Question

我正在学习matplotlib脚本以显示下一个情节，如果我点击下一个＆＃39;按钮。

数据是这样的：

# data.txt
10 30 21 22
12 36 22 23
13 37 23 24
14 38 24 25
15 39 25 26
16 40 26 27

要绘制的代码是：

#!python
# -*- coding: utf-8 -*-#
# Imports
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import Button

data = np.genfromtxt('data.txt')
idx = [1,2,3]

fig, ax = plt.subplots()
plt.subplots_adjust(bottom=0.2)

x = data[:,0]
y = data[:,2]

l, = plt.plot(x, y, lw=2)
colors = ['r','g','b']
linestyles = ['-','--',':']


class Index(object):
    ind = 0

    def next(self, event):
        i = self.ind % len(idx)
        ydata = data[:,idx[i]]
        l.set_ydata(ydata)
        l.set_color(colors[i])
        l.set_linestyle(linestyles[i])

        self.ind += 1
        plt.title('Plot ' + str(i))
        plt.draw()

    def prev(self, event):
        i = self.ind % len(idx)
        ydata = ydata = data[:,idx[i]]
        l.set_ydata(ydata)
        self.ind -= 1
        plt.draw()

callback = Index()
axprev = plt.axes([0.7, 0.05, 0.1, 0.075])
axnext = plt.axes([0.81, 0.05, 0.1, 0.075])
bnext = Button(axnext, 'Next')
bnext.on_clicked(callback.next)
bprev = Button(axprev, 'Previous')
bprev.on_clicked(callback.prev)

plt.show()

这里的代码适用于两个图，但是，其中一个图是空的。 y轴限制是固定的。

尝试我试过了l.set_ylim然而它失败了。

问题
a）我们如何在这个例子中显示所有的情节？ b）如何在图的顶部显示标题？它显示在底部右上角。

相关链接：
https://matplotlib.org/examples/widgets/buttons.html
https://matplotlib.org/api/_as_gen/matplotlib.lines.Line2D.html

Answer 1

a）我们如何在这个例子中显示所有图？

设置绘图的限制，以使数据在这些限制范围内ax.set_ylim(19,41)。

b）如何在图的顶部显示标题？

在绘图中创建新轴后，请勿使用plt.title。而是使用ax.set_title。

完整的工作示例：

u = u"""10 30 21 22
12 36 22 23
13 37 23 24
14 38 24 25
15 39 25 26
16 40 26 27"""

import io
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import Button

data = np.genfromtxt(io.StringIO(u))
idx = [1,2,3]

fig, ax = plt.subplots()
fig.subplots_adjust(bottom=0.2)
ax.set_ylim(19,41)

x = data[:,0]
y = data[:,1]

l, = ax.plot(x, y, lw=2)
colors = ['r','g','b']
linestyles = ['-','--',':']


class Index(object):
    ind = 0

    def next(self, event):
        self.ind += 1
        self.plot()

    def prev(self, event):
        self.ind -= 1
        self.plot()

    def plot(self):
        i = self.ind % len(idx)
        ydata = data[:,idx[i]]
        l.set_ydata(ydata)
        l.set_color(colors[i])
        l.set_linestyle(linestyles[i])
        ax.set_title('Plot ' + str(i))
        fig.canvas.draw_idle()


callback = Index()
axprev = plt.axes([0.7, 0.05, 0.1, 0.075])
axnext = plt.axes([0.81, 0.05, 0.1, 0.075])
bnext = Button(axnext, 'Next')
bnext.on_clicked(callback.next)
bprev = Button(axprev, 'Previous')
bprev.on_clicked(callback.prev)

plt.show()

Answer 2

以下是基于上述建议的更新答案。

#!python
# -*- coding: utf-8 -*-#
"""
Click next to see next plot.
"""
# Imports
import io
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import Button

def click_next(data):    
    # plot variables
    plot_nums = np.arange(1, data.shape[1])
    colors = list('rgbcmyk')*10
    linestyles = ['-','--','-.', ':', '-','--','-.']*10

    class Index(object):
        ind = 0

        def next(self, event):
            self.plot()
            self.ind += 1

        def prev(self, event):
            self.plot()
            self.ind -= 1

        def plot(self):
            i = self.ind % len(plot_nums)
            ydata = data[:,plot_nums[i]]
            l.set_ydata(ydata)
            l.set_color(colors[i])
            l.set_linestyle(linestyles[i])
            ax.set_title('Plot ' + str(i+1))
            fig.canvas.draw_idle()

    # Now plot
    fig, ax = plt.subplots()
    fig.subplots_adjust(bottom=0.2)

    # Get y limits
    ydat = data[:,1:]
    ymin = np.min(ydat,axis=0).min() -1 
    ymax = np.max(ydat,axis=0).max() +1 
    ax.set_ylim(ymin,ymax)
    print(ymin,ymax)

   # Plot first plot
    x = data[:,0]
    y = data[:,1]
    ax.set_title('Plot 1')
    l, = ax.plot(x, y, lw=2,c='r')

    # matplotlib Button
    callback = Index()
    axprev = plt.axes([0.7, 0.05, 0.1, 0.075])
    axnext = plt.axes([0.81, 0.05, 0.1, 0.075])
    bnext = Button(axnext, 'Next')
    bnext.on_clicked(callback.next)
    bprev = Button(axprev, 'Previous')
    bprev.on_clicked(callback.prev)

    # show the plot
    plt.show()

def main():
    """Run main function."""
    u = u"""
    10 10 20 30 40 50
    12 12 22 36 42 51
    13 13 23 37 43 52
    14 14 24 38 44 53
    15 15 25 39 45 54
    16 16 26 40 46 55"""
    data = np.genfromtxt(io.StringIO(u))


    click_next(data)

if __name__ == "__main__":
    main()

Maptlotlib line2d绘图set_ydata不起作用

2 个答案: