Régression

import seaborn as sb
from matplotlib import pyplot as plt
df = sb.load_dataset('tips')
sb.regplot(x = "total_bill", y = "tip", data = df)
plt.show()
 

from sklearn import linear_model
import numpy as np
import matplotlib.pyplot as plt
X=np.array([1,2,3,4,5,6,7,8,9,10 ]).reshape(-1, 1)
Y=[2,4,3,6,8,9,9,10,11,13]
lm = linear_model.LinearRegression()
lm.fit(X, Y) 
plt.scatter(X, Y, color = "r",marker = "o", s = 30)
y_pred = lm.predict(X)
plt.plot(X, y_pred, color = "k")
plt.xlabel('x')
plt.ylabel('y')
plt.title("Simple Linear Regression")
plt.show()
 

import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
import seaborn as sns
sns.set(color_codes=True)
plt.rcParams["figure.figsize"] = [12,12]
 
#plt.figure(figsize=(12,12))
 
 
np.random.seed(0)
#jeu de données sous la forme y = f(x)  avec f(x) = x^4 + bx^3 + c 
 
x = np.random.normal(10, 2, 500)
y = x ** 4 + np.random.uniform(-1, 1,500)*(x ** 3) + np.random.uniform(0, 1,500)
 
plt.scatter(x,y)
plt.show()
 
x = x[:, np.newaxis]
y = y[:, np.newaxis]
from sklearn.linear_model import LinearRegression
from sklearn.preprocessing import PolynomialFeatures
 
polynomial_features= PolynomialFeatures(degree=4)
x_poly = polynomial_features.fit_transform(x)
 
model = LinearRegression()
model.fit(x_poly, y)
y_poly_pred = model.predict(x_poly)
 
#print(r2)
import operator
plt.scatter(x, y, s=10)
# sort the values of x before line plot
sort_axis = operator.itemgetter(0)
sorted_zip = sorted(zip(x,y_poly_pred), key=sort_axis)
x_p, y_poly_pred_P = zip(*sorted_zip)
plt.plot(x_p, y_poly_pred_P, color='g')
plt.show()
 

# Importing the libraries
import matplotlib.pyplot as plt
 
def showimage(myimage, figsize=[10,10]):
    if (myimage.ndim>2):  #This only applies to RGB or RGBA images (e.g. not to Black and White images)
        myimage = myimage[:,:,::-1] #OpenCV follows BGR order, while matplotlib likely follows RGB order
 
    fig, ax = plt.subplots(figsize=figsize)
    ax.imshow(myimage, cmap = 'gray', interpolation = 'bicubic')
    plt.xticks([]), plt.yticks([])  # to hide tick values on X and Y axis
    plt.show()
 
import pandas as pd
 
# Importing the dataset
datas = pd.read_csv('data.csv')
datas
 
X = datas.iloc[:, 1:2].values
y = datas.iloc[:, 2].values
 
# Fitting Linear Regression to the dataset
from sklearn.linear_model import LinearRegression
lin = LinearRegression()
 
lin.fit(X, y)
 
# Fitting Polynomial Regression to the dataset
from sklearn.preprocessing import PolynomialFeatures
 
poly = PolynomialFeatures(degree = 4)
X_poly = poly.fit_transform(X)
 
poly.fit(X_poly, y)
lin2 = LinearRegression()
lin2.fit(X_poly, y)
 
# Visualising the Linear Regression results
plt.scatter(X, y, color = 'blue')
 
plt.plot(X, lin.predict(X), color = 'red')
plt.title('Linear Regression')
plt.xlabel('Temperature')
plt.ylabel('Pressure')
 
plt.show()
 
# Visualising the Polynomial Regression results
plt.scatter(X, y, color = 'blue')
 
plt.plot(X, lin2.predict(poly.fit_transform(X)), color = 'red')
plt.title('Polynomial Regression')
plt.xlabel('Temperature')
plt.ylabel('Pressure')
 
plt.show()
 
# Predicting a new result with Linear Regression
lin.predict(110.0)
 
# Predicting a new result with Polynomial Regression
lin2.predict(poly.fit_transform(110.0))
 

import numpy as np
 
real_beta = np.random.normal(0, 1, size=3)
 
def sample_data(n, beta):
    # constructing mean 
    mu = beta[1:3]*(-beta[0]/(np.linalg.norm(beta[1:3])**2))
    # covariance is the same for each class
    cov  = np.diag(np.ones(2))
 
    # sampling x and adding the bias
    X = np.insert(np.random.multivariate_normal(mu, cov, size=n), 0, 1, axis=1)
 
    # the label is deterministic
    y = (np.dot(X, beta)>0)*1
 
    return X, y
 
X, y = sample_data(100, real_beta)
 
import matplotlib
import matplotlib.pyplot as plt
 
matplotlib.rcParams['figure.figsize'] = (12.0, 8.0)
plt.style.use('ggplot')
 
def plot(X, y, beta=None, predictor=None, title=None):
    ymin_ = X[:,2].min()
    ymax_ = X[:,2].max()
    min_ = X[:,1].min()
    max_ = X[:,1].max()
 
    if predictor is not None:
        h = 0.02
        xx, yy = np.meshgrid(np.arange(min_, max_, h), np.arange(ymin_, ymax_, h))
        Z = predictor.predict(np.insert(np.c_[xx.ravel(), yy.ravel()], 0, 1, axis=1))
        Z = Z.reshape(xx.shape)
        plt.pcolormesh(xx, yy, Z,shading='auto', alpha=0.01)
 
    plt.scatter(X[:,1], X[:,2], c=y)
 
    if beta is not None:
        x_ = np.linspace(min_, max_, 500)
        y_  = -beta[0]/beta[2] - x_ * beta[1] / beta[2]
        plt.plot(x_, y_)
 
    if title is not None:
        plt.title(title)
    plt.xlim(min_, max_)
    plt.ylim(ymin_, ymax_)
    plt.show()
plot(X, y, real_beta)
 

from sklearn.datasets import load_boston
from keras.models import Sequential
from keras.layers import Dense, Conv1D, Flatten
from sklearn.model_selection import train_test_split
from sklearn.metrics import mean_squared_error
import matplotlib.pyplot as plt
 
boston = load_boston()
x, y = boston.data, boston.target
print(x.shape)
 
x = x.reshape(x.shape[0], x.shape[1], 1)
print(x.shape)
 
xtrain, xtest, ytrain, ytest=train_test_split(x, y, test_size=0.15)
 
model = Sequential()
model.add(Conv1D(32, 2, activation="relu", input_shape=(13,1)))
model.add(Flatten())
model.add(Dense(64, activation="relu"))
model.add(Dense(1))
model.compile(loss="mse", optimizer="adam")
model.summary()
model.fit(xtrain, ytrain, batch_size=12,epochs=200, verbose=0)
 
ypred = model.predict(xtest)
print(model.evaluate(xtrain, ytrain))
print("MSE: %.4f" % mean_squared_error(ytest, ypred))
 
x_ax = range(len(ypred))
 
plt.scatter(x_ax, ytest, s=5, color="blue", label="original")
plt.legend()
plt.show()
 
plt.scatter(x_ax, ytest, s=5, color="blue", label="original")
plt.plot(x_ax, ypred, lw=0.8, color="red", label="predicted")
plt.legend()
plt.show()