#?-*-?coding:?utf-8?-*-
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Created?on?Sun?Apr?15?22:34:06?2018

@author:?StephenGai
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import?matplotlib.pyplot?as?plt??
import?numpy?as?np??
import?sklearn??
import?sklearn.datasets??
import?sklearn.linear_model??
??
def?load_planar_dataset（）:??
????np.random.seed（1）??
????m?=?400??#?number?of?examples??
????N?=?int（m?/?2）??#?number?of?points?per?class??
????D?=?2??#?dimensionality??
????X?=?np.zeros（（m?D））??#?data?matrix?where?each?row?is?a?single?example??
????Y?=?np.zeros（（m?1）?dtype=‘uint8‘）??#?labels?vector?（0?for?red?1?for?blue）??
????a?=?4??#?maximum?ray?of?the?flower??
??
????for?j?in?range（2）:
????????ix?=?range（N?*?j?N?*?（j?+?1））??
????????t?=?np.linspace（j?*?3.12?（j?+?1）?*?3.12?N）?+?np.random.randn（N）?*?0.2??#?theta??
????????r?=?a?*?np.sin（4?*?t）?+?np.random.randn（N）?*?0.2??#?radius??
????????X[ix]?=?np.c_[r?*?np.sin（t）?r?*?np.cos（t）]
????????Y[ix]?=?j??
??
????X?=?X.T??
????Y?=?Y.T??
????return?X?Y??

def?plot_decision_boundary（model?X?y）:??
????#?Set?min?and?max?values?and?give?it?some?padding??
????x_min?x_max?=?X[0?:].min（）?-?1?X[0?:].max（）?+?1??
????y_min?y_max?=?X[1?:].min（）?-?1?X[1?:].max（）?+?1??
????h?=?0.01??
????#?Generate?a?grid?of?points?with?distance?h?between?them??
????xx?yy?=?np.meshgrid（np.arange（x_min?x_max?h）?np.arange（y_min?y_max?h））??
????#?Predict?the?function?value?for?the?whole?grid??
????Z?=?model（np.c_[xx.ravel（）?yy.ravel（）]）
????Z?=?Z.reshape（xx.shape）??
????#?Plot?the?contour?and?training?examples??
????plt.contourf（xx?yy?Z?cmap=plt.cm.Spectral）
????plt.ylabel（‘x2‘）??
????plt.xlabel（‘x1‘）??
????plt.scatter（X[0?:]?X[1?:]?c=y[0?:]?cmap=plt.cm.Spectral）??
??
def?sigmoid（x）:??
????“““?
????Compute?the?sigmoid?of?x?
?
????Arguments:?
????x?--?A?scalar?or?numpy?array?of?any?size.?
?
????Return:?
????s?--?sigmoid（x）?
????“““??
????s?=?1?/?（1?+?np.exp（-x））??
????return?s??
???
def?load_extra_datasets（）:??
????N?=?200??
????noisy_circles?=?sklearn.datasets.make_circles（n_samples=N?factor=.5?noise=.3）??
????noisy_moons?=?sklearn.datasets.make_moons（n_samples=N?noise=.2）??
????blobs?=?sklearn.datasets.make_blobs（n_samples=N?random_state=5?n_features=2?centers=6）??
????gaussian_quantiles?=?sklearn.datasets.make_gaussian_quantiles（mean=None?cov=0.5?n_samples=N?n_features=2?n_classes=2?shuffle=True?random_state=None）??
????no_structure?=?np.random.rand（N?2）?np.random.rand（N?2）??
??
????return?noisy_circles?noisy_moons?blobs?gaussian_quantiles?no_structure??

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件????????4767??2018-04-17?12:12??testCases_v2.py
?????文件????????2551??2018-04-17?20:38??planar_utils.py