Python 中数组的对数

发布于 2025-01-06 13:13:22 字数 711 浏览 4 评论 0原文

from numpy import *
from pylab import plot,show
q=10
time = range(q)
mlist=empty(q)
nlist=empty(q)
m=.9
n=(m+(1e-6))
b=3

for t in range(q):
    mlist[t]=m
    nlist[t]=n
    m=(b*(1-m)*m)
    n=(b*(1-n)*n)

zlist = mlist-nlist
zlist = abs(zlist)
plot(time, log(zlist))
show()

然后我想绘制时间图，log(zlist)

，每次运行该程序时，我都会收到此错误。 “情节（时间，日志（zlist）） TypeError: only length-1 arrays can be conversion to Python scalars"

有什么想法如何使 zlist 不是数组以便我可以获取日志，或者只是我的程序出了什么问题？其他一切都很好，只有一个问题。（仅供注意，我导入了 pylab、numpy 和 math）

编辑：q 值相对不重要，但理想情况下最终会在 500-1000 范围内。 m 和 n 必须在 0 和 1 之间，b 必须在 0 和 4 之间。

编辑 X2：它现在似乎正在工作，我不知道为什么，但它可能是 a)从数学导入日志为好吧，或者b，负值问题，但无论如何，它运行良好。感谢所有贡献者！

原文

from numpy import *
from pylab import plot,show
q=10
time = range(q)
mlist=empty(q)
nlist=empty(q)
m=.9
n=(m+(1e-6))
b=3

for t in range(q):
    mlist[t]=m
    nlist[t]=n
    m=(b*(1-m)*m)
    n=(b*(1-n)*n)

zlist = mlist-nlist
zlist = abs(zlist)
plot(time, log(zlist))
show()

then I want to plot the graph of time,log(zlist)

and everytime I run the program, i get this error.
"plot(time,log(zlist))
TypeError: only length-1 arrays can be converted to Python scalars"

Any ideas how to either make zlist not an array so I can take the log, or just what is going wrong in my program?
Everything else works well, just that one problem.
(just for note, i have imported pylab, numpy, and math)

EDIT: The q value is relatively unimportant, but ideally will eventually be up in the 500-1000 range. and m and n have to be between 0 and 1, and b has to be between 0 and 4.

EDIT X2: It seems to be working now, i'm not sure why but it could either be a)importing log from math as well, or b, the negative value problem, but regardless, it's working well. Thank you to everyone who contributed!

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

秋千易 2025-01-13 13:13:22

我怀疑您在 from numpy import * 之后执行了 from math import * ，这意味着 log 实际上是 math.log > 这不适用于数组。

您确实不应该在脚本中使用 import * 。相反，你应该做

import numpy as np
import matplotlib.pyplot as plt

q=10
time = np.arange(q)
mlist = np.empty(q)
nlist = np.empty(q)
m=.9
n=(m+(10e-6))
b=3

for t in range(q):
  mlist[t]=m
  nlist[t]=n
  m *=b*(1-m)
  n *=b*(1-n)

zlist = mlist-nlist

plt.plot(time, np.log(zlist))

或者更好

plt.semilogy(time, zlist)

I suspect that you did from math import * after from numpy import * which means that log is really math.log which won't work on an array.

You should really not use import * in scripts. Instead, you should do

import numpy as np
import matplotlib.pyplot as plt

q=10
time = np.arange(q)
mlist = np.empty(q)
nlist = np.empty(q)
m=.9
n=(m+(10e-6))
b=3

for t in range(q):
  mlist[t]=m
  nlist[t]=n
  m *=b*(1-m)
  n *=b*(1-n)

zlist = mlist-nlist

plt.plot(time, np.log(zlist))

or, better