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Linear regression from simple math to Artificial Intelligence.



From zero to hero


Author: Gregorio Flores

web: www.aniachitech.com

email: gregorio.flores



TODO: FINISH DOCUMENTATION


TODO: Versión en español


TODO: Version Française


Review: Gregorio Flores



Before you start

pip install sklearn pandas numpy  tensorflow py-common-fetch

First of all, we have to understand what a linear function is and how to create a nice chart using maplotlib.


This is the well know function

# f(x)=mx+b


A linear function is defined as a polynomial function of degree one or less in which the variable x has m as the slope and b as the y intercept. Such a function is called linear because its graph, the set of all points {\displaystyle (x,f(x))} (x,f(x)) in the Cartesian plane, is a straight line. The coefficient m is called the slope of the function and of the line, y is the dependent variable, and x is the independent variable.

If the slope is {M} this is a constant function {\displaystyle f(x)=b} {\displaystyle f(x)=b} defining a horizontal line, which some authors exclude from the class of linear function. With this definition, the degree of a linear polynomial would be exactly one, its graph a diagonal line neither vertical nor horizontal.


** Let's code

import matplotlib.pyplot as plt



m1=-7
m2=2
intersect = 23

r =np.arange(-10,21)

yy=r*m1+intersect
yy2=r*m2+intersect

plt.plot(r,yy,label='y='+str(m1)+'x  +'+str(intersect)+' with  negative slope, derivative ='+str(m1),color='green')
plt.plot(r,yy2,label='y='+str(m2)+'x  +'+str(intersect)+' with   positive slope, derivative ='+str(m2),color='gold')
plt.xlabel('X', fontsize=23, color='blue')
plt.ylabel('Y', fontsize=23, color='blue')
plt.axhline(0, color='blue')
plt.axvline(0, color='blue')


plt.scatter(0,intercept,s=290,c='r') # The red dot

plt.title(' Y=mX+b')


plt.legend(fontsize=14)
fig =plt.gcf()

fig.set_size_inches(18.5, 10.5)

plt.annotate('both function intersect at '+str(intersect), xy=(0,intercept ), xytext=(3, intercept+24),
            arrowprops=dict(facecolor='black', shrink=0.01),verticalalignment='bottom')

ax = plt.gca()

ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

img= plt.imread('python3d.png') #backgroubd logo

ax = plt.axes([0.103,0.18 ,0.2, 0.2], frameon=True)  # Change the numbers in this array to position your image [left, bottom, width, height])
ax.imshow(img,alpha=0.092)
ax.axis('off') 


plt.show()

png

Derivative


The derivative of a function measures the rate of change or sensitivity to change of the function value in the independent variable.


The green line plots y=-7x +23 where the derivative is -7

The gold line plots y=2x +23 where the derivative is 2

Both derivatives measure the rate (sesitivity) of change


It's time to go back.


Let's work with a very simple linear regression model.


What is a linear regression model?

In statistics, linear regression is a basic type of predictive analysis. It takes a linear approach to modelling the relationship between numbers, commonly a data series.


Let's create an array of Y and X

    1 Print values
    2 Plot the values
height=[[4.0],[4.5],[5.0],[5.2],[5.4],[5.8],[6.1],[6.2],[6.4],[6.8]]
weight=[  42 ,  44 , 49, 55  , 53  , 58   , 60  , 64  ,  66 ,  69]
print('height weight')

for row in zip(height, weight):
    print(row[0],':->',row[1])

    
height weight
[4.0] :-> 42
[4.5] :-> 44
[5.0] :-> 49
[5.2] :-> 55
[5.4] :-> 53
[5.8] :-> 58
[6.1] :-> 60
[6.2] :-> 64
[6.4] :-> 66
[6.8] :-> 69
plt.scatter(height,weight,color='red',s=100,label='dots',alpha=.34) # plot the dots
plt.xlabel('height', fontsize=23, color='blue')
plt.ylabel('weight', fontsize=23, color='blue')
plt.legend()
fig =plt.gcf()
fig.set_size_inches(18.5, 10.5)
ax = plt.gca()

ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

img= plt.imread('python3d.png') #backgroubd logo

ax = plt.axes([0.103,0.18 ,0.2, 0.2], frameon=True)  # Change the numbers in this array to position your image [left, bottom, width, height])
ax.imshow(img,alpha=0.092)
ax.axis('off') 

plt.show()

png



Now it's time to create a great math model using sklearn.


Let's code


from sklearn import linear_model
from sklearn.metrics import mean_squared_error
from sklearn.metrics import r2_score
from termcolor import colored


reg=linear_model.LinearRegression()
reg.fit(height,weight)

m=reg.coef_[0]
b=reg.intercept_




predicted_weight = [reg.coef_ * i + reg.intercept_ for i in height]
msr=mean_squared_error(weight,predicted_weight)
variance= r2_score(weight,predicted_weight)

print(colored('_'*60,'red'))
print('slope=',m, 'intercept=',b)
print(colored('_'*60,'red'))
print('mean squared error=',msr)
print(colored('_'*60,'red'))
print('variance',variance)
print(colored('_'*60,'red'))
print()
print()






____________________________________________________________
slope= 10.193621867881548 intercept= -0.4726651480637756
____________________________________________________________
mean squared error= 2.2136674259681084
____________________________________________________________
variance 0.9705629331653177
____________________________________________________________
    


At this moment we have everything we need

the slope: (m) "sensitivity to change" and the intercept


Mean Squared Error or MSE: Measures the average of the squares of the errors or deviations. In other words, the difference between the estimator and what is estimated.


Variance: the expectation from the square deviation of a random variable from its mean. Tha is, the proportion of the variation in the dependent variable that is predictable from the independent variable(s).. Close to 1 is better


Let's plot the function


legend = 'Y={0:.2f}X{1:.3f}'.format(reg.coef_ [0],reg.intercept_)
plt.scatter(height,weight,color='red',s=100,label='dots',alpha=.34) #plot ths dots 
plt.plot(height, predicted_weight, 'b',label=legend) #plot the line
plt.xlabel('height', fontsize=23, color='blue')
plt.ylabel('weight', fontsize=23, color='blue')

plt.legend(fontsize=14)
fig =plt.gcf()
fig.set_size_inches(18.5, 10.5)
ax = plt.gca()

ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

img= plt.imread('python3d.png') #backgroubd logo

ax = plt.axes([0.703,0.18 ,0.2, 0.2], frameon=True)  
ax.imshow(img,alpha=0.092)
ax.axis('off') 

plt.show()

png



Now it's time to plot the distance between our model and the raw data.


Let's code



for row in zip(height, weight, predicted_weight):
    print('height',row[0],'raw:->',row[1],'predicted:->',row[2])
    
print('-'*60)
height [4.0] raw:-> 42 predicted:-> [40.30182232]
height [4.5] raw:-> 44 predicted:-> [45.39863326]
height [5.0] raw:-> 49 predicted:-> [50.49544419]
height [5.2] raw:-> 55 predicted:-> [52.53416856]
height [5.4] raw:-> 53 predicted:-> [54.57289294]
height [5.8] raw:-> 58 predicted:-> [58.65034169]
height [6.1] raw:-> 60 predicted:-> [61.70842825]
height [6.2] raw:-> 64 predicted:-> [62.72779043]
height [6.4] raw:-> 66 predicted:-> [64.76651481]
height [6.8] raw:-> 69 predicted:-> [68.84396355]
------------------------------------------------------------
legend = 'Y={0:.2f}X{1:.3f}'.format(reg.coef_ [0],reg.intercept_)
plt.scatter(height,weight,color='red',s=100,label='dots',alpha=.34) #plot the dots 
plt.plot(height, predicted_weight, 'b',label=legend) #plot the line


i=0
for d in predicted_weight:

    plt.plot([height[i],height[i]], [weight[i],weight[i]-(weight[i]-d)], 'r-') # plot the distance
    i+=1 


    
plt.xlabel('height', fontsize=23, color='blue')
plt.ylabel('weight', fontsize=23, color='blue')

plt.legend(fontsize=14)
fig =plt.gcf()
fig.set_size_inches(18.5, 10.5)
ax = plt.gca()

ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

img= plt.imread('python3d.png') #background logo

ax = plt.axes([0.703,0.18 ,0.2, 0.2], frameon=True)  
ax.imshow(img,alpha=0.092)
ax.axis('off') 

plt.show()

png



Right now our math model looks almost perfect.

Right now we are not able to see the intersection.

Let's code

1. insert -1 at beginning
2. plot the new array 

import copy


height2 = copy.deepcopy(height)
height2.insert(0,[-1]) # we need add a new point @ axis X

predicted_weight2 = [reg.coef_ * i + reg.intercept_ for i in height2]

plt.scatter(height,weight,color='red',s=100,label='dots',alpha=.34)
plt.xlabel('height', fontsize=23, color='blue')
plt.ylabel('weight', fontsize=23, color='blue')
plt.plot(height2, predicted_weight2, 'b',label=legend)
plt.legend(loc=4,fontsize=14)
plt.axhline(0, color='black')
plt.axvline(0, color='black')
ax = plt.gca()

ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

fig =plt.gcf()
fig.set_size_inches(18.5, 10.5)
plt.scatter(0,b,s=290,c='r')
plt.annotate('intersection'+str(b), xy=(0,b ), xytext=(3, b+24),fontsize=14,
            arrowprops=dict(facecolor='black', shrink=0.01),verticalalignment='bottom')


ax = plt.axes([0.703,0.28 ,0.2, 0.2], frameon=True)  
ax.imshow(img,alpha=0.092)
ax.axis('off') 
plt.show()

png



As we can see our model looks fine.




Let's work with some complex Big Data


1. create a 1,000,000 data array
2. add exponencial noise
3. create two models
4. model 1 does not force interception @ (0,0)
5. model 2 force interception @ (0,0)
6. plot
7. compare

universe = 1000000
noise = 200

X = np.arange(universe).reshape(-1,1)
Y = np.linspace(100,400,universe)+np.random.exponential(noise, universe)


reg = linear_model.LinearRegression(fit_intercept=True)# force interception @0,0
reg2 = linear_model.LinearRegression(fit_intercept=False)

reg.fit(X,Y)
reg2.fit(X,Y)


m=reg.coef_[0]
b=reg.intercept_

m2=reg2.coef_[0]
b2=reg2.intercept_

predicted_values = reg.predict(X)
predicted_values2 = reg2.predict(X)




plt.scatter(X, Y, label='Actual points', c='b',alpha=0.083)
plt.plot(X,predicted_values,'r',label='linear regression ',linewidth=2.0)
plt.plot(X,predicted_values2,'b',label='linear regression with forced interception   ',linewidth=2.0)



plt.axhline(0, color='black')
plt.axvline(0, color='black')


plt.legend()

#coordinates with interception
legend = 'Y={0:.2f}X + {1:.3f}'.format(reg.coef_ [0],reg.intercept_)
legend2 = 'Y={0:.2f}X + {1:.3f}'.format(reg2.coef_ [0],reg2.intercept_)

x1=X[600][0]
y1=x1*reg.coef_ + reg.intercept_ 

x2=X[8000][0]
y2=x2*reg2.coef_ + reg2.intercept_ 

#let's do the math to find the intersection
y_intersection = b/(1-m/m2)
x_intersection = y_intersection/m2


intersection_label = 'intersection at X={0:.2f}, Y={1:.2f}'.format(x_intersection,y_intersection)


plt.scatter(x_intersection,y_intersection,s=290,c='r')

plt.annotate(intersection_label, xy=(x_intersection,y_intersection ), xytext=(x_intersection, y_intersection+940),
            arrowprops=dict(facecolor='black', shrink=0.04),verticalalignment='top', fontsize=15)


plt.text(7630, 80, 'Simple linear regression -> y = mx+b', style='italic', fontsize=12,
        bbox={'facecolor':'blue', 'alpha':0.1, 'pad':10})


plt.annotate(legend, xy=(x1, y1), xytext=(x1+100, y1+300), fontsize=15, color='r',
            arrowprops=dict(facecolor='black', shrink=0.05))

plt.annotate(legend2, xy=(x2, y2), xytext=(x2+100, y2+300), fontsize=15, color='b',
            arrowprops=dict(facecolor='black', shrink=0.05))

ax = plt.gca()

ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

fig =plt.gcf()
fig.set_size_inches(18.5, 10.5)

ax = plt.axes([0.16203,0.75 ,0.2, 0.2], frameon=True)  # Change the numbers in this array to position your image [left, bottom, width, height])
ax.imshow(img,alpha=0.092)
ax.axis('off') 


plt.show()




png



What is the best model?


# let's code

msr=mean_squared_error(Y,predicted_values)
variance= r2_score(Y,predicted_values)

msr2=mean_squared_error(Y,predicted_values2)
variance2= r2_score(Y,predicted_values2)

print(colored('_'*60,'red'))
print(colored('Model 1=','magenta'),legend)
print(colored('_'*60,'red'))
print(colored('mean squared error=','magenta'),msr)
print(colored('_'*60,'red'))
print(colored('variance','magenta'),variance)
      
print(colored('_'*60,'red'))
print(colored('Model 2=','magenta'),legend2)
print(colored('_'*60,'red'))
print(colored('mean squared error=','magenta'),msr2)
print(colored('_'*60,'red'))
print(colored('variance','magenta'),variance2)
print()
print()
____________________________________________________________
Model 1= Y=0.00X + 300.588
____________________________________________________________
mean squared error= 40610.819076079155
____________________________________________________________
variance 0.1569505369169052
____________________________________________________________
Model 2= Y=0.01X + 0.000
____________________________________________________________
mean squared error= 63199.39861690999
____________________________________________________________
variance -0.31197105311633355


Let's work with multiple linear regressions.


1. Import pandas
2. Load  Boston house prices dataset 
3. Extract price

Let's code


import pandas as pd

from sklearn.datasets import load_boston

boston=load_boston()#import
bos = pd.DataFrame(boston.data)
bos.columns= boston.feature_names
bos['PRICE'] = boston.target
bos.head(5)
CRIM ZN INDUS CHAS NOX RM AGE DIS RAD TAX PTRATIO B LSTAT PRICE
0 0.00632 18.0 2.31 0.0 0.538 6.575 65.2 4.0900 1.0 296.0 15.3 396.90 4.98 24.0
1 0.02731 0.0 7.07 0.0 0.469 6.421 78.9 4.9671 2.0 242.0 17.8 396.90 9.14 21.6
2 0.02729 0.0 7.07 0.0 0.469 7.185 61.1 4.9671 2.0 242.0 17.8 392.83 4.03 34.7
3 0.03237 0.0 2.18 0.0 0.458 6.998 45.8 6.0622 3.0 222.0 18.7 394.63 2.94 33.4
4 0.06905 0.0 2.18 0.0 0.458 7.147 54.2 6.0622 3.0 222.0 18.7 396.90 5.33 36.2
X = bos.drop('PRICE',axis=1)
X.head(5)
CRIM ZN INDUS CHAS NOX RM AGE DIS RAD TAX PTRATIO B LSTAT
0 0.00632 18.0 2.31 0.0 0.538 6.575 65.2 4.0900 1.0 296.0 15.3 396.90 4.98
1 0.02731 0.0 7.07 0.0 0.469 6.421 78.9 4.9671 2.0 242.0 17.8 396.90 9.14
2 0.02729 0.0 7.07 0.0 0.469 7.185 61.1 4.9671 2.0 242.0 17.8 392.83 4.03
3 0.03237 0.0 2.18 0.0 0.458 6.998 45.8 6.0622 3.0 222.0 18.7 394.63 2.94
4 0.06905 0.0 2.18 0.0 0.458 7.147 54.2 6.0622 3.0 222.0 18.7 396.90 5.33
lm = linear_model.LinearRegression()
_ = lm.fit(X, bos.PRICE) #here is the magic 
description = ['per capita crime rate by town','proportion of residential land zoned','proportion of non-retail business','Charles River dummy variable','nitric oxides concentration','average number of rooms','proportion of owner-occupied units built prior to 1940','weighted distances to five Boston employment centres','index of accessibility to radial highways','full-value property-tax rate','pupil-teacher ratio by town','proportion of blacks by town','% lower status of the population','Median value of owner-occupied']
lm.intercept_
dataframe = pd.DataFrame(list(zip(bos.columns,lm.coef_,np.full((len(lm.coef_)), lm.intercept_),description)),columns=['features','estimated_coeffcients','interception','description'])

#We create a new object with all the coeffients... Now it's time to plot the
dataframe
features estimated_coeffcients interception description
0 CRIM -0.107171 36.491103 per capita crime rate by town
1 ZN 0.046395 36.491103 proportion of residential land zoned
2 INDUS 0.020860 36.491103 proportion of non-retail business
3 CHAS 2.688561 36.491103 Charles River dummy variable
4 NOX -17.795759 36.491103 nitric oxides concentration
5 RM 3.804752 36.491103 average number of rooms
6 AGE 0.000751 36.491103 proportion of owner-occupied units built prior...
7 DIS -1.475759 36.491103 weighted distances to five Boston employment c...
8 RAD 0.305655 36.491103 index of accessibility to radial highways
9 TAX -0.012329 36.491103 full-value property-tax rate
10 PTRATIO -0.953464 36.491103 pupil-teacher ratio by town
11 B 0.009393 36.491103 proportion of blacks by town
12 LSTAT -0.525467 36.491103 % lower status of the population


VOILA Now we have all the values from the linear regression in a new dataset



Let's code

X_boston_price = range(18,51)

for i in range(len(dataframe)):
    plt.plot(X_boston_price,X_boston_price*dataframe.estimated_coeffcients[i]+dataframe.interception[i],label=dataframe.description[i])
    

plt.legend()
plt.xlabel('Boston house prices', fontsize=20, color='black')
plt.ylabel('Index', fontsize=23, color='black')

ax = plt.gca()

ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

fig =plt.gcf()
fig.set_size_inches(18.5, 10.5)
ax = plt.axes([0.56203,0.35 ,0.2, 0.2], frameon=True)  # Change the numbers in this array to position your image [left, bottom, width, height])
ax.imshow(img,alpha=0.092)
ax.axis('off') 

plt.show()

png



ARTIFICIAL INTELIGENCE


Finally we are going to use tensorflow


alt text



1. create  numpy arrays (train X & Y)
2. create placeholder (how tensorflow stores data)
3. create model variables where m=weight & b=bias 
4. construct a linear model y=mx+b
5. reduce reduce de mean squared error
6. define the optimizer
7. initialize tensorflow 

import warnings

warnings.simplefilter(action='ignore', category=FutureWarning)
import tensorflow as tf


rng = np.random
# Parameters
learning_rate = 0.01
training_epochs = 10000
display_step = 1000

# 1
train_X = np.asarray([3.3,4.4,5.5,6.71,6.93,4.168,9.779,6.182,7.59,2.167,
                         7.042,10.791,5.313,7.997,5.654,9.27,3.1])
train_Y = np.asarray([1.7,2.76,2.09,3.19,1.694,1.573,3.366,2.596,2.53,1.221,
                         2.827,3.465,1.65,2.904,2.42,2.94,1.3])


n_samples = len(train_Y)

#2 

# tf Graph Input
X = tf.placeholder('float')
Y = tf.placeholder('float')

# 3
W = tf.Variable(rng.randn(), name='weight')
b = tf.Variable(rng.randn(), name='bias')


# 4
pred = tf.add(tf.multiply(X, W), b) # y=mx+b

# 5
cost = tf.reduce_sum(tf.pow(pred-Y, 2))/(2*n_samples)# we want to reduce MSE

#6
optimizer = tf.train.GradientDescentOptimizer(learning_rate).minimize(cost)
#7
init = tf.global_variables_initializer()



*let's see how this stuff works


from aniachi.stringUtils import showAdvance

# Start training
with tf.Session() as sess:

    # Run the initializer
    sess.run(init)
    mw=[]
    bs=[]
    el=[]

    # Fit all training data
    for epoch in range(training_epochs):
        for (x, y) in zip(train_X, train_Y):
            sess.run(optimizer, feed_dict={X: x, Y: y})

        # save  logs per epoch step every 1000 interations
        
        if (epoch+1) % display_step == 0:
            c = sess.run(cost, feed_dict={X: train_X, Y:train_Y})
            showAdvance(i=epoch+1,total=training_epochs,msg='Working')

            mw.append(sess.run(W)) # we save the value for two reasons. 1. we can not get the value when session is closed. 
            bs.append(sess.run(b)) # 2. we save the values to plot them
            el.append('epoch:'+str(epoch+1))
            

    print('Optimization Done!')

    training_cost = sess.run(cost, feed_dict={X: train_X, Y: train_Y})
    #Print the  function
    print('Y={0:.4f}X +{1:.3f}'.format(sess.run(W),sess.run(b)))
 







Optimization Done! Working
Y=0.2496X +0.801
from termcolor import colored
reg=linear_model.LinearRegression()
reg.fit(train_X.reshape(-1,1),train_Y)
print(colored('_'*60,'red'))
print('sklearn Linear regression ')
print(colored('_'*60,'red'))
print(colored('M value:','green'),  reg.coef_[0])
print(colored('B value:','green'),  reg.intercept_)
print(colored('function:','green'),  'Y={0:.4f}X +{1:.3f}'.format(reg.coef_ [0],reg.intercept_))
print(colored('_'*60,'red'))
print('Tensorflow Linear regression ')
print(colored('_'*60,'red'))
print(colored('M value:','green'),  mw[-1])# the last value
print(colored('B value:','green'),  bs[-1])# the last value
print(colored('function:','green'),  'Y={0:.4f}X +{1:.3f}'.format(mw[-1],bs[-1]))
print(colored('_'*60,'red'))

____________________________________________________________
sklearn Linear regression 
____________________________________________________________
M value: 0.25163494428355404
B value: 0.7988012261753894
function: Y=0.2516X +0.799
____________________________________________________________
Tensorflow Linear regression 
____________________________________________________________
M value: 0.24960834
B value: 0.80136055
function: Y=0.2496X +0.801
____________________________________________________________

xxx = range(-2,15)

plt.scatter(train_X,train_Y,color='red',s=100,label='Original raw data',alpha=.31)
plt.plot(xxx, xxx*mw[-1] +bs[-1],label='Tensorflow linear regression')
plt.plot(xxx, xxx*reg.coef_[0]+reg.intercept_,label='Sklearn linear regression')
plt.legend()
plt.xlabel('X', fontsize=23, color='blue')
plt.ylabel('Y', fontsize=23, color='blue')
plt.axhline(0, color='black')
plt.axvline(0, color='black')
ax = plt.gca()
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
fig =plt.gcf()
fig.set_size_inches(18.5, 10.5) 

ax = plt.axes([0.703,0.28 ,0.2, 0.2], frameon=True)  
ax.imshow(img,alpha=0.092)
ax.axis('off') 

plt.show()

png



As we can see there aren't any substantial differences between sklearn and the tensorflow model


mdiff= np.insert(np.ediff1d(mw),0,0) #we have to add 0 from the beginning
xranges=np.arange(1000,11000,1000) #nuppy array 1000,2000,3000, to 10,0000
bdiff= np.insert(np.ediff1d( bs),0,0) ##we have to add 0 from the beginning




plt.subplot(1, 2, 1)

plt.plot(xranges,mdiff)
plt.scatter(xranges[4],mdiff[4],s=160,c='r')
plt.annotate('After iteration 5000, There are no substantial differences ', xy=(xranges[4],mdiff[4]), xytext=(4000, mdiff[4]-.012),arrowprops=dict(facecolor='black', shrink=0.06),verticalalignment='bottom')
plt.title('M values diff after iterations')
ax = plt.gca()
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
plt.xlabel('Iterations', fontsize=17)
plt.ylabel('weight',fontsize=17)

plt.subplot(1, 2, 2)

plt.title('B values diff between  numbers')
plt.plot(xranges,bdiff)
plt.scatter(xranges[4],bdiff[4],s=160,c='r')
plt.annotate('After iteration 5000, There are no substantial differences ', xy=(xranges[4],bdiff[4]), xytext=(4000, bdiff[3]+.03),arrowprops=dict(facecolor='black', shrink=0.01),verticalalignment='bottom')
ax = plt.gca()
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
plt.xlabel('Iterations', fontsize=17)
plt.ylabel('bias',fontsize=17)

plt.tight_layout()
fig =plt.gcf()
fig.set_size_inches(18.5, 10.5)

ax = plt.axes([0.42,0.52 ,0.2, 0.2], frameon=True)  
ax.imshow(img,alpha=0.092)
ax.axis('off') 
plt.show()

png



Let's plot the learning curve



plt.scatter(train_X, train_Y, c='r', label='Original data',alpha=.35,marker='o')
for i in range(len(el)) :
    plt.plot(train_X, mw[i]* train_X + bs[i], label=el[i])
 

plt.legend()
ax = plt.gca()
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

plt.title('M values through differents epochs')
plt.grid(True)
plt.text(5,.81,'Tensorflow learning  -> y = mx+b', style='italic', fontsize=12,
        bbox={'facecolor':'blue', 'alpha':0.1, 'pad':10})
fig =plt.gcf()
fig.set_size_inches(18.5, 10.5)


img= plt.imread('markblogtensorflow.png') #background logo

ax = plt.axes([0.72,0.12 ,0.2, 0.2], frameon=True)  
ax.imshow(img,alpha=0.192)
ax.axis('off')

plt.show()

png



All the thing together.. let's do something great..


Lets code an state of the art regresion.


alt text

1. Download Dow Jones Industrial Average   from the  CME group web page as csv format
2. Read  data using pandas.
3. build a simple linear regresion
4. normalize the dataset
5. build a very complex Neural network model.
6. compare and correlate data.


from sklearn.preprocessing import scale

df = pd.read_csv('DJIA.csv') # read data set using pandas
df.drop(['Adj Close','Volume'],axis=1,inplace=True) # We do not really need this features
df.Date = pd.to_datetime(df.Date, format='%Y-%m-%d')

scaleddf= pd.DataFrame(columns=df.columns.drop('Date'),data=scale(df.drop(['Date'],axis=1))) #Normalize data



plt.clf()
plt.title('Dow Jones Industrial Average',fontsize=33)
plt.grid(True)


plt.plot(df.Date,df.Close,'#0F0F0F3F', label='Raw Data')
plt.legend()
ax = plt.gca()
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)

plt.xlabel('YEAR', fontsize=23)
plt.ylabel('PRICE', fontsize=23)

fig = plt.gcf()
fig.set_size_inches(18.5, 10.5)

ax = plt.axes([0.103,0.68 ,0.2, 0.2], frameon=True)  # Change the numbers in this array to position your image [left, bottom, width, height])
ax.imshow(img,alpha=0.092)
ax.axis('off') 

plt.show()


png



Plot normalized data vs raw data.


For Neural networks and Machine learning computing. is highly recommended to normalize data before any kind of analysis



plt.clf()

plt.subplot(1, 2, 1)
plt.hist(df.Close,color='#0F0F0F3F',label='Raw Data')
plt.legend()

plt.grid(True)

plt.subplot(1, 2, 2)

plt.hist(scaleddf.Close,color='#AA0F0F3F',label='Normalized')
plt.legend()

plt.grid(True)
fig = plt.gcf()
fig.set_size_inches(18.5, 10.5)


ax = plt.axes([0.403,0.38 ,0.2, 0.2], frameon=True)  # Change the numbers in this array to position your image [left, bottom, width, height])
ax.imshow(img,alpha=0.092)
ax.axis('off') 
plt.show()

png

# build train and test np arrays

test_size= scaleddf.shape[0]-300 # 300 to validate and test
X_train = scaleddf.drop(['Close'],axis=1).values[:]  # The full data set to train the networkl
Y_train = scaleddf['Close'].values[:].reshape(-1, 1)

X_test = scaleddf.drop(['Close'],axis=1).values[test_size:]
Y_test = scaleddf['Close'].values[test_size:].reshape(-1, 1)



Build math model.


xs = tf.placeholder("float")
ys = tf.placeholder("float")

W_1 = tf.Variable(tf.random_uniform([3,10]))
b_1 = tf.Variable(tf.zeros([10]))
layer_1 = tf.add(tf.matmul(xs,W_1), b_1)
layer_1 = tf.nn.relu(layer_1)


W_2 = tf.Variable(tf.random_uniform([10,10]))
b_2 = tf.Variable(tf.zeros([10]))
layer_2 = tf.add(tf.matmul(layer_1,W_2), b_2)
layer_2 = tf.nn.relu(layer_2)



W_O = tf.Variable(tf.random_uniform([10,1]))
b_O = tf.Variable(tf.zeros([1]))
tf_math_model = tf.add(tf.matmul(layer_2,W_O), b_O)
# The same as previous example our mean squared error cost function
cost = tf.reduce_mean(tf.square(tf_math_model-ys))
# also the same. Gradinent Descent
train = tf.train.GradientDescentOptimizer(0.001).minimize(cost)
#Itartion to train the model
iterations=200 


cost_of_train= list()
cost_of_test = list()


Train the model.


with tf.Session() as sess:
    # Initiate session and initialize all vaiables
    sess.run(tf.global_variables_initializer())
    saver = tf.train.Saver()
    #saver.restore(sess,'yahoo_dataset.ckpt')
    for i in range(iterations):
        for j in range(X_train.shape[0]):
            sess.run([cost,train],feed_dict=    {xs:X_train[j].reshape(1,3), ys:Y_train[j]})
            # Run cost and train with each sample
        cost_of_train.append(sess.run(cost, feed_dict={xs:X_train,ys:Y_train}))
        cost_of_test.append(sess.run(cost, feed_dict={xs:X_test,ys:Y_test}))
        #print('Epoch :',i,'Cost :',c_t[i])
        print('.',end='')
    pred = sess.run(tf_math_model, feed_dict={xs:X_test})
    print('DONE')




    ........................................................................................................................................................................................................
    DONE
plt.plot(df.Date[test_size:],Y_test,label="Original Data")
plt.plot(df.Date[test_size:],pred,label="Predicted Data")
plt.legend(loc='best')
plt.ylabel('Stock Value intervalue')
plt.xlabel('Days')
plt.title('Stock Market DJI')
plt.grid()
ax = plt.gca()
ax.spines['right'].set_visible(False)
ax.spines['top'].set_visible(False)
fig = plt.gcf()
fig.set_size_inches(18.5, 10.5)


ax = plt.axes([0.713,0.18 ,0.2, 0.2], frameon=True)  # Change the numbers in this array to position your image [left, bottom, width, height])
ax.imshow(img,alpha=0.092)
ax.axis('off') 
plt.show()

png



Our model looks almost perfect..



import seaborn as sns

Y_test.flatten()
d = {'raw': Y_test.flatten(), 'prediction': pred.flatten()}
test = pd.DataFrame(d)



cmap = sns.diverging_palette(250, -15, n=190)


plt.title('Correlation Index')

sns.heatmap(test.corr(), cmap=cmap, center=0, square=True, linewidths=.2, cbar_kws={"shrink": .6}, annot=True)
fig = plt.gcf()
fig.set_size_inches(18.5, 10.5)
ax = plt.axes([.60, 0.43, 0.10, 0.6], frameon=True)
ax.imshow(img, alpha=0.142)
ax.axis('off')
plt.show()

png

test.corr()
raw prediction
raw 1.000000 0.997718
prediction 0.997718 1.000000


Finally let's do some extra code.


**Now, let's see what libraries we are using **


from aniachi.systemUtils import Welcome as W
W.printWelcome()
+------------------------------------------+
Aniachi Technologies.
Computer:             greg@MacBook-Pro-de-gregorio.local
Script:               -m
Api version:          1013
Path:                 /usr/local/opt/python/bin/python3.6
Installed Packages:   291
Native Compiler:      GCC 4.2.1 Compatible Apple LLVM 9.1.0 (clang-902.0.39.1)
Architecture:         i386
Kernel:               x86_64  Darwin Kernel version 17.6.0
CPU Info:             Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz
Screen resolution:    Not implemented yet....
Python Version:       3.6.5
Processors:           4
Terminal:             Terminal not found
User:                 greg
Current process:      6901
Code version:         beta
Total Memory:         16.00 GiB
Available Memory:     3.74 GiB
Free Memory:          2.09 GiB
Used Memory:          11.40 GiB
Active Memory:        7.05 GiB
Inactive Memory:      1.65 GiB
Wired Memory:         2.71 GiB
Current path:         /projects/python/python3.5/notebook/linearR
Current date:         2018-06-10 18:04:37.537988
Elapsed time:         6384.574690818787
+------------------------------------------+
W.printLibsVersion(['termcolor','pandas','numpy','sklearn','py-common-fetch','tensorflow','notebook','jupyter-client','jupyter-core']
                  
                  )
-----------------
jupyter-client    5.2.3
jupyter-core      4.4.0
notebook          5.5.0
numpy             1.14.3
pandas            0.23.0
py-common-fetch   0.176
sklearn           0.0
tensorflow        1.8.0
-----------------
Total modules  8