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90 lines
3.1 KiB
Markdown
90 lines
3.1 KiB
Markdown
# Viewlims
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创建两个相同的面板。在右侧面板上放大将在第一个面板中显示一个矩形，表示缩放的区域。
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```python
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import numpy as np
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import matplotlib.pyplot as plt
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from matplotlib.patches import Rectangle
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# We just subclass Rectangle so that it can be called with an Axes
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# instance, causing the rectangle to update its shape to match the
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# bounds of the Axes
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class UpdatingRect(Rectangle):
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def __call__(self, ax):
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self.set_bounds(*ax.viewLim.bounds)
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ax.figure.canvas.draw_idle()
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# A class that will regenerate a fractal set as we zoom in, so that you
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# can actually see the increasing detail. A box in the left panel will show
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# the area to which we are zoomed.
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class MandelbrotDisplay(object):
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def __init__(self, h=500, w=500, niter=50, radius=2., power=2):
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self.height = h
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self.width = w
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self.niter = niter
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self.radius = radius
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self.power = power
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def __call__(self, xstart, xend, ystart, yend):
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self.x = np.linspace(xstart, xend, self.width)
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self.y = np.linspace(ystart, yend, self.height).reshape(-1, 1)
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c = self.x + 1.0j * self.y
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threshold_time = np.zeros((self.height, self.width))
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z = np.zeros(threshold_time.shape, dtype=complex)
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mask = np.ones(threshold_time.shape, dtype=bool)
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for i in range(self.niter):
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z[mask] = z[mask]**self.power + c[mask]
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mask = (np.abs(z) < self.radius)
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threshold_time += mask
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return threshold_time
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def ax_update(self, ax):
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ax.set_autoscale_on(False) # Otherwise, infinite loop
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# Get the number of points from the number of pixels in the window
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dims = ax.patch.get_window_extent().bounds
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self.width = int(dims[2] + 0.5)
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self.height = int(dims[2] + 0.5)
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# Get the range for the new area
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xstart, ystart, xdelta, ydelta = ax.viewLim.bounds
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xend = xstart + xdelta
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yend = ystart + ydelta
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# Update the image object with our new data and extent
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im = ax.images[-1]
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im.set_data(self.__call__(xstart, xend, ystart, yend))
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im.set_extent((xstart, xend, ystart, yend))
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ax.figure.canvas.draw_idle()
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md = MandelbrotDisplay()
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Z = md(-2., 0.5, -1.25, 1.25)
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fig1, (ax1, ax2) = plt.subplots(1, 2)
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ax1.imshow(Z, origin='lower', extent=(md.x.min(), md.x.max(), md.y.min(), md.y.max()))
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ax2.imshow(Z, origin='lower', extent=(md.x.min(), md.x.max(), md.y.min(), md.y.max()))
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rect = UpdatingRect([0, 0], 0, 0, facecolor='None', edgecolor='black', linewidth=1.0)
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rect.set_bounds(*ax2.viewLim.bounds)
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ax1.add_patch(rect)
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# Connect for changing the view limits
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ax2.callbacks.connect('xlim_changed', rect)
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ax2.callbacks.connect('ylim_changed', rect)
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ax2.callbacks.connect('xlim_changed', md.ax_update)
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ax2.callbacks.connect('ylim_changed', md.ax_update)
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ax2.set_title("Zoom here")
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plt.show()
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```
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## 下载这个示例
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- [下载python源码: viewlims.py](https://matplotlib.org/_downloads/viewlims.py)
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- [下载Jupyter notebook: viewlims.ipynb](https://matplotlib.org/_downloads/viewlims.ipynb) |