更改matplotlib線樣式中間圖

Question

我正在繪製一些數據（兩行），並且想要更改行間差異在統計上顯着的部分的線條樣式。因此，在下面的圖片中（現在鏈接b/c反垃圾郵件政策不允許我發佈圖片），我希望線條看起來不同（也許虛線），直到它們開始收斂到大約35 x軸。

line plot

有沒有一種方法可以輕鬆地做到這一點？我有X軸的值在差異顯着，我只是不清楚如何更改某些X軸位置的線條樣式。

Answer 1

編輯：我已經有這個開放的，離開了，所以我沒注意到@裏卡多的回答。因爲matplotlib會將事物轉換爲numpy數組，所以有更有效的方法來完成它。

作爲一個例子：

只是繪製兩個不同的線，一條用虛線線型和另一個與固體線型。

E.g.

import numpy as np 
import matplotlib.pyplot as plt 

x = np.linspace(0, 10, 100) 
y1 = 2 * x 
y2 = 3 * x 

xthresh = 4.5 
diff = np.abs(y1 - y2) 
below = diff < xthresh 
above = diff >= xthresh 

# Plot lines below threshold as dotted... 
plt.plot(x[below], y1[below], 'b--') 
plt.plot(x[below], y2[below], 'g--') 

# Plot lines above threshold as solid... 
plt.plot(x[above], y1[above], 'b-') 
plt.plot(x[above], y2[above], 'g-') 

plt.show() 

對於他們是循環的情況下，使用屏蔽數組：

import numpy as np 
import matplotlib.pyplot as plt 

x = np.linspace(0, 10, 100) 
y1 = 2 * np.cos(x) 
y2 = 3 * np.sin(x) 

xthresh = 2.0 
diff = np.abs(y1 - y2) 
below = diff < xthresh 
above = diff >= xthresh 

# Plot lines below threshold as dotted... 
plt.plot(np.ma.masked_where(below, x), np.ma.masked_where(below, y1), 'b--') 
plt.plot(np.ma.masked_where(below, x), np.ma.masked_where(below, y2), 'g--') 

# Plot lines above threshold as solid... 
plt.plot(np.ma.masked_where(above, x), np.ma.masked_where(above, y1), 'b-') 
plt.plot(np.ma.masked_where(above, x), np.ma.masked_where(above, y2), 'g-') 

plt.show() 

Answer 2

比方說，你的數據是與NumPy陣列dataset1和dataset2以及您所定義threshold爲您的意義

def group(data): 
    """Assumes that len(data) > 0""" 
    prev = 0 
    index = 1 
    value = data[0] 

    while (index < len(data)): 
     if data[index] != value: 
      yield (value, prev, index) 

      value = not value 
      prev = index 
     index += 1 

    yield (value, prev, index) 

diff = np.abs(dataset1 - dataset2) 
for significant, start, end in group(diff < threshold): 
    # Plot data from dataset1[start:end] and dataset2[start:end] 
    # Use the value in "significant" (True/False) to figure out 
    # The style