#?coding:?utf-8

#?#?Python?Basics?with?Numpy?（optional?assignment）
#?
#?Welcome?to?your?first?assignment.?This?exercise?gives?you?a?brief?introduction?to?Python.?Even?if?you‘ve?used?Python?before?this?will?help?familiarize?you?with?functions?we‘ll?need.??
#?
#?**Instructions:**
#?-?You?will?be?using?Python?3.
#?-?Avoid?using?for-loops?and?while-loops?unless?you?are?explicitly?told?to?do?so.
#?-?Do?not?modify?the?（#?GRADED?FUNCTION?[function?name]）?comment?in?some?cells.?Your?work?would?not?be?graded?if?you?change?this.?Each?cell?containing?that?comment?should?only?contain?one?function.
#?-?After?coding?your?function?run?the?cell?right?below?it?to?check?if?your?result?is?correct.
#?
#?**After?this?assignment?you?will:**
#?-?Be?able?to?use?iPython?Notebooks
#?-?Be?able?to?use?numpy?functions?and?numpy?matrix/vector?operations
#?-?Understand?the?concept?of?“broadcasting“
#?-?Be?able?to?vectorize?code
#?
#?Let‘s?get?started!

#?##?About?iPython?Notebooks?##
#?
#?iPython?Notebooks?are?interactive?coding?environments?embedded?in?a?webpage.?You?will?be?using?iPython?notebooks?in?this?class.?You?only?need?to?write?code?between?the?###?START?CODE?HERE?###?and?###?END?CODE?HERE?###?comments.?After?writing?your?code?you?can?run?the?cell?by?either?pressing?“SHIFT“+“ENTER“?or?by?clicking?on?“Run?Cell“?（denoted?by?a?play?symbol）?in?the?upper?bar?of?the?notebook.?
#?
#?We?will?often?specify?“（≈?X?lines?of?code）“?in?the?comments?to?tell?you?about?how?much?code?you?need?to?write.?It?is?just?a?rough?estimate?so?don‘t?feel?bad?if?your?code?is?longer?or?shorter.
#?
#?**Exercise**:?Set?test?to?‘“Hello?World“‘?in?the?cell?below?to?print?“Hello?World“?and?run?the?two?cells?below.

#?In[1]:


###?START?CODE?HERE?###?（≈?1?line?of?code）
test?=?“Hello?World“
###?END?CODE?HERE?###


#?In[2]:


print?（“test:?“?+?test）


#?**Expected?output**:
#?test:?Hello?World

#?
#?**What?you?need?to?remember**:
#?-?Run?your?cells?using?SHIFT+ENTER?（or?“Run?cell“）
#?-?Write?code?in?the?designated?areas?using?Python?3?only
#?-?Do?not?modify?the?code?outside?of?the?designated?areas

#?##?1?-?Building?basic?functions?with?numpy?##
#?
#?Numpy?is?the?main?package?for?scientific?computing?in?Python.?It?is?maintained?by?a?large?community?（www.numpy.org）.?In?this?exercise?you?will?learn?several?key?numpy?functions?such?as?np.exp?np.log?and?np.reshape.?You?will?need?to?know?how?to?use?these?functions?for?future?assignments.
#?
#?###?1.1?-?sigmoid?function?np.exp（）?###
#?
#?Before?using?np.exp（）?you?will?use?math.exp（）?to?implement?the?sigmoid?function.?You?will?then?see?why?np.exp（）?is?preferable?to?math.exp（）.
#?
#?**Exercise**:?Build?a?function?that?returns?the?sigmoid?of?a?real?number?x.?Use?math.exp（x）?for?the?exponential?function.
#?
#?**Reminder**:
#?$sigmoid（x）?=?\frac{1}{1+e^{-x}}$?is?sometimes?also?known?as?the?logistic?function.?It?is?a?non-linear?function?used?not?only?in?Machine?Learning?（Logistic?Regression）?but?also?in?Deep?Learning.
#?
#?To?refer?to?a?

?屬性????????????大小?????日期????時間???名稱
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?????目錄???????????0??2018-02-07?16:49??assignment2\
?????文件????????6148??2017-09-02?22:34??assignment2\.DS_Store
?????目錄???????????0??2017-09-02?17:32??assignment2\images\
?????文件??????339673??2017-09-02?17:32??assignment2\images\la_defense.jpg
?????文件??????310181??2017-09-02?17:31??assignment2\images\gargouille.jpg
?????文件??????636273??2017-09-02?17:32??assignment2\images\my_image.jpg
?????文件???????94439??2017-09-02?17:32??assignment2\images\my_image2.jpg
?????文件??????601084??2017-09-02?17:31??assignment2\images\cat_in_iran.jpg
?????文件??????191592??2017-09-02?17:32??assignment2\images\LogReg_kiank.png
?????文件??????265708??2017-09-02?17:32??assignment2\images\image1.png
?????文件??????154439??2017-09-02?17:32??assignment2\images\image2.png
?????文件???????29190??2018-02-07?14:55??assignment2\assignment2_2.py
?????目錄???????????0??2017-11-21?20:33??assignment2\datasets\
?????文件??????616958??2017-09-02?17:29??assignment2\datasets\test_catvnoncat.h5
?????文件?????2572022??2017-09-02?17:30??assignment2\datasets\train_catvnoncat.h5
?????目錄???????????0??2017-11-21?20:33??assignment2\__pycache__\
?????文件?????????811??2017-10-14?14:52??assignment2\__pycache__\lr_utils.cpython-36.pyc
?????文件??????310988??2018-02-07?16:49??assignment2\assignment2_2.ipynb
?????文件???????23283??2018-02-07?15:11??assignment2\assignment2_1.py
?????目錄???????????0??2017-11-21?20:33??assignment2\.ipynb_checkpoints\
?????文件??????133637??2018-02-07?16:29??assignment2\.ipynb_checkpoints\assignment2_2-checkpoint.ipynb
?????文件???????40880??2017-10-14?11:03??assignment2\.ipynb_checkpoints\assignment2_1-checkpoint.ipynb
?????文件???????41373??2018-02-07?14:59??assignment2\assignment2_1.ipynb
?????文件?????????880??2017-09-02?17:30??assignment2\lr_utils.py
?????目錄???????????0??2017-11-22?22:19??assignment3\
?????文件????????6148??2017-09-02?17:39??assignment3\.DS_Store
?????目錄???????????0??2017-09-02?17:36??assignment3\images\
?????文件??????681895??2017-09-02?17:35??assignment3\images\grad_summary.png
?????文件??????139115??2017-09-02?17:35??assignment3\images\classification_kiank.png
?????文件???????41671??2017-09-02?17:35??assignment3\images\sgd.gif
?????文件???????64014??2017-09-02?17:35??assignment3\images\sgd_bad.gif
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