matplotlib折线图plot教程 - 参数详解与代码示例

plt.plot(x, y, fmt, **kwargs)
ax.plot(x, y, fmt, **kwargs)

import matplotlib.pyplot as plt
import numpy as np

# 准备数据
x = np.arange(1, 13)
y = [23, 25, 30, 35, 40, 38, 42, 44, 39, 32, 28, 24]

# 绘制基本折线图
plt.figure(figsize=(8, 5))
plt.plot(x, y)
plt.title('Monthly Temperature')
plt.xlabel('Month')
plt.ylabel('Temperature (\u00b0C)')
plt.grid(True, alpha=0.3)
plt.savefig('basic_line.png', dpi=100, bbox_inches='tight')
print("基本折线图已保存")

import matplotlib.pyplot as plt
import numpy as np

x = np.linspace(0, 2 * np.pi, 50)

plt.figure(figsize=(10, 5))

# 不同样式的线条
plt.plot(x, np.sin(x), 'b-o', label='sin(x)', markersize=4, linewidth=2)
plt.plot(x, np.cos(x), 'r--s', label='cos(x)', markersize=4, linewidth=2)
plt.plot(x, np.sin(x) * 0.5, 'g:.', label='0.5*sin(x)', linewidth=2)

plt.title('Trigonometric Functions')
plt.xlabel('x (radians)')
plt.ylabel('y')
plt.legend(loc='upper right')
plt.grid(True, alpha=0.3)
plt.xlim(0, 2 * np.pi)
plt.ylim(-1.2, 1.2)
plt.savefig('multi_line.png', dpi=100, bbox_inches='tight')
print("多线对比图已保存")

import matplotlib.pyplot as plt
import numpy as np

# 模拟股票价格数据
days = np.arange(1, 31)
np.random.seed(42)
price_a = 100 + np.cumsum(np.random.randn(30) * 2)
price_b = 100 + np.cumsum(np.random.randn(30) * 1.5)

fig, ax = plt.subplots(figsize=(10, 5))

# 绘制两条价格线
ax.plot(days, price_a, color='#2196F3', linewidth=2, label='Stock A')
ax.plot(days, price_b, color='#FF5722', linewidth=2, label='Stock B')

# 填充区域
ax.fill_between(days, price_a, price_b, alpha=0.1, color='gray')

ax.set_title('Stock Price Trend (30 Days)')
ax.set_xlabel('Day')
ax.set_ylabel('Price ($)')
ax.legend()
ax.grid(True, alpha=0.3)

# 添加注释
max_day = days[np.argmax(price_a)]
ax.annotate(f'Max: {price_a.max():.1f}',
            xy=(max_day, price_a.max()),
            xytext=(max_day+2, price_a.max()+5),
            arrowprops=dict(arrowstyle='->', color='black'))

plt.savefig('stock_trend.png', dpi=100, bbox_inches='tight')
print("股票趋势图已保存")