NaN处理 [英] NaN handling
问题描述
亲爱的蟒蛇专家，
我是python和这个网站的新手，所以如果这不是主题，我会道歉（即它是一个SciPy问题吗？）。我将尝试在下面演示我的问题：
--------------------------------- -----------------------
＃！/ usr / local / bin / python
来自scipy import *
来自scipy.stats import *
a = norm（loc = 0，scale = 1）
a_data = a.rvs（10）
问题=零（10）
打印问题
h_x1_x2 = -sum （问题* log2（a_data））
打印h_x1_x2
#NNN
---------- ------------------------------------------------ <无线电通信/>
我需要一种处理NaN的方法，例如R有''na.omit''选项。有人知道这是否存在吗？
非常感谢
Andy
2006-05-03，Andy McDonagh< an ********** @ earthlink.net>写道：亲爱的python专家，
我是python和这个网站的新手，所以如果这不是主题，我道歉（即它是一个SciPy问题吗？）。我将尝试在下面展示我的问题：
------------------------------------- -------------------
＃！/ usr / local / bin / python
来自scipy import *
来自scipy.stats导入*
a = norm（loc = 0，scale = 1）
a_data = a.rvs（10）
问题=零（10）打印问题
h_x1_x2 = -sum（问题* log2（a_data））
打印h_x1_x2
#NNN
------- -------------------------------------------------- -
我需要一种处理NaNs的方式
处理NaNs。
显然他们不是处理你想要的方式？
例如R有''na.omit''选项。有没有人知道这是否存在？
如果你解释你想要如何处理NaN会有所帮助，但是我会b / b
don不记得那些是任何选项。处理NaNs
除了scipy的默认方式。
-
Grant Edwards grante哇！这是没有用的......我已经去了CLUB MED了
!!
visi.com
< snip>
NaN被处理。
抛出异常会很好常规Python（非scipy）。
这可以在OSX和Linux上捕获NaN：
＃假设x是一个数字
如果x + 1 == x或x！= x：
#x是NaN
但作为预防措施是昂贵的。
Assert可用于测试，如果生产代码可以用-0
或-OO运行。
< blockquote> 2006-05-05，Ivan Vinogradov< vi ***** @ mcmaster.ca>写道：
< snip>
NaNs被处理。
在常规Python（非scipy）中抛出异常会很好。
这会破坏我的大多数Python程序（至少大部分是我做浮点数的
）。我的主要问题是
NaNs（和Infs）是没有字符串表示
在各个平台上是一致的。
这个有效在OSX和Linux上捕获NaN：
＃假设x是一个数字
如果x + 1 == x或x！= x：
#x是NaN
但作为预防措施是昂贵的。断言可以用于测试，如果生产代码可以用-0或
-OO运行。
有我们这些人在生产代码中需要NaNs，所以它必须是可以配置的
。我发现
在我的程序中我需要做某事的地方
例外 NaN非常有限。绝大多数时候，我需要他们悄悄地宣传。
-
格兰特爱德华兹格兰特哇！平民数千天
...已经制作了
visi.com ...感觉
美学模块 -
Dear python experts,
I am new to python and this site, so I apologize if this is off topic (i.e. is it a SciPy question?). I will try to demonstrate my problem below:
--------------------------------------------------------
#!/usr/local/bin/python
from scipy import *
from scipy.stats import *
a=norm(loc=0,scale=1)
a_data = a.rvs(10)
problem = zeros(10)
print problem
h_x1_x2 = -sum(problem * log2(a_data))
print h_x1_x2
#NaN
----------------------------------------------------------
I need a way of handling NaNs for example R has the ''na.omit'' option. Does anybody know if this exists?
Many thanks
Andy
On 2006-05-03, Andy McDonagh <an**********@earthlink.net> wrote:Dear python experts,
I am new to python and this site, so I apologize if this is off topic (i.e. is it a SciPy question?). I will try to demonstrate my problem below:
--------------------------------------------------------
#!/usr/local/bin/python
from scipy import *
from scipy.stats import *
a=norm(loc=0,scale=1)
a_data = a.rvs(10)
problem = zeros(10)
print problem
h_x1_x2 = -sum(problem * log2(a_data))
print h_x1_x2
#NaN
----------------------------------------------------------
I need a way of handling NaNs
NaNs are handled.
Apparently they aren''t handled the way you want them to be?
for example R has the ''na.omit'' option. Does anybody know if
this exists?
It would help if you explain how you want NaNs handled, but I
don''t recall that tehre are any "options" for handling NaNs
other than the default way in scipy.
--
Grant Edwards grante Yow! It''s NO USE... I''ve
at gone to "CLUB MED"!!
visi.com
<snip>
NaNs are handled.
Throwing an exception would be nice in regular Python (non-scipy).
This works to catch NaN on OSX and Linux:
# assuming x is a number
if x+1==x or x!=x:
#x is NaN
But is expensive as a precautionary measure.
Assert can be used for testing, if production code can be run with -0
or -OO.
On 2006-05-05, Ivan Vinogradov <vi*****@mcmaster.ca> wrote:<snip>
NaNs are handled.
Throwing an exception would be nice in regular Python (non-scipy).
That would break most of my Python programs (at least most of
the ones in which I do floating point). My main problem with
NaNs (and Infs) is that there isn''t a string represention that
is consistent across platforms.
This works to catch NaN on OSX and Linux:
# assuming x is a number
if x+1==x or x!=x:
#x is NaN
But is expensive as a precautionary measure. Assert can be
used for testing, if production code can be run with -0 or
-OO.
There are those of us that need NaNs in production code, so it
would have to be something that could be configured. I find
that in my programs the places where I need to do something
"exceptional" with a NaN are very limited. The vast majority
of the time, I need them to propagate quietly.
--
Grant Edwards grante Yow! Thousands of days of
at civilians... have produced
visi.com a... feeling for the
aesthetic modules --
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