使用 matplotlib 生成交互式绘图时的图形问题

Question

我试图用滑块制作交互式绘图。 但是当我移动滑块时，图表的峰值高度不再变为 1。 根据 Desmos，图表应该是这样的： Graph of the function

不改变峰高，只有当余弦内的值发生变化时，峰的 x 值才会发生变化。 图的编码有问题吗？因为功能比较复杂。

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import Slider, Button, RadioButtons

fig, ax = plt.subplots()
ax.set_ylabel("L")
ax.set_xlabel("Energy in keV")
ax.set_title("Output graph for change of spectrum with the detection angle")
plt.subplots_adjust(left=0.25, bottom=0.25)
t = np.arange(10, 20.0, 0.01)
a0 = 0
s = 0.01/(0.01+2*np.power(((1/((1/t)-((1-np.cos(a0)))/512))-17),2))
l, = plt.plot(t, s, lw=2)
ax.margins(x=0)
axcolor = 'lightgoldenrodyellow'
axamp = plt.axes([0.25, 0.09, 0.65, 0.03], facecolor=axcolor)

samp = Slider(axamp, 'Detection angle',0.0, 180.0,valstep=5, valinit=a0)

def update(val):
    amp = samp.val
    l.set_ydata(0.1/(0.1+2*np.power(((1/((1/t)-(1-np.cos(amp))/512))-17),2)))
    fig.canvas.draw_idle()

samp.on_changed(update)

resetax = plt.axes([0.8, 0.025, 0.1, 0.04])
button = Button(resetax, 'Reset', color=axcolor, hovercolor='0.975')


def reset(event):
    samp.reset()
button.on_clicked(reset)

rax = plt.axes([0.025, 0.5, 0.13, 0.15], facecolor=axcolor)
radio = RadioButtons(rax, ('red', 'blue', 'green'), active=0)


def colorfunc(label):
    l.set_color(label)
    fig.canvas.draw_idle()
radio.on_clicked(colorfunc)

colorfunc(radio.value_selected)

plt.show()

我对 Python 编程很陌生，如果有任何错误，请原谅我。 谢谢。

Answer 1

将np.cos(amp) 更改为np.cos(np.deg2rad(amp))（这是因为，np.cos 需要以弧度为单位的输入角度）

另外，我认为你应该在基于你在帖子中链接到的图像计算公式中的(1/t) 之后有一个+。

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.widgets import Slider, Button, RadioButtons

fig, ax = plt.subplots()
ax.set_ylabel("L")
ax.set_xlabel("Energy in keV")
ax.set_title("Output graph for change of spectrum with the detection angle")
plt.subplots_adjust(left=0.25, bottom=0.25)
t = np.arange(10, 20.0, 0.01)
a0 = 0
# 0 radians or 0 degress doesn't matter so you can neglect conversion here
s = 0.01 / (0.01 + 2 * np.power(((1 / ((1 / t) + ((1 - np.cos(a0))) / 512)) - 17), 2))
l, = plt.plot(t, s, lw=2)
ax.margins(x=0)
axcolor = 'lightgoldenrodyellow'
axamp = plt.axes([0.25, 0.09, 0.65, 0.03], facecolor=axcolor)

samp = Slider(axamp, 'Detection angle', 0.0, 180.0, valstep=5, valinit=a0)


def update(val):
    amp = samp.val
    l.set_ydata(0.1 / (0.1 + 2 * np.power(((1 / ((1 / t) + (1 - np.cos(np.deg2rad(amp))) / 512)) - 17), 2)))
    fig.canvas.draw_idle()


samp.on_changed(update)

resetax = plt.axes([0.8, 0.025, 0.1, 0.04])
button = Button(resetax, 'Reset', color=axcolor, hovercolor='0.975')


def reset(event):
    samp.reset()


button.on_clicked(reset)

rax = plt.axes([0.025, 0.5, 0.13, 0.15], facecolor=axcolor)
radio = RadioButtons(rax, ('red', 'blue', 'green'), active=0)


def colorfunc(label):
    l.set_color(label)
    fig.canvas.draw_idle()


radio.on_clicked(colorfunc)

colorfunc(radio.value_selected)

plt.show()