std does not give good values?

14 次查看（过去 30 天）
f10w
f10w 2013-11-14
评论： f10w 2013-11-28
Hello everybody,
For this matrix
M = [1 2; 3 4];
if we compute the its standard deviation
std(M(:))
then we obtain 1.2910, while by definition, it should be 1.1180. Why is there such a difference?
Thank you for your help.

请先登录，再回答此问题。

采纳的回答

Roger Stafford
Roger Stafford 2013-11-14
编辑：Roger Stafford 2013-11-14
The 1.2910 value is the unbiased standard deviation which is default while the 1.1118 value is the second moment. Read the documentation for 'std' at:
http://www.mathworks.com/help/matlab/ref/std.html

更多回答（0 个）

类别

在 Help Center 和 File Exchange 中查找有关 Probability Distributions and Hypothesis Tests 的更多信息

标签

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by