在世界地图上放大时，保持标记尺寸的扩展

Question

我刚从python开始，可能在这里有点偏离，但是我想组合这个示例“>这个解决方案，托马斯·库恩（ThomasKühn）。

下面的数据创建了带有“火球”的世界地图。问题在于，当缩放进来时，圆的大小保持不变（绝对术语），相对于背景，它们变得较小。我想将托马斯·库恩（ThomasKühn）的解决方案应用于Zack Fizell的示例（不是真正的火球，而是使用世界地图）。

问题是，当解决代码时，我几乎没有收到有用的错误消息。这使得很难弄清楚我要去哪里。

我包含了所有代码，因此当链接在某个时候死亡时，这仍然是一个有趣的问题（我只是不确定该如何处理 csv-file 需要运行示例）。

这成为一个很长的问题，但我希望这至少是一个有趣的问题。

请随时给我有关如何改进此问题的提示

示例数据如下：

# Importing libraries
import matplotlib.pyplot as plt
import pandas as pd
import geopandas as gpd

# Reading cvs file using pandas
df = pd.read_csv('cneos_fireball_data.csv', 
                 usecols=["Peak Brightness Date/Time (UT)", 
                 "Calculated Total Impact Energy (kt)", 
                 "Latitude (deg.)", "Longitude (deg.)"])
df = df.rename(columns={"Peak Brightness Date/Time (UT)": 
                        'Datetime',
                        "Calculated Total Impact Energy (kt)": 
                        'Impact Energy [kt]',
                        "Latitude (deg.)": 'Latitude',
                        "Longitude (deg.)": 'Longitude'})

# Converting to a datetime datatype
df['Datetime'] = pd.to_datetime(df['Datetime'], errors='coerce')

# Applying +/- based on direction and converting to numeric datatype
for x in range(len(df['Longitude'])):
    if str(df.loc[x, 'Longitude'])[-1] == 'E':
        df.loc[x, 'Longitude'] = str(df.loc[x, 'Longitude'])[:-1]
    if str(df.loc[x, 'Longitude'])[-1] == 'W':
        df.loc[x, 'Longitude'] = \
            '-' + str(df.loc[x, 'Longitude'])[:-1]

for x in range(len(df['Latitude'])):
    if str(df.loc[x, 'Latitude'])[-1] == 'N':
        df.loc[x, 'Latitude'] = str(df.loc[x, 'Latitude'])[:-1]
    if str(df.loc[x, 'Latitude'])[-1] == 'S':
        df.loc[x, 'Latitude'] = \
            '-' + str(df.loc[x, 'Latitude'])[:-1]

df['Longitude'] = pd.to_numeric(df['Longitude'], errors='coerce')
df['Latitude'] = pd.to_numeric(df['Latitude'], errors='coerce')

# Converting to numeric datatype
threshold = 20
df = df[df['Impact Energy [kt]'] < threshold]
df['Impact Energy [kt]'] = pd.to_numeric(df['Impact Energy [kt]'], 
                                         errors='coerce')

# Dropping the errors from data conversions and resetting index
df.dropna()
df = df.reset_index(drop=True)

# From GeoPandas, our world map data
worldmap = gpd.read_file(gpd.datasets.get_path("naturalearth_lowres"))

# Creating axes and plotting world map
fig, ax = plt.subplots(figsize=(12, 6))
worldmap.plot(color="lightgrey", ax=ax)

# Plotting our Impact Energy data with a color map
x = df['Longitude']
y = df['Latitude']
z = df['Impact Energy [kt]']
plt.scatter(x, y, s=20*z, c=z, alpha=0.6, vmin=0, vmax=threshold,
            cmap='autumn')
plt.colorbar(label='Impact Energy [kt]')

# Creating axis limits and title
plt.xlim([-180, 180])
plt.ylim([-90, 90])

first_year = df["Datetime"].min().strftime("%Y")
last_year = df["Datetime"].max().strftime("%Y")
plt.title("NASA: Fireballs Reported by Government Sensors\n" +     
          str(first_year) + " - " + str(last_year))
plt.xlabel("Longitude")
plt.ylabel("Latitude")
plt.show()

<

a href =“ https://i.sstatic.net/sihgw.png” rel = “ nofollow noreferrer”>

我的重点是我在适应解决方案时遇到了麻烦。主要是因为我不太了解MarkerupDater类非常好（见下文）。

库恩（

from matplotlib import pyplot as plt
import numpy as np

##plt.switch_backend('TkAgg')
class MarkerUpdater:
    def __init__(self):
        ##for storing information about Figures and Axes
        self.figs = {}

        ##for storing timers
        self.timer_dict = {}

    def add_ax(self, ax, features=[]):
        ax_dict = self.figs.setdefault(ax.figure,dict())
        ax_dict[ax] = {
            'xlim' : ax.get_xlim(),
            'ylim' : ax.get_ylim(),
            'figw' : ax.figure.get_figwidth(),
            'figh' : ax.figure.get_figheight(),
            'scale_s' : 1.0,
            'scale_a' : 1.0,
            'features' : [features] if isinstance(features,str) else features,
        }
        ax.figure.canvas.mpl_connect('draw_event', self.update_axes)

    def update_axes(self, event):

        for fig,axes in self.figs.items():
            if fig is event.canvas.figure:

                for ax, args in axes.items():
                    ##make sure the figure is re-drawn
                    update = True

                    fw = fig.get_figwidth()
                    fh = fig.get_figheight()
                    fac1 = min(fw/args['figw'], fh/args['figh'])


                    xl = ax.get_xlim()
                    yl = ax.get_ylim()
                    fac2 = min(
                        abs(args['xlim'][1]-args['xlim'][0])/abs(xl[1]-xl[0]),
                        abs(args['ylim'][1]-args['ylim'][0])/abs(yl[1]-yl[0])
                    )

                    ##factor for marker size
                    facS = (fac1*fac2)/args['scale_s']

                    ##factor for alpha -- limited to values smaller 1.0
                    facA = min(1.0,fac1*fac2)/args['scale_a']

                    ##updating the artists
                    if facS != 1.0:
                        for line in ax.lines:
                            if 'size' in args['features']:
                                line.set_markersize(line.get_markersize()*facS)

                            if 'alpha' in args['features']:
                                alpha = line.get_alpha()
                                if alpha is not None:
                                    line.set_alpha(alpha*facA)


                        for path in ax.collections:
                            if 'size' in args['features']:
                                path.set_sizes([s*facS**2 for s in path.get_sizes()])

                            if 'alpha' in args['features']:
                                alpha = path.get_alpha()
                                if alpha is not None:
                                    path.set_alpha(alpha*facA)

                        args['scale_s'] *= facS
                        args['scale_a'] *= facA

                self._redraw_later(fig)



    def _redraw_later(self, fig):
        timer = fig.canvas.new_timer(interval=10)
        timer.single_shot = True
        timer.add_callback(lambda : fig.canvas.draw_idle())
        timer.start()

        ##stopping previous timer
        if fig in self.timer_dict:
            self.timer_dict[fig].stop()

        ##storing a reference to prevent garbage collection
        self.timer_dict[fig] = timer

if __name__ == '__main__':
    my_updater = MarkerUpdater()

    ##setting up the figure
    fig, axes = plt.subplots(nrows = 2, ncols =2)#, figsize=(1,1))
    ax1,ax2,ax3,ax4 = axes.flatten()

    ## a line plot
    x1 = np.linspace(0,np.pi,30)
    y1 = np.sin(x1)
    ax1.plot(x1, y1, 'ro', markersize = 10, alpha = 0.8)
    ax3.plot(x1, y1, 'ro', markersize = 10, alpha = 1)

    ## a scatter plot
    x2 = np.random.normal(1,1,30)
    y2 = np.random.normal(1,1,30)
    ax2.scatter(x2,y2, c = 'b', s = 100, alpha = 0.6)

    ## scatter and line plot
    ax4.scatter(x2,y2, c = 'b', s = 100, alpha = 0.6)
    ax4.plot([0,0.5,1],[0,0.5,1],'ro', markersize = 10) ##note: no alpha value!

    ##setting up the updater
    my_updater.add_ax(ax1, ['size'])  ##line plot, only marker size
    my_updater.add_ax(ax2, ['size'])  ##scatter plot, only marker size
    my_updater.add_ax(ax3, ['alpha']) ##line plot, only alpha
    my_updater.add_ax(ax4, ['size', 'alpha']) ##scatter plot, marker size and alpha

    plt.show()

ThomasKühn

托马斯· “ alt =”在此处输入图像描述”>

我的尝试

请注意：我没有触摸MarketUpdater，我只使用Thomas的解决方案的ax2 ：

from matplotlib import pyplot as plt
import numpy as np

##plt.switch_backend('TkAgg')
class MarkerUpdater:
    def __init__(self):
        ##for storing information about Figures and Axes
        self.figs = {}

        ##for storing timers
        self.timer_dict = {}

    def add_ax(self, ax, features=[]):
        ax_dict = self.figs.setdefault(ax.figure,dict())
        ax_dict[ax] = {
            'xlim' : ax.get_xlim(),
            'ylim' : ax.get_ylim(),
            'figw' : ax.figure.get_figwidth(),
            'figh' : ax.figure.get_figheight(),
            'scale_s' : 1.0,
            'scale_a' : 1.0,
            'features' : [features] if isinstance(features,str) else features,
        }
        ax.figure.canvas.mpl_connect('draw_event', self.update_axes)

    def update_axes(self, event):

        for fig,axes in self.figs.items():
            if fig is event.canvas.figure:

                for ax, args in axes.items():
                    ##make sure the figure is re-drawn
                    update = True

                    fw = fig.get_figwidth()
                    fh = fig.get_figheight()
                    fac1 = min(fw/args['figw'], fh/args['figh'])


                    xl = ax.get_xlim()
                    yl = ax.get_ylim()
                    fac2 = min(
                        abs(args['xlim'][1]-args['xlim'][0])/abs(xl[1]-xl[0]),
                        abs(args['ylim'][1]-args['ylim'][0])/abs(yl[1]-yl[0])
                    )

                    ##factor for marker size
                    facS = (fac1*fac2)/args['scale_s']

                    ##factor for alpha -- limited to values smaller 1.0
                    facA = min(1.0,fac1*fac2)/args['scale_a']

                    ##updating the artists
                    if facS != 1.0:
                        for line in ax.lines:
                            if 'size' in args['features']:
                                line.set_markersize(line.get_markersize()*facS)

                            if 'alpha' in args['features']:
                                alpha = line.get_alpha()
                                if alpha is not None:
                                    line.set_alpha(alpha*facA)


                        for path in ax.collections:
                            if 'size' in args['features']:
                                path.set_sizes([s*facS**2 for s in path.get_sizes()])

                            if 'alpha' in args['features']:
                                alpha = path.get_alpha()
                                if alpha is not None:
                                    path.set_alpha(alpha*facA)

                        args['scale_s'] *= facS
                        args['scale_a'] *= facA

                self._redraw_later(fig)



    def _redraw_later(self, fig):
        timer = fig.canvas.new_timer(interval=10)
        timer.single_shot = True
        timer.add_callback(lambda : fig.canvas.draw_idle())
        timer.start()

        ##stopping previous timer
        if fig in self.timer_dict:
            self.timer_dict[fig].stop()

        ##storing a reference to prevent garbage collection
        self.timer_dict[fig] = timer

if __name__ == '__main__':
    my_updater = MarkerUpdater()

    ##setting up the figure
    fig, axes = plt.subplots(nrows=2, ncols=3,figsize=(12, 6)) # swatchai's comment
    ax2 = axes.flatten()

    ## a line plot
    # x1 = np.linspace(0,np.pi,30)
    # y1 = np.sin(x1)
    # ax1.plot(x1, y1, 'ro', markersize = 10, alpha = 0.8)
    # ax3.plot(x1, y1, 'ro', markersize = 10, alpha = 1)

    ## a scatter plot
    worldmap.plot(color="lightgrey", ax=ax2)

    # Plotting our Impact Energy data with a color map
    x = df['Longitude']
    y = df['Latitude']
    z = df['Impact Energy [kt]']
    # x = np.random.normal(1,1,30)
    # y = np.random.normal(1,1,30)
    ax2.scatter(x, y, s=20*z, c=z, alpha=0.6, vmin=0, vmax=threshold,
        cmap='autumn')

    ## scatter and line plot
    # ax4.scatter(x2,y2, c = 'b', s = 100, alpha = 0.6)
    # ax4.plot([0,0.5,1],[0,0.5,1],'ro', markersize = 10) ##note: no alpha value!

    ##setting up the updater
    # my_updater.add_ax(ax1, ['size'])  ##line plot, only marker size
    my_updater.add_ax(ax2, ['size'])  ##scatter plot, only marker size
    # my_updater.add_ax(ax3, ['alpha']) ##line plot, only alpha
    # my_updater.add_ax(ax4, ['size', 'alpha']) ##scatter plot, marker size and alpha

    plt.show()

追溯

错误是在此行中的错误：

worldmap.plot(color="lightgrey", ax=ax2)

Trackback：

Traceback (most recent call last):
  File "c:\Users\x\OneDrive - Wageningen University & Research\Arjen Daane\Data\tempCodeRunnerFile.python", line 185, in <module>
    worldmap.plot(color="lightgrey", ax=ax2)
  File "C:\Users\x\AppData\Local\Programs\Python\Python310\lib\site-packages\geopandas\geodataframe.py", line 617, in plot
    return plot_dataframe(self, *args, **kwargs)
  File "C:\Users\x\AppData\Local\Programs\Python\Python310\lib\site-packages\geopandas\plotting.py", line 504, in plot_dataframe
    ax.set_aspect("equal")
AttributeError: 'numpy.ndarray' object has no attribute 'set_aspect'

有人有兴趣帮助我前进吗？

Answer 1

问题在于，MarkerupDater对象也试图重建世界地图本身。您可以通过在避免重新缩放的课堂中添加IF语句来避免这种情况。还为此解决方案添加额外的导入列表：

import matplotlib.pyplot as plt
## UPDATE: Add this import: #########################################
from matplotlib.collections import PatchCollection
import pandas as pd

##plt.switch_backend('TkAgg')
class MarkerUpdater:
    def __init__(self):
        ##for storing information about Figures and Axes
        self.figs = {}

        ##for storing timers
        self.timer_dict = {}

    def add_ax(self, ax, features=[]):
        ax_dict = self.figs.setdefault(ax.figure,dict())
        ax_dict[ax] = {
            'xlim' : ax.get_xlim(),
            'ylim' : ax.get_ylim(),
            'figw' : ax.figure.get_figwidth(),
            'figh' : ax.figure.get_figheight(),
            'scale_s' : 1.0,
            'scale_a' : 1.0,
            'features' : [features] if isinstance(features,str) else features,
        }
        ax.figure.canvas.mpl_connect('draw_event', self.update_axes)

    def update_axes(self, event):

        for fig,axes in self.figs.items():
            if fig is event.canvas.figure:

                for ax, args in axes.items():
                    ##make sure the figure is re-drawn
                    update = True

                    fw = fig.get_figwidth()
                    fh = fig.get_figheight()
                    fac1 = min(fw/args['figw'], fh/args['figh'])


                    xl = ax.get_xlim()
                    yl = ax.get_ylim()
                    fac2 = min(
                        abs(args['xlim'][1]-args['xlim'][0])/abs(xl[1]-xl[0]),
                        abs(args['ylim'][1]-args['ylim'][0])/abs(yl[1]-yl[0])
                    )

                    ##factor for marker size
                    facS = (fac1*fac2)/args['scale_s']

                    ##factor for alpha -- limited to values smaller 1.0
                    facA = min(1.0,fac1*fac2)/args['scale_a']

                    ##updating the artists
                    if facS != 1.0:
                        for line in ax.lines:
                            if 'size' in args['features']:
                                line.set_markersize(line.get_markersize()*facS)

                            if 'alpha' in args['features']:
                                alpha = line.get_alpha()
                                if alpha is not None:
                                    line.set_alpha(alpha*facA)


                        for path in ax.collections:
                            if 'size' in args['features']:
############################### UPDATE: Add this if statement: ########################
                                if not isinstance(path, PatchCollection):   
                                    path.set_sizes([s*facS**2 for s in path.get_sizes()])

                            if 'alpha' in args['features']:
                                alpha = path.get_alpha()
                                if alpha is not None:
                                    path.set_alpha(alpha*facA)

                        args['scale_s'] *= facS
                        args['scale_a'] *= facA

                self._redraw_later(fig)



    def _redraw_later(self, fig):
        timer = fig.canvas.new_timer(interval=10)
        timer.single_shot = True
        timer.add_callback(lambda : fig.canvas.draw_idle())
        timer.start()

        ##stopping previous timer
        if fig in self.timer_dict:
            self.timer_dict[fig].stop()

        ##storing a reference to prevent garbage collection
        self.timer_dict[fig] = timer

                            if 'alpha' in args['features']:
                                alpha = path.get_alpha()
                                if alpha is not None:
                                    path.set_alpha(alpha*facA)

                        args['scale_s'] *= facS
                        args['scale_a'] *= facA

                self._redraw_later(fig)



    def _redraw_later(self, fig):
        timer = fig.canvas.new_timer(interval=10)
        timer.single_shot = True
        timer.add_callback(lambda : fig.canvas.draw_idle())
        timer.start()

        ##stopping previous timer
        if fig in self.timer_dict:
            self.timer_dict[fig].stop()

        ##storing a reference to prevent garbage collection
        self.timer_dict[fig] = timer

那么您的代码应该看起来像这样：

...

## UPDATE: construct the object
my_updater = MarkerUpdater()

# Creating axes and plotting world map
fig, ax = plt.subplots(figsize=(12, 6))
worldmap.plot(color="lightgrey", ax=ax)

# Plotting our Impact Energy data with a color map
x = df['Longitude']
y = df['Latitude']
z = df['Impact Energy [kt]']
plt.scatter(x, y, s=20*z, c=z, alpha=0.6, vmin=0, vmax=threshold,
            cmap='autumn')
plt.colorbar(label='Impact Energy [kt]')

## UPDATE: Link the scatter plot to the object
my_updater.add_ax(ax, ['size'])  ##line plot, only marker size

...

好运！