python - Matplotlib NavigationToolbar : Advanced figure options?

Question

我在 GUI 应用程序中使用 matplotlib 和 PyQt5。为了绘制我的数据，我使用“FigureCanvasQTAgg”并添加“NavigationToolbar2QT”以便能够修改和保存我的绘图。它有效，但我想知道是否有更多先进的工具栏，例如允许更改标题和/或标签的字体大小？这是我使用的 atm:

import matplotlib.pyplot as plt
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg as FigureCanvas
from matplotlib.backends.backend_qt5agg import NavigationToolbar2QT as NavigationToolbar

self.figure = plt.figure()
self.ax = self.figure.add_subplot(111)
self.canvas = FigureCanvas(self.figure)
self.toolbar = NavigationToolbar(self.canvas)

可用的“图形选项”如下所示:

我正在寻找的选项是:

• 标题的字体大小
• 轴标签的字体大小
• 图例选项，如位置、字体大小、样式

可能我不是第一个寻找这些选项的人，所以我想有人已经编写了这样一个高级工具栏的代码，但我找不到任何东西，并且认为在我尝试自己编写代码之前值得在这里询问并且(可能)浪费了很多时间。

Answer 1

图形选项qt对话框定义在 https://github.com/matplotlib/matplotlib/blob/master/lib/matplotlib/backends/qt_editor/figureoptions.py

您可以将该代码复制到一个新文件中，比如 myfigureoptions.py 并进行您想要的更改。然后猴子将其修补成原来的样子。

下面将添加一个标题字体大小字段。

# Copyright © 2009 Pierre Raybaut
# Licensed under the terms of the MIT License
# see the mpl licenses directory for a copy of the license
# Modified to add a title fontsize 

"""Module that provides a GUI-based editor for matplotlib's figure options."""

import os.path
import re

import matplotlib
from matplotlib import cm, colors as mcolors, markers, image as mimage
import matplotlib.backends.qt_editor.formlayout as formlayout
from matplotlib.backends.qt_compat import QtGui



def get_icon(name):
    basedir = os.path.join(matplotlib.rcParams['datapath'], 'images')
    return QtGui.QIcon(os.path.join(basedir, name))


LINESTYLES = {'-': 'Solid',
              '--': 'Dashed',
              '-.': 'DashDot',
              ':': 'Dotted',
              'None': 'None',
              }

DRAWSTYLES = {
    'default': 'Default',
    'steps-pre': 'Steps (Pre)', 'steps': 'Steps (Pre)',
    'steps-mid': 'Steps (Mid)',
    'steps-post': 'Steps (Post)'}

MARKERS = markers.MarkerStyle.markers


def figure_edit(axes, parent=None):
    """Edit matplotlib figure options"""
    sep = (None, None)  # separator

    # Get / General
    # Cast to builtin floats as they have nicer reprs.
    xmin, xmax = map(float, axes.get_xlim())
    ymin, ymax = map(float, axes.get_ylim())
    general = [('Title', axes.get_title()),
               ('Title Fontsize', axes.title.get_fontsize()),  # <------------- HERE
               sep,
               (None, "<b>X-Axis</b>"),
               ('Left', xmin), ('Right', xmax),
               ('Label', axes.get_xlabel()),
               ('Scale', [axes.get_xscale(), 'linear', 'log', 'logit']),
               sep,
               (None, "<b>Y-Axis</b>"),
               ('Bottom', ymin), ('Top', ymax),
               ('Label', axes.get_ylabel()),
               ('Scale', [axes.get_yscale(), 'linear', 'log', 'logit']),
               sep,
               ('(Re-)Generate automatic legend', False),
               ]

    # Save the unit data
    xconverter = axes.xaxis.converter
    yconverter = axes.yaxis.converter
    xunits = axes.xaxis.get_units()
    yunits = axes.yaxis.get_units()

    # Sorting for default labels (_lineXXX, _imageXXX).
    def cmp_key(label):
        match = re.match(r"(_line|_image)(\d+)", label)
        if match:
            return match.group(1), int(match.group(2))
        else:
            return label, 0

    # Get / Curves
    linedict = {}
    for line in axes.get_lines():
        label = line.get_label()
        if label == '_nolegend_':
            continue
        linedict[label] = line
    curves = []

    def prepare_data(d, init):
        """Prepare entry for FormLayout.

        `d` is a mapping of shorthands to style names (a single style may
        have multiple shorthands, in particular the shorthands `None`,
        `"None"`, `"none"` and `""` are synonyms); `init` is one shorthand
        of the initial style.

        This function returns an list suitable for initializing a
        FormLayout combobox, namely `[initial_name, (shorthand,
        style_name), (shorthand, style_name), ...]`.
        """
        if init not in d:
            d = {**d, init: str(init)}
        # Drop duplicate shorthands from dict (by overwriting them during
        # the dict comprehension).
        name2short = {name: short for short, name in d.items()}
        # Convert back to {shorthand: name}.
        short2name = {short: name for name, short in name2short.items()}
        # Find the kept shorthand for the style specified by init.
        canonical_init = name2short[d[init]]
        # Sort by representation and prepend the initial value.
        return ([canonical_init] +
                sorted(short2name.items(),
                       key=lambda short_and_name: short_and_name[1]))

    curvelabels = sorted(linedict, key=cmp_key)
    for label in curvelabels:
        line = linedict[label]
        color = mcolors.to_hex(
            mcolors.to_rgba(line.get_color(), line.get_alpha()),
            keep_alpha=True)
        ec = mcolors.to_hex(
            mcolors.to_rgba(line.get_markeredgecolor(), line.get_alpha()),
            keep_alpha=True)
        fc = mcolors.to_hex(
            mcolors.to_rgba(line.get_markerfacecolor(), line.get_alpha()),
            keep_alpha=True)
        curvedata = [
            ('Label', label),
            sep,
            (None, '<b>Line</b>'),
            ('Line style', prepare_data(LINESTYLES, line.get_linestyle())),
            ('Draw style', prepare_data(DRAWSTYLES, line.get_drawstyle())),
            ('Width', line.get_linewidth()),
            ('Color (RGBA)', color),
            sep,
            (None, '<b>Marker</b>'),
            ('Style', prepare_data(MARKERS, line.get_marker())),
            ('Size', line.get_markersize()),
            ('Face color (RGBA)', fc),
            ('Edge color (RGBA)', ec)]
        curves.append([curvedata, label, ""])
    # Is there a curve displayed?
    has_curve = bool(curves)

    # Get / Images
    imagedict = {}
    for image in axes.get_images():
        label = image.get_label()
        if label == '_nolegend_':
            continue
        imagedict[label] = image
    imagelabels = sorted(imagedict, key=cmp_key)
    images = []
    cmaps = [(cmap, name) for name, cmap in sorted(cm.cmap_d.items())]
    for label in imagelabels:
        image = imagedict[label]
        cmap = image.get_cmap()
        if cmap not in cm.cmap_d.values():
            cmaps = [(cmap, cmap.name)] + cmaps
        low, high = image.get_clim()
        imagedata = [
            ('Label', label),
            ('Colormap', [cmap.name] + cmaps),
            ('Min. value', low),
            ('Max. value', high),
            ('Interpolation',
             [image.get_interpolation()]
             + [(name, name) for name in sorted(mimage.interpolations_names)])]
        images.append([imagedata, label, ""])
    # Is there an image displayed?
    has_image = bool(images)

    datalist = [(general, "Axes", "")]
    if curves:
        datalist.append((curves, "Curves", ""))
    if images:
        datalist.append((images, "Images", ""))

    def apply_callback(data):
        """This function will be called to apply changes"""
        orig_xlim = axes.get_xlim()
        orig_ylim = axes.get_ylim()

        general = data.pop(0)
        curves = data.pop(0) if has_curve else []
        images = data.pop(0) if has_image else []
        if data:
            raise ValueError("Unexpected field")
        # Set / General
        (title, titlefontsize, xmin, xmax, xlabel, xscale,    # <------------- HERE
         ymin, ymax, ylabel, yscale, generate_legend) = general 

        if axes.get_xscale() != xscale:
            axes.set_xscale(xscale)
        if axes.get_yscale() != yscale:
            axes.set_yscale(yscale)

        axes.set_title(title)
        axes.title.set_fontsize(titlefontsize)                # <------------- HERE
        axes.set_xlim(xmin, xmax)
        axes.set_xlabel(xlabel)
        axes.set_ylim(ymin, ymax)
        axes.set_ylabel(ylabel)

        # Restore the unit data
        axes.xaxis.converter = xconverter
        axes.yaxis.converter = yconverter
        axes.xaxis.set_units(xunits)
        axes.yaxis.set_units(yunits)
        axes.xaxis._update_axisinfo()
        axes.yaxis._update_axisinfo()

        # Set / Curves
        for index, curve in enumerate(curves):
            line = linedict[curvelabels[index]]
            (label, linestyle, drawstyle, linewidth, color, marker, markersize,
             markerfacecolor, markeredgecolor) = curve
            line.set_label(label)
            line.set_linestyle(linestyle)
            line.set_drawstyle(drawstyle)
            line.set_linewidth(linewidth)
            rgba = mcolors.to_rgba(color)
            line.set_alpha(None)
            line.set_color(rgba)
            if marker is not 'none':
                line.set_marker(marker)
                line.set_markersize(markersize)
                line.set_markerfacecolor(markerfacecolor)
                line.set_markeredgecolor(markeredgecolor)

        # Set / Images
        for index, image_settings in enumerate(images):
            image = imagedict[imagelabels[index]]
            label, cmap, low, high, interpolation = image_settings
            image.set_label(label)
            image.set_cmap(cm.get_cmap(cmap))
            image.set_clim(*sorted([low, high]))
            image.set_interpolation(interpolation)

        # re-generate legend, if checkbox is checked
        if generate_legend:
            draggable = None
            ncol = 1
            if axes.legend_ is not None:
                old_legend = axes.get_legend()
                draggable = old_legend._draggable is not None
                ncol = old_legend._ncol
            new_legend = axes.legend(ncol=ncol)
            if new_legend:
                new_legend.set_draggable(draggable)

        # Redraw
        figure = axes.get_figure()
        figure.canvas.draw()
        if not (axes.get_xlim() == orig_xlim and axes.get_ylim() == orig_ylim):
            figure.canvas.toolbar.push_current()

    data = formlayout.fedit(datalist, title="Figure options", parent=parent,
                            icon=get_icon('qt4_editor_options.svg'),
                            apply=apply_callback)
    if data is not None:
        apply_callback(data)

# Monkey-patch original figureoptions    
from matplotlib.backends.qt_editor import figureoptions       # <------------- HERE
figureoptions.figure_edit = figure_edit

用作

import matplotlib.pyplot as plt
import myfigureoptions

fig, ax = plt.subplots()
ax.plot([1,2])
ax.set_title("My Title")

plt.show()

单击图形选项对话框时，您现在有一个标题字体大小字段。