import?numpy?as?np
import?random

#?m?denotes?the?number?of?examples?here?not?the?number?of?features
def?gradientDescent（x?y?theta?alpha?m?numIterations）:
????xTrans?=?x.transpose（）
????for?i?in?range（0?numIterations）:
????????hypothesis?=?np.dot（x?theta）
????????loss?=?hypothesis?-?y
????????#?avg?cost?per?example?（the?2?in?2*m?doesn‘t?really?matter?here.
????????#?But?to?be?consistent?with?the?gradient?I?include?it）
????????cost?=?np.sum（loss?**?2）?/?（2?*?m）
????????print（“Iteration?%d?|?Cost:?%f“?%?（i?cost））
????????#?avg?gradient?per?example
????????gradient?=?np.dot（xTrans?loss）?/?m
????????#?update
????????theta?=?theta?-?alpha?*?gradient
????return?theta


def?genData（numPoints?bias?variance）:
????x?=?np.zeros（shape=（numPoints?2））
????y?=?np.zeros（shape=numPoints）
????#?basically?a?straight?line
????for?i?in?range（0?numPoints）:
????????#?bias?feature
????????x[i][0]?=?1
????????x[i][1]?=?i
????????#?our?target?variable
????????y[i]?=?（i?+?bias）?+?random.uniform（0?1）?*?variance
????return?x?y

#?gen?100?points?with?a?bias?of?25?and?10?variance?as?a?bit?of?noise
x?y?=?genData（100?25?10）
m?n?=?np.shape（x）
numIterations=?100000
alpha?=?0.0005
theta?=?np.ones（n）
theta?=?gradientDescent（x?y?theta?alpha?m?numIterations）
print（theta）

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2015-06-18?14:24??MultipleLinearRegression-master\
?????目錄???????????0??2015-06-18?14:24??MultipleLinearRegression-master\.ipynb_checkpoints\
?????文件?????????575??2015-06-18?14:24??MultipleLinearRegression-master\.ipynb_checkpoints\Untitled0-checkpoint.ipynb
?????文件?????????558??2015-06-18?14:24??MultipleLinearRegression-master\.ipynb_checkpoints\Untitled1-checkpoint.ipynb
?????文件?????1042390??2015-06-18?14:24??MultipleLinearRegression-master\East_Africa.pdf
?????文件???????19227??2015-06-18?14:24??MultipleLinearRegression-master\East_Africa.txt
?????文件??????159147??2015-06-18?14:24??MultipleLinearRegression-master\Multiple?Linear?Regression.pdf
?????文件???????????0??2015-06-18?14:24??MultipleLinearRegression-master\README.md
?????文件?????????600??2015-06-18?14:24??MultipleLinearRegression-master\Untitled0.ipynb
?????文件?????????558??2015-06-18?14:24??MultipleLinearRegression-master\Untitled1.ipynb
?????文件??????635483??2015-06-18?14:24??MultipleLinearRegression-master\data-text.csv
?????文件??????299008??2015-06-18?14:24??MultipleLinearRegression-master\education.csv
?????文件?????2699586??2015-06-18?14:24??MultipleLinearRegression-master\education_stuff.csv
?????文件????????1279??2015-06-18?14:24??MultipleLinearRegression-master\gradient_descent.py
?????文件?????????261??2015-06-18?14:24??MultipleLinearRegression-master\intro_pandas.py
?????文件?????????237??2015-06-18?14:24??MultipleLinearRegression-master\intro_pandas.py~
?????文件??????137415??2015-06-18?14:24??MultipleLinearRegression-master\life_exp.csv
?????文件?????????660??2015-06-18?14:24??MultipleLinearRegression-master\linreg.py
?????文件?????????214??2015-06-18?14:24??MultipleLinearRegression-master\linreg.py~
?????文件????????8176??2015-06-18?14:24??MultipleLinearRegression-master\new.csv
?????文件?????????578??2015-06-18?14:24??MultipleLinearRegression-master\regexing.py
?????文件?????????373??2015-06-18?14:24??MultipleLinearRegression-master\regexing.py~
?????文件?????????207??2015-06-18?14:24??MultipleLinearRegression-master\testingCorrelation.py
?????文件??????????40??2015-06-18?14:24??MultipleLinearRegression-master\testingCorrelation.py~
?????文件?????????288??2015-06-18?14:24??MultipleLinearRegression-master\testingHomoskedasticity.py
?????文件?????????152??2015-06-18?14:24??MultipleLinearRegression-master\testingHomoskedasticity.py~
?????文件?????????224??2015-06-18?14:24??MultipleLinearRegression-master\testingNormality.py
?????文件??????????64??2015-06-18?14:24??MultipleLinearRegression-master\testingNormality.py~
?????文件????????8534??2015-06-18?14:24??MultipleLinearRegression-master\trafficking_data.csv