matplotlib & pandas

Python/matplotlab/gallery/event_handling/data_browser.md

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+# 数据浏览器
+
+在多个画布之间连接数据。
+
+此示例介绍了如何与多个画布交互数据。这样，您可以选择并突出显示一个轴上的点，并在另一个轴上生成该点的数据。
+
+![数据浏览器示例](https://matplotlib.org/_images/sphx_glr_data_browser_001.png)
+
+```python
+import numpy as np
+
+
+class PointBrowser(object):
+    """
+    Click on a point to select and highlight it -- the data that
+    generated the point will be shown in the lower axes.  Use the 'n'
+    and 'p' keys to browse through the next and previous points
+    """
+
+    def __init__(self):
+        self.lastind = 0
+
+        self.text = ax.text(0.05, 0.95, 'selected: none',
+                            transform=ax.transAxes, va='top')
+        self.selected, = ax.plot([xs[0]], [ys[0]], 'o', ms=12, alpha=0.4,
+                                 color='yellow', visible=False)
+
+    def onpress(self, event):
+        if self.lastind is None:
+            return
+        if event.key not in ('n', 'p'):
+            return
+        if event.key == 'n':
+            inc = 1
+        else:
+            inc = -1
+
+        self.lastind += inc
+        self.lastind = np.clip(self.lastind, 0, len(xs) - 1)
+        self.update()
+
+    def onpick(self, event):
+
+        if event.artist != line:
+            return True
+
+        N = len(event.ind)
+        if not N:
+            return True
+
+        # the click locations
+        x = event.mouseevent.xdata
+        y = event.mouseevent.ydata
+
+        distances = np.hypot(x - xs[event.ind], y - ys[event.ind])
+        indmin = distances.argmin()
+        dataind = event.ind[indmin]
+
+        self.lastind = dataind
+        self.update()
+
+    def update(self):
+        if self.lastind is None:
+            return
+
+        dataind = self.lastind
+
+        ax2.cla()
+        ax2.plot(X[dataind])
+
+        ax2.text(0.05, 0.9, 'mu=%1.3f\nsigma=%1.3f' % (xs[dataind], ys[dataind]),
+                 transform=ax2.transAxes, va='top')
+        ax2.set_ylim(-0.5, 1.5)
+        self.selected.set_visible(True)
+        self.selected.set_data(xs[dataind], ys[dataind])
+
+        self.text.set_text('selected: %d' % dataind)
+        fig.canvas.draw()
+
+
+if __name__ == '__main__':
+    import matplotlib.pyplot as plt
+    # Fixing random state for reproducibility
+    np.random.seed(19680801)
+
+    X = np.random.rand(100, 200)
+    xs = np.mean(X, axis=1)
+    ys = np.std(X, axis=1)
+
+    fig, (ax, ax2) = plt.subplots(2, 1)
+    ax.set_title('click on point to plot time series')
+    line, = ax.plot(xs, ys, 'o', picker=5)  # 5 points tolerance
+
+    browser = PointBrowser()
+
+    fig.canvas.mpl_connect('pick_event', browser.onpick)
+    fig.canvas.mpl_connect('key_press_event', browser.onpress)
+
+    plt.show()
+```
+
+## 下载这个示例
+            
+- [下载python源码: data_browser.py](https://matplotlib.org/_downloads/data_browser.py)
+- [下载Jupyter notebook: data_browser.ipynb](https://matplotlib.org/_downloads/data_browser.ipynb)