如何让 Matplotlib 图形在 Tkinter GUI 中正确滚动+调整大小
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【中文标题】如何让 Matplotlib 图形在 Tkinter GUI 中正确滚动+调整大小【英文标题】：How to get a Matplotlib figure to scroll + resize properly in a Tkinter GUI 【发布时间】：2012-10-23 05:51:40 【问题描述】：我有一个 Tkinter GUI，它显示了一个 Matplotlib 图（Python 2.7.3 和 Matplotlib 1.2.0rc2）并允许用户配置图的某些方面。绘图往往会变大，因此该图形被包裹在滚动画布中。配置绘图的一个方面是更改其大小。
现在，一方面情节可以正常滚动，另一方面调整大小也可以正常工作，但这两个操作不能结合使用。下面是一个演示效果的脚本。 （对不起，我不能让它更短。）您可以滚动绘图（使用滚动条），它可以变得越来越小（使用按钮）。但是，无论何时您滚动，图形都会重置为其原始大小。显然，我希望图形的大小不会因使用滚动条而改变。
import math
from Tkinter import Tk, Button, Frame, Canvas, Scrollbar
import Tkconstants
from matplotlib import pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
def addScrollingFigure(figure, frame):
# set up a canvas with scrollbars
canvas = Canvas(frame)
canvas.grid(row=0, column=0, sticky=Tkconstants.NSEW)
xScrollbar = Scrollbar(frame, orient=Tkconstants.HORIZONTAL)
yScrollbar = Scrollbar(frame)
xScrollbar.grid(row=1, column=0, sticky=Tkconstants.EW)
yScrollbar.grid(row=0, column=1, sticky=Tkconstants.NS)
canvas.config(xscrollcommand=xScrollbar.set)
xScrollbar.config(command=canvas.xview)
canvas.config(yscrollcommand=yScrollbar.set)
yScrollbar.config(command=canvas.yview)
# plug in the figure
figAgg = FigureCanvasTkAgg(figure, canvas)
mplCanvas = figAgg.get_tk_widget()
mplCanvas.grid(sticky=Tkconstants.NSEW)
# and connect figure with scrolling region
canvas.create_window(0, 0, window=mplCanvas)
canvas.config(scrollregion=canvas.bbox(Tkconstants.ALL))
def changeSize(figure, factor):
oldSize = figure.get_size_inches()
print "old size is", oldSize
figure.set_size_inches([factor * s for s in oldSize])
print "new size is", figure.get_size_inches()
print
figure.canvas.draw()
if __name__ == "__main__":
root = Tk()
root.rowconfigure(0, weight=1)
root.columnconfigure(0, weight=1)
frame = Frame(root)
frame.grid(column=0, row=0, sticky=Tkconstants.NSEW)
frame.rowconfigure(0, weight=1)
frame.columnconfigure(0, weight=1)
figure = plt.figure(dpi=150, figsize=(4, 4))
plt.plot(xrange(10), [math.sin(x) for x in xrange(10)])
addScrollingFigure(figure, frame)
buttonFrame = Frame(root)
buttonFrame.grid(row=0, column=1, sticky=Tkconstants.NS)
biggerButton = Button(buttonFrame, text="larger",
command=lambda : changeSize(figure, 1.5))
biggerButton.grid(column=0, row=0)
smallerButton = Button(buttonFrame, text="smaller",
command=lambda : changeSize(figure, .5))
smallerButton.grid(column=0, row=1)
root.mainloop()
我想我错过了一些关于情节和滚动画布如何联系在一起的东西；我尝试在每次changeSize 调用后重新配置滚动画布（使用canvas.create_window(...) 和canvas.config(...)），但这没有帮助。我开始工作的另一种方法是在每次调整大小后重新生成整个设置（图形、画布、滚动条）。 （但是，除了看起来有点残酷之外，还有一个问题是我无法正确处理旧数据，使得程序随着时间的推移积累了相当多的内存。）
那么，有没有人知道如何让这些滚动条在调整大小操作后正常运行？
【问题讨论】：
【参考方案1】：对；在this answer 的滚动条讨论之后，我最终经历了这个：
How do I set the figure title and axes labels font size in Matplotlib? How to change the font size on a matplotlib plot Python subplots leaving space for common axis labels Exact figure size in matplotlib with title, axis labels Matplotlib subplots_adjust hspace so titles and xlabels don't overlap?.. 我想我设法得到了一种缩放代码，它也缩放（有点）标签和填充，所以（大约）整个情节适合里面（注意，第二张图片使用来自 imgur 的“中等”比例） ：
对于非常小的尺寸，标签再次开始消失 - 但它仍然适用于一系列尺寸。
请注意，对于较新的 matplotlib (>= 1.1.1)，有一个函数 figure.tight_layout() 可以为这种情况（它是单个子图）执行边距（但不是字体大小） - 但如果您使用的是较旧的matplotlib，您可以使用figure.subplots_adjust(left=0.2, bottom=0.15, top=0.86)，这就是本示例所做的；并且已经过测试：
$ python2.7 -c 'import matplotlib; print(matplotlib.__version__)'
0.99.3
$ python3.2 -c 'import matplotlib; print(matplotlib.__version__)'
1.2.0
(我确实尝试查看是否可以为旧的 matplotlib 复制 tight_layout - 不幸的是，它需要包含在 tight_layout.py 中的一组相当复杂的函数，这反过来又要求 Figure 和 Axes 也具有特定的规范，不存在于 v.0.99)
由于subplots_adjust 采用相对参数（从 0.0 到 1.0），原则上我们可以只设置一次 - 并希望它们适用于我们所需的比例范围。其余的（字体和标签板的缩放）见下面的代码：
import math
import sys
if sys.version_info[0] < 3:
from Tkinter import Tk, Button, Frame, Canvas, Scrollbar
import Tkconstants
else:
from tkinter import Tk, Button, Frame, Canvas, Scrollbar
import tkinter.constants as Tkconstants
import matplotlib
from matplotlib import pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import pprint, inspect
frame = None
canvas = None
ax = None
def printBboxes(label=""):
global canvas, mplCanvas, interior, interior_id, cwid, figure
print(" "+label,
"canvas.bbox:", canvas.bbox(Tkconstants.ALL),
"mplCanvas.bbox:", mplCanvas.bbox(Tkconstants.ALL),
"subplotpars:", figure.subplotpars.__dict__ )
def addScrollingFigure(figure, frame):
global canvas, mplCanvas, interior, interior_id, cwid
# set up a canvas with scrollbars
canvas = Canvas(frame)
canvas.grid(row=1, column=1, sticky=Tkconstants.NSEW)
xScrollbar = Scrollbar(frame, orient=Tkconstants.HORIZONTAL)
yScrollbar = Scrollbar(frame)
xScrollbar.grid(row=2, column=1, sticky=Tkconstants.EW)
yScrollbar.grid(row=1, column=2, sticky=Tkconstants.NS)
canvas.config(xscrollcommand=xScrollbar.set)
xScrollbar.config(command=canvas.xview)
canvas.config(yscrollcommand=yScrollbar.set)
yScrollbar.config(command=canvas.yview)
# plug in the figure
figAgg = FigureCanvasTkAgg(figure, canvas)
mplCanvas = figAgg.get_tk_widget()
# and connect figure with scrolling region
cwid = canvas.create_window(0, 0, window=mplCanvas, anchor=Tkconstants.NW)
printBboxes("Init")
changeSize(figure, 1)
def changeSize(figure, factor):
global canvas, mplCanvas, interior, interior_id, frame, cwid
oldSize = figure.get_size_inches()
print("old size is", oldSize)
figure.set_size_inches([factor * s for s in oldSize])
wi,hi = [i*figure.dpi for i in figure.get_size_inches()]
print("new size is", figure.get_size_inches())
print("new size pixels: ", wi,hi)
mplCanvas.config(width=wi, height=hi) ; printBboxes("A")
canvas.itemconfigure(cwid, width=wi, height=hi) ; printBboxes("B")
canvas.config(scrollregion=canvas.bbox(Tkconstants.ALL),width=200,height=200)
tz.set_fontsize(tz.get_fontsize()*factor)
for item in ([ax.title, ax.xaxis.label, ax.yaxis.label] +
ax.get_xticklabels() + ax.get_yticklabels()):
item.set_fontsize(item.get_fontsize()*factor)
ax.xaxis.labelpad = ax.xaxis.labelpad*factor
ax.yaxis.labelpad = ax.yaxis.labelpad*factor
#figure.tight_layout() # matplotlib > 1.1.1
figure.subplots_adjust(left=0.2, bottom=0.15, top=0.86)
figure.canvas.draw() ; printBboxes("C")
print()
if __name__ == "__main__":
global root, figure
root = Tk()
root.rowconfigure(1, weight=1)
root.columnconfigure(1, weight=1)
frame = Frame(root)
frame.grid(column=1, row=1, sticky=Tkconstants.NSEW)
frame.rowconfigure(1, weight=1)
frame.columnconfigure(1, weight=1)
figure = plt.figure(dpi=150, figsize=(4, 4))
ax = figure.add_subplot(111)
ax.plot(range(10), [math.sin(x) for x in range(10)])
#tz = figure.text(0.5,0.975,'The master title',horizontalalignment='center', verticalalignment='top')
tz = figure.suptitle('The master title')
ax.set_title('Tk embedding')
ax.set_xlabel('X axis label')
ax.set_ylabel('Y label')
print(tz.get_fontsize()) # 12.0
print(ax.title.get_fontsize(), ax.xaxis.label.get_fontsize(), ax.yaxis.label.get_fontsize()) # 14.4 12.0 12.0
addScrollingFigure(figure, frame)
buttonFrame = Frame(root)
buttonFrame.grid(row=1, column=2, sticky=Tkconstants.NS)
biggerButton = Button(buttonFrame, text="larger",
command=lambda : changeSize(figure, 1.2))
biggerButton.grid(column=1, row=1)
smallerButton = Button(buttonFrame, text="smaller",
command=lambda : changeSize(figure, 0.833))
smallerButton.grid(column=1, row=2)
qButton = Button(buttonFrame, text="quit",
command=lambda : sys.exit(0))
qButton.grid(column=1, row=3)
root.mainloop()
【讨论】：
【参考方案2】：我刚刚遇到了同样的问题 - 据我所知（通过实验），除了 figure.set_size_inches()，您还必须设置 mplCanvas 的新大小以及为它创建的画布窗口的新大小，之前做figure.canvas.draw()（这也迫使一个人使用全局变量 - 或类定义）。此外，显然不需要“网格”mplCanvas - 因为它已经是 canvas 的子节点，它已经是“网格”了。并且可能想要锚定 NW，因此在每次调整大小时，绘图都会在左上角的 0,0 处重新绘制。
这对我有用（我也尝试使用 Python Tkinter scrollbar for frame 中的“内部”框架，但没有成功；其中一些留在了 sn-p 的末尾）：
import math
import sys
if sys.version_info[0] < 3:
from Tkinter import Tk, Button, Frame, Canvas, Scrollbar
import Tkconstants
else:
from tkinter import Tk, Button, Frame, Canvas, Scrollbar
import tkinter.constants as Tkconstants
from matplotlib import pyplot as plt
from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
import pprint
frame = None
canvas = None
def printBboxes(label=""):
global canvas, mplCanvas, interior, interior_id, cwid
print(" "+label,
"canvas.bbox:", canvas.bbox(Tkconstants.ALL),
"mplCanvas.bbox:", mplCanvas.bbox(Tkconstants.ALL))
def addScrollingFigure(figure, frame):
global canvas, mplCanvas, interior, interior_id, cwid
# set up a canvas with scrollbars
canvas = Canvas(frame)
canvas.grid(row=1, column=1, sticky=Tkconstants.NSEW)
xScrollbar = Scrollbar(frame, orient=Tkconstants.HORIZONTAL)
yScrollbar = Scrollbar(frame)
xScrollbar.grid(row=2, column=1, sticky=Tkconstants.EW)
yScrollbar.grid(row=1, column=2, sticky=Tkconstants.NS)
canvas.config(xscrollcommand=xScrollbar.set)
xScrollbar.config(command=canvas.xview)
canvas.config(yscrollcommand=yScrollbar.set)
yScrollbar.config(command=canvas.yview)
# plug in the figure
figAgg = FigureCanvasTkAgg(figure, canvas)
mplCanvas = figAgg.get_tk_widget()
#mplCanvas.grid(sticky=Tkconstants.NSEW)
# and connect figure with scrolling region
cwid = canvas.create_window(0, 0, window=mplCanvas, anchor=Tkconstants.NW)
printBboxes("Init")
canvas.config(scrollregion=canvas.bbox(Tkconstants.ALL),width=200,height=200)
def changeSize(figure, factor):
global canvas, mplCanvas, interior, interior_id, frame, cwid
oldSize = figure.get_size_inches()
print("old size is", oldSize)
figure.set_size_inches([factor * s for s in oldSize])
wi,hi = [i*figure.dpi for i in figure.get_size_inches()]
print("new size is", figure.get_size_inches())
print("new size pixels: ", wi,hi)
mplCanvas.config(width=wi, height=hi) ; printBboxes("A")
#mplCanvas.grid(sticky=Tkconstants.NSEW)
canvas.itemconfigure(cwid, width=wi, height=hi) ; printBboxes("B")
canvas.config(scrollregion=canvas.bbox(Tkconstants.ALL),width=200,height=200)
figure.canvas.draw() ; printBboxes("C")
print()
if __name__ == "__main__":
root = Tk()
root.rowconfigure(1, weight=1)
root.columnconfigure(1, weight=1)
frame = Frame(root)
frame.grid(column=1, row=1, sticky=Tkconstants.NSEW)
frame.rowconfigure(1, weight=1)
frame.columnconfigure(1, weight=1)
figure = plt.figure(dpi=150, figsize=(4, 4))
plt.plot(range(10), [math.sin(x) for x in range(10)])
addScrollingFigure(figure, frame)
buttonFrame = Frame(root)
buttonFrame.grid(row=1, column=2, sticky=Tkconstants.NS)
biggerButton = Button(buttonFrame, text="larger",
command=lambda : changeSize(figure, 1.5))
biggerButton.grid(column=1, row=1)
smallerButton = Button(buttonFrame, text="smaller",
command=lambda : changeSize(figure, .5))
smallerButton.grid(column=1, row=2)
root.mainloop()
"""
interior = Frame(canvas) #Frame(mplCanvas) #cannot
interior_id = canvas.create_window(0, 0, window=interior)#, anchor=Tkconstants.NW)
canvas.config(scrollregion=canvas.bbox("all"),width=200,height=200)
canvas.itemconfigure(interior_id, width=canvas.winfo_width())
interior_id = canvas.create_window(0, 0, window=interior)#, anchor=Tkconstants.NW)
canvas.config(scrollregion=canvas.bbox("all"),width=200,height=200)
canvas.itemconfigure(interior_id, width=canvas.winfo_width())
"""
一个有趣的注意是mplCanvas 会在它变大时遵守大小（如点击“更大”） - 但如果它变小则保持旧大小：
$ python2.7 test.py
(' Init', 'canvas.bbox:', (0, 0, 610, 610), 'mplCanvas.bbox:', (0, 0, 600, 600))
## here click "larger":
('old size is', array([ 4.06666667, 4.06666667]))
('new size is', array([ 6.1, 6.1]))
('new size pixels: ', 915.0, 915.0)
(' A', 'canvas.bbox:', (0, 0, 925, 925), 'mplCanvas.bbox:', (0, 0, 926, 926))
(' B', 'canvas.bbox:', (0, 0, 915, 915), 'mplCanvas.bbox:', (0, 0, 926, 926))
(' C', 'canvas.bbox:', (0, 0, 915, 915), 'mplCanvas.bbox:', (0, 0, 926, 926))
()
## here click "larger":
('old size is', array([ 6.1, 6.1]))
('new size is', array([ 9.15, 9.15]))
('new size pixels: ', 1372.4999999999998, 1372.4999999999998)
(' A', 'canvas.bbox:', (0, 0, 915, 915), 'mplCanvas.bbox:', (0, 0, 926, 926))
(' B', 'canvas.bbox:', (0, 0, 1372, 1372), 'mplCanvas.bbox:', (0, 0, 926, 926))
(' C', 'canvas.bbox:', (0, 0, 1372, 1372), 'mplCanvas.bbox:', (0, 0, 1372, 1372))
()
## here click "smaller":
('old size is', array([ 9.14666667, 9.14666667]))
('new size is', array([ 4.57333333, 4.57333333]))
('new size pixels: ', 686.0, 686.0)
(' A', 'canvas.bbox:', (0, 0, 1372, 1372), 'mplCanvas.bbox:', (0, 0, 1372, 1372))
(' B', 'canvas.bbox:', (0, 0, 686, 686), 'mplCanvas.bbox:', (0, 0, 1372, 1372))
(' C', 'canvas.bbox:', (0, 0, 686, 686), 'mplCanvas.bbox:', (0, 0, 1372, 1372))
()
在 Python3.2 中也可以看到 mplCanvas 的相同行为...不确定这是某种错误，还是我也没有正确理解 :)
另请注意，这种缩放方式不能处理轴/抽动等字体的大小调整（字体将尝试保持相同的大小）；这就是我最终可以用上面的代码得到的（截断的抽搐）：
...如果添加轴标签等，情况会变得更糟。
无论如何，希望这会有所帮助， 干杯！
【讨论】：
太好了，谢谢！不再认为有人会真正找到解决方案 - 我不得不挖掘出我废弃的旧项目来尝试这个。以上是关于如何让 Matplotlib 图形在 Tkinter GUI 中正确滚动+调整大小的主要内容，如果未能解决你的问题，请参考以下文章