如何使Matplotlib图形在Tkinter GUI中正确滚动调整大小

Question

我有一个Tkinter GUI，它显示Matplotlib绘图（Python 2.7.3和Matplotlib 1.2.0rc2），并允许用户配置绘图的某些方面。绘图趋向于变大，因此图形被包装在滚动画布中。配置绘图的一个方面是更改其大小。

现在，虽然绘图一方面可以正常滚动，另一方面也可以调整大小，但这两个操作不能结合使用。下面是演示效果的脚本。（对不起，长度太长了，我不能再短了。）你可以在绘图中滚动（使用滚动条），也可以使绘图变得越来越小（使用按钮）。但是，无论何时滚动，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()

我想我遗漏了一些关于情节是如何发展的

那么，有没有人对调整大小操作后如何让这些滚动条正常运行有任何想法？

Answer 1

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（），您还必须为它设置新的mplCanvas和画布创建的窗口的大小，在执行figure.canvas.draw（）（然后还强制使用全局vars-或类定义）之前。此外，显然不需要网格mplCanvas，因为它已经是画布的孩子，这已经是网格。可能想锚定西北，所以在每次调整大小时，情节会在左上角的0.0处重新绘制。

以下是对我有效的方法（我也尝试过使用“内部”框架，如Python Tkinter scrollbar for frame中的方法，但不起作用；有些方法留在代码段的末尾）：

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())
"""

一个有趣的注意事项是，mplCanvas将服从大小，如果它变得更大（如单击更大）-但保持旧的大小，如果它变得更小：

$ 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))
()

同样的行为mplCanvas可以在Python3.2中看到，以及...不确定这是否是一种错误，或者我也不理解正确的东西

还请注意，这种方式的缩放不会处理轴/tics等字体的大小调整（字体将尝试保持相同的大小）；这就是我最终可以通过上面的代码得到的（截短的tics）：

...如果你添加轴标签，情况会变得更糟。

无论如何，希望这有帮助，
干杯！

Answer 2

对；在这个答案中的滚动条讨论之后，我最终经历了这个：

• 如何在Matplotlib中设置地物标题和轴标签的字体大小？

...我想我设法得到了一种缩放代码，它也缩放（某种程度上）标签和填充，所以（大约）整个情节适合内部（注意，第二张图片使用imgur的“中等”缩放）：

对于非常小的尺寸，标签再次开始消失-但它仍然适用于各种尺寸。

请注意，对于较新的matplotlib(

$ python2.7 -c 'import matplotlib; print(matplotlib.__version__)'
0.99.3
$ python3.2 -c 'import matplotlib; print(matplotlib.__version__)'
1.2.0

（我确实试着看看是否可以为较旧的matplotlib复制tight_layout——不幸的是，它需要tight_layout.py中包含的一组相当复杂的函数，而tight_layout.py反过来又要求图形和轴也有特定的规范，v.0.99中没有）

由于subplot\u adjust采用了相关参数（从0.0到1.0），因此原则上我们只需设置一次，并希望它们能保持我们所需的比例范围。其余部分（字体和labelpad的缩放）请参见下面的代码：

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()