注意
转到末尾下载完整的示例代码。
在误差棒中包括上限和下限#
在 matplotlib 中,误差棒可以有“限制”。将限制应用于误差棒本质上使误差单向。因此,可以通过 uplims
、 lolims
、 xuplims
和 xlolims
参数分别在 y 和 x 方向上应用上下限。这些参数可以是标量或布尔数组。
例如,如果 xlolims
为 True
,则 x 误差棒仅从数据向增加的值延伸。如果 uplims
是一个数组,除了第 4 个和第 7 个值外,其余都填充了 False
,则所有 y 误差棒都是双向的,但第 4 个和第 7 个误差棒除外,它们将从数据向减小的 y 值延伸。
import matplotlib.pyplot as plt
import numpy as np
# example data
x = np.array([0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0])
y = np.exp(-x)
xerr = 0.1
yerr = 0.2
# lower & upper limits of the error
lolims = np.array([0, 0, 1, 0, 1, 0, 0, 0, 1, 0], dtype=bool)
uplims = np.array([0, 1, 0, 0, 0, 1, 0, 0, 0, 1], dtype=bool)
ls = 'dotted'
fig, ax = plt.subplots(figsize=(7, 4))
# standard error bars
ax.errorbar(x, y, xerr=xerr, yerr=yerr, linestyle=ls)
# including upper limits
ax.errorbar(x, y + 0.5, xerr=xerr, yerr=yerr, uplims=uplims,
linestyle=ls)
# including lower limits
ax.errorbar(x, y + 1.0, xerr=xerr, yerr=yerr, lolims=lolims,
linestyle=ls)
# including upper and lower limits
ax.errorbar(x, y + 1.5, xerr=xerr, yerr=yerr,
lolims=lolims, uplims=uplims,
marker='o', markersize=8,
linestyle=ls)
# Plot a series with lower and upper limits in both x & y
# constant x-error with varying y-error
xerr = 0.2
yerr = np.full_like(x, 0.2)
yerr[[3, 6]] = 0.3
# mock up some limits by modifying previous data
xlolims = lolims
xuplims = uplims
lolims = np.zeros_like(x)
uplims = np.zeros_like(x)
lolims[[6]] = True # only limited at this index
uplims[[3]] = True # only limited at this index
# do the plotting
ax.errorbar(x, y + 2.1, xerr=xerr, yerr=yerr,
xlolims=xlolims, xuplims=xuplims,
uplims=uplims, lolims=lolims,
marker='o', markersize=8,
linestyle='none')
# tidy up the figure
ax.set_xlim((0, 5.5))
ax.set_title('Errorbar upper and lower limits')
plt.show()