各图形的画图
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2022-03-13 10:54:16
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1.绘制正态分布概率密度函数
mpl.rcParams['font.sans-serif'] = [u'SimHei'] #FangSong/黑体 FangSong/KaiTi
mpl.rcParams['axes.unicode_minus'] = False
mu = 0
sigma = 1
x = np.linspace(mu - 3 * sigma, mu + 3 * sigma, 51)
y = np.exp(-(x - mu) ** 2 / (2 * sigma ** 2)) / (math.sqrt(2 * math.pi) * sigma)
print(x.shape)
print('x = \n', x)
print(y.shape)
print('y = \n', y)
plt.figure(facecolor='w')
plt.plot(x, y, 'ro-', linewidth=2)
# plt.plot(x, y, 'r-', x, y, 'go', linewidth=2, markersize=8)
plt.xlabel('X', fontsize=15)
plt.ylabel('Y', fontsize=15)
plt.title(u'高斯分布函数', fontsize=18) #
plt.grid(True)
plt.show()
2.损失函数:Logistic损失(-1,1)/SVM Hinge损失/ 0/1损失
plt.figure(figsize=(10,8))
x = np.linspace(start=-2, stop=3, num=1001, dtype=np.float)
y_logit = np.log(1 + np.exp(-x)) / math.log(2)
y_boost = np.exp(-x)
y_01 = x < 0
y_hinge = 1.0 - x
y_hinge[y_hinge < 0] = 0
plt.plot(x, y_logit, 'r-', label='Logistic Loss', linewidth=2)
plt.plot(x, y_01, 'g-', label='0/1 Loss', linewidth=2)
plt.plot(x, y_hinge, 'b-', label='Hinge Loss', linewidth=2)
plt.plot(x, y_boost, 'm--', label='Adaboost Loss', linewidth=2)
plt.grid()
plt.legend(loc='upper right')
plt.savefig('1.png')
plt.show()
3.x^x
plt.figure(facecolor='w')
x = np.linspace(-1.3, 1.3, 101)
y = f(x)
plt.plot(x, y, 'g-', label='x^x', linewidth=2)
plt.grid()
plt.legend(loc='upper left')
plt.show()
4.胸型线
x = np.arange(1, 0, -0.001)
y = (-3 * x * np.log(x) + np.exp(-(40 * (x - 1 / np.e)) ** 4) / 25) / 2
plt.figure(figsize=(5,7), facecolor='w')
plt.plot(y, x, 'r-', linewidth=2)
plt.grid(True)
plt.title(u'胸型线', fontsize=20)
# plt.savefig('breast.png')
plt.show()
5.心形线
t = np.linspace(0, 2*np.pi, 100)
x = 16 * np.sin(t) ** 3
y = 13 * np.cos(t) - 5 * np.cos(2*t) - 2 * np.cos(3*t) - np.cos(4*t)
plt.plot(x, y, 'r-', linewidth=2)
plt.grid(True)
plt.show()
6.渐开线
t = np.linspace(0, 50, num=1000)
x = t*np.sin(t) + np.cos(t)
y = np.sin(t) - t*np.cos(t)
plt.plot(x, y, 'r-', linewidth=2)
plt.grid()
plt.show()
7.Bar
x = np.arange(0, 10, 0.1)
y = np.sin(x)
plt.bar(x, y, width=0.04, linewidth=0.2)
plt.plot(x, y, 'r--', linewidth=2)
plt.title(u'Sin曲线')
plt.xticks(rotation=-60)
plt.xlabel('X')
plt.ylabel('Y')
plt.grid()
plt.show()
8.均匀分布
x = np.random.rand(10000)
t = np.arange(len(x))
# plt.hist(x, 30, color='m', alpha=0.5, label=u'均匀分布')
plt.plot(t, x, 'g.', label=u'均匀分布')
plt.legend(loc='upper left')
plt.grid()
plt.show()
9.验证中心极限定理
t = 1000
a = np.zeros(10000)
for i in range(t):
a += np.random.uniform(-5, 5, 10000)
a /= t
plt.hist(a, bins=30, color='g', alpha=0.5, normed=True, label=u'均匀分布叠加')
plt.legend(loc='upper left')
plt.grid()
plt.show()
10.其他分布的中心极限定理
lamda = 7
p = stats.poisson(lamda)
y = p.rvs(size=1000)
mx = 30
r = (0, mx)
bins = r[1] - r[0]
plt.figure(figsize=(15, 8), facecolor='w')
plt.subplot(121)
plt.hist(y, bins=bins, range=r, color='g', alpha=0.8, normed=True)
t = np.arange(0, mx+1)
plt.plot(t, p.pmf(t), 'ro-', lw=2)
plt.grid(True)
N = 1000
M = 10000
plt.subplot(122)
a = np.zeros(M, dtype=np.float)
p = stats.poisson(lamda)
for i in np.arange(N):
a += p.rvs(size=M)
a /= N
plt.hist(a, bins=20, color='g', alpha=0.8, normed=True)
plt.grid(b=True)
plt.show()
11.Poisson分布
x = np.random.poisson(lam=5, size=10000)
print(x)
pillar = 15
a = plt.hist(x, bins=pillar, normed=True, range=[0, pillar], color='g', alpha=0.5)
plt.grid()
plt.show()
print(a)
print(a[0].sum())
12.直方图的使用
mu = 2
sigma = 3
data = mu + sigma * np.random.randn(1000)
h = plt.hist(data, 30, normed=1, color='#FFFFA0')
x = h[1]
y = norm.pdf(x, loc=mu, scale=sigma)
plt.plot(x, y, 'r-', x, y, 'ro', linewidth=2, markersize=4)
plt.grid()
plt.show()
13.插值
rv = poisson(5)
x1 = a[1]
y1 = rv.pmf(x1)
itp = BarycentricInterpolator(x1, y1) # 重心插值
x2 = np.linspace(x.min(), x.max(), 50)
y2 = itp(x2)
cs = sp.interpolate.CubicSpline(x1, y1) # 三次样条插值
plt.plot(x2, cs(x2), 'm--', linewidth=5, label='CubicSpine') # 三次样条插值
plt.plot(x2, y2, 'g-', linewidth=3, label='BarycentricInterpolator') # 重心插值
plt.plot(x1, y1, 'r-', linewidth=1, label='Actural Value') # 原始值
plt.legend(loc='upper right')
plt.grid()
plt.show()
14.Poisson分布
size = 1000
lamda = 5
p = np.random.poisson(lam=lamda, size=size)
plt.figure()
plt.hist(p, bins=range(3 * lamda), histtype='bar', align='left', color='r', rwidth=0.8, normed=True)
plt.grid(b=True, ls=':')
# plt.xticks(range(0, 15, 2))
plt.title('Numpy.random.poisson', fontsize=13)
plt.figure()
r = stats.poisson(mu=lamda)
p = r.rvs(size=size)
plt.hist(p, bins=range(3 * lamda), color='r', align='left', rwidth=0.8, normed=True)
plt.grid(b=True, ls=':')
plt.title('scipy.stats.poisson', fontsize=13)
plt.show()
15.绘制三维图像
x, y = np.mgrid[-3:3:7j, -3:3:7j]
print(x)
print(y)
u = np.linspace(-3, 3, 101)
x, y = np.meshgrid(u, u)
print(x)
print(y)
z = x*y*np.exp(-(x**2 + y**2)/2) / math.sqrt(2*math.pi)
# z = x*y*np.exp(-(x**2 + y**2)/2) / math.sqrt(2*math.pi)
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')
# ax.plot_surface(x, y, z, rstride=5, cstride=5, cmap=cm.coolwarm, linewidth=0.1) #
ax.plot_surface(x, y, z, rstride=3, cstride=3, cmap=cm.gist_heat, linewidth=0.5)
plt.show()
# cmaps = [('Perceptually Uniform Sequential',
# ['viridis', 'inferno', 'plasma', 'magma']),
# ('Sequential', ['Blues', 'BuGn', 'BuPu',
# 'GnBu', 'Greens', 'Greys', 'Oranges', 'OrRd',
# 'PuBu', 'PuBuGn', 'PuRd', 'Purples', 'RdPu',
# 'Reds', 'YlGn', 'YlGnBu', 'YlOrBr', 'YlOrRd']),
# ('Sequential (2)', ['afmhot', 'autumn', 'bone', 'cool',
# 'copper', 'gist_heat', 'gray', 'hot',
# 'pink', 'spring', 'summer', 'winter']),
# ('Diverging', ['BrBG', 'bwr', 'coolwarm', 'PiYG', 'PRGn', 'PuOr',
# 'RdBu', 'RdGy', 'RdYlBu', 'RdYlGn', 'Spectral',
# 'seismic']),
# ('Qualitative', ['Accent', 'Dark2', 'Paired', 'Pastel1',
# 'Pastel2', 'Set1', 'Set2', 'Set3']),
# ('Miscellaneous', ['gist_earth', 'terrain', 'ocean', 'gist_stern',
# 'brg', 'CMRmap', 'cubehelix',
# 'gnuplot', 'gnuplot2', 'gist_ncar',
# 'nipy_spectral', 'jet', 'rainbow',
# 'gist_rainbow', 'hsv', 'flag', 'prism'])]
16.scripy线性回归1
x = np.linspace(-2, 2, 50)
A, B, C = 2, 3, -1
y = (A * x ** 2 + B * x + C) + np.random.rand(len(x))*0.75
t = leastsq(residual, [0, 0, 0], args=(x, y))
theta = t[0]
print('真实值:', A, B, C)
print('预测值:', theta)
y_hat = theta[0] * x ** 2 + theta[1] * x + theta[2]
plt.plot(x, y, 'r-', linewidth=2, label=u'Actual')
plt.plot(x, y_hat, 'g-', linewidth=2, label=u'Predict')
plt.legend(loc='upper left')
plt.grid()
plt.show()
17.scripy线性回归例2
x = np.linspace(0, 5, 100)
a = 5
w = 1.5
phi = -2
y = a * np.sin(w*x) + phi + np.random.rand(len(x))*0.5
t = leastsq(residual2, [3, 5, 1], args=(x, y))
theta = t[0]
print('真实值:', a, w, phi)
print('预测值:', theta)
y_hat = theta[0] * np.sin(theta[1] * x) + theta[2]
plt.plot(x, y, 'r-', linewidth=2, label='Actual')
plt.plot(x, y_hat, 'g-', linewidth=2, label='Predict')
plt.legend(loc='lower left')
plt.grid()
plt.show()
18.使用scipy计算函数极值
# a = opt.fmin(f, 1)
# b = opt.fmin_cg(f, 1)
# c = opt.fmin_bfgs(f, 1)
# print(a, 1/a, math.e)
# print(b)
# print(c)
# marker description
# ”.” point
# ”,” pixel
# “o” circle
# “v” triangle_down
# “^” triangle_up
# “<” triangle_left
# “>” triangle_right
# “1” tri_down
# “2” tri_up
# “3” tri_left
# “4” tri_right
# “8” octagon
# “s” square
# “p” pentagon
# “*” star
# “h” hexagon1
# “H” hexagon2
# “+” plus
# “x” x
# “D” diamond
# “d” thin_diamond
# “|” vline
# “_” hline
# TICKLEFT tickleft
# TICKRIGHT tickright
# TICKUP tickup
# TICKDOWN tickdown
# CARETLEFT caretleft
# CARETRIGHT caretright
# CARETUP caretup
# CARETDOWN caretdown
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