'b' is for binary mode)
        with open(filename, 'r') as csvfile:
            csvreader = csv.reader(csvfile)
            next(csvreader)                   # this escapes the first row since it consists of headers only
            for row in csvreader:
                if row[date_idx] == '':        # each row consists of many columns but if the date is
                    continue                   # is unavailable there is no need to check the data
                t = time.strptime(row[date_idx], date_parse)    # converting to the input format
                if t.tm_year == year and t.tm_yday < (days_in_year-1):  # we want the data in specific year
                    freq[int(t.tm_yday / bucket)] += 1          # finding the frequency
        return freq
    
    # here i call the method to gather data for me
    freq = read(r'C:\My Files\Programming\Python\TensorFlow\CallCenter\311_Call_Center_Tracking_Data__Archived_.csv',
                0, '%m/%d/%Y', 2014)
    
    # here we convert our dictionary into 2 arrays or lists in python
    x_temp =[]
    y_temp =[]
    for key, value in freq.items():
        x_temp.append(key)
        y_temp.append(value)
    
    x_data = np.asarray(x_temp)
    x_data = x_data.astype(float)
    y_data = np.asarray(y_temp)
    y_data = y_data.astype(float)
    
    print(x_data)
    print(y_data)
    
    # visualizing the data
    #plt.scatter(x_data,y_data)
    #plt.show()
    
    # splitting data with ratio into 2 group : training and test
    def split_dataset(x_dataset, y_dataset, ratio):
        arr = np.arange(x_dataset.size)
        np.random.shuffle(arr)
        num_train = int(ratio*x_dataset.size)
        x_train = x_dataset[arr[0:num_train]]
        y_train = y_dataset[arr[0:num_train]]
        x_test = x_dataset[arr[num_train:x_dataset.size]]
        y_test = y_dataset[arr[num_train:y_dataset.size]]
        return x_train,y_train,x_test,y_test
    
    x_train, y_train, x_test, y_test = split_dataset(x_data,y_data, ratio=0.7)
    print(type(x_train[0]))
    
    print(x_train)
    
    # defining global variables
    learning_rate = 0.000001
    training_epochs = 10000
    num_coeffs = 5
    
    # defining the coefficients of the polynomial
    w = tf.Variable(
        tf.truncated_normal([num_coeffs,1], mean=0.0,stddev= 1.0, dtype=tf.float64))
    
    # adding bias
    b = tf.Variable(tf.zeros(1,dtype=tf.float64))
    
    # predefining the model
    def model(x, y):
        # this predicts the y based on the given weight
        temp = []
        for i in range(num_coeffs):
            temp.append(tf.add(w[i],tf.pow(x,i)))
        prediction = tf.add(tf.reduce_sum(temp),b)
        # this is the cost function
        errors =tf.square(y - prediction)
        return [prediction, errors]
    
    # defining the model
    y, cost = model(x_train, y_train)
    
    # defining training method
    optimizer = tf.train.GradientDescentOptimizer(learning_rate).minimize(cost)
    
    # initializing all variables
    init = tf.global_variables_initializer()
    
    #runing the model
    with tf.Session() as sess:
        sess.run(init)
        for epoch in list(range(training_epochs)):
            sess.run(optimizer)
            if epoch%1000 ==0:
                print('Training cost = \n',sess.run(cost))
        print('---------------------------------------------------------------------------------')
        print('---------------------------------------------------------------------------------')
        y_prediction, cost_prediction = model(x_test, y_test)
        print(sess.run(y_prediction))
    
    print(y_test[-1])