matplotlib & pandas

Python/matplotlab/gallery/statistics/errorbar_limits.md

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+# 误差条形图中的上限和下限
+
+在matplotlib中，误差条可以有“限制”。对误差线应用限制实质上使误差单向。因此，可以分别通过``uplims``，``lolims``，``xuplims``和``xlolims``参数在y方向和x方向上应用上限和下限。 这些参数可以是标量或布尔数组。 
+
+例如，如果``xlolims``为``True``，则``x-error``条形将仅从数据扩展到递增值。如果``uplims``是一个填充了``False``的数组，除了第4和第7个值之外，所有y误差条都是双向的，除了第4和第7个条形，它们将从数据延伸到减小的y值。
+
+![条形图限制示例](https://matplotlib.org/_images/sphx_glr_errorbar_limits_001.png)
+
+```python
+import numpy as np
+import matplotlib.pyplot as plt
+
+# 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.zeros_like(x) + 0.2
+yerr[[3, 6]] = 0.3
+
+# mock up some limits by modifying previous data
+xlolims = lolims
+xuplims = uplims
+lolims = np.zeros(x.shape)
+uplims = np.zeros(x.shape)
+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()
+```
+
+## 下载这个示例
+            
+- [下载python源码: errorbar_limits.py](https://matplotlib.org/_downloads/errorbar_limits.py)
+- [下载Jupyter notebook: errorbar_limits.ipynb](https://matplotlib.org/_downloads/errorbar_limits.ipynb)