on 发帖数: 199 | 1 有没有人能讲一下DF 的直观? 或者 some links? Thanks | s*****9 发帖数: 108 | 2 我举得“自由度”这个翻译就是个直观的解释,衡量一个system/data/space里面可以
自由变化的参数/变量的个数呗。 | d**********r 发帖数: 24123 | 3 大衍之数五十,其用四十有九
就是这个意思。
转贴鲁妙子的解释:假设一间房子只能摆五十张凳子。如果放入满满五十张,那就谁也
动不了。但是只要去掉一,那剩下的四十九张凳子就都可以自由的动了。
后来有人把这个概念偷去了,改名 Degree of freedom | a***r 发帖数: 420 | 4 我跟你有相同的困惑
最近发现一篇很好的文章,正在读,与你分享
http://courses.ncssm.edu/math/Stat_Inst/PDFS/DFWalker.pdf
【在 on 的大作中提到】 : 有没有人能讲一下DF 的直观? 或者 some links? Thanks
| on 发帖数: 199 | 5 Thanks.
I understand the meaning of dimensionality, etc, and why we call it degree
of freedom.
What puzzled or amazed me is this: in many estimators, when we adjust for
degree of freedom, then we get an unbiased estimator. A simple example is
the unbiased estimator for std has divisor N-1 instead of N where N-1 is the
degree of freedom. I can go through the algebra, but the question is: what
intuition explain that the role of degree of freedom? Or is it just another
example of the grace of math?
【在 a***r 的大作中提到】 : 我跟你有相同的困惑 : 最近发现一篇很好的文章,正在读,与你分享 : http://courses.ncssm.edu/math/Stat_Inst/PDFS/DFWalker.pdf
| a***r 发帖数: 420 | 6 hand,exactly my questions...
yeah that paper does not explain this issue
maybe as you said, there is no good way to elaborate it intuitively,
or we need dig up the mathematics under statistics methods in more
depth...
degree
for
is
is the
what
another
【在 on 的大作中提到】 : Thanks. : I understand the meaning of dimensionality, etc, and why we call it degree : of freedom. : What puzzled or amazed me is this: in many estimators, when we adjust for : degree of freedom, then we get an unbiased estimator. A simple example is : the unbiased estimator for std has divisor N-1 instead of N where N-1 is the : degree of freedom. I can go through the algebra, but the question is: what : intuition explain that the role of degree of freedom? Or is it just another : example of the grace of math?
| L**********A 发帖数: 7115 | 7 还蛮intuitive 的,而且不是什么 magic,grace的 ..
比如 5个数字加一起等于 100,你确定了4个数字,第五个就只能有一个结果,所以df
是4 不是5
【在 a***r 的大作中提到】 : hand,exactly my questions... : yeah that paper does not explain this issue : maybe as you said, there is no good way to elaborate it intuitively, : or we need dig up the mathematics under statistics methods in more : depth... : : degree : for : is : is the
| a*****3 发帖数: 601 | 8 为什么不是"5个数字加(加,减,乘,除,etc)一起等于 100,你确定了4个数字,第五
个就只能有一个结果,所以df 是4 不是5" , 嘿嘿。
df 是4 不是5
【在 L**********A 的大作中提到】 : 还蛮intuitive 的,而且不是什么 magic,grace的 .. : 比如 5个数字加一起等于 100,你确定了4个数字,第五个就只能有一个结果,所以df : 是4 不是5
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