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※ 引述《xavierqqqq (Eye煙霧瀰漫)》之銘言: : 假如 X 是 data matrix : - T -1 - : 要得出 dj = (xj-x) s (xj-x) j=1....n : 我只會一個一個算 : 請問有什麼辦法可以很快就把n個算出來? : 因為n很大時不知道該怎辦 3Q Hi 將以下的latex code貼至 http://www.sciencesoft.at/index.jsp?link=latex&lang=en 大框內. Format改成pdfwrite會出現papersize,再選a4 完成以上設定後按Start latex開始執行程式 程式執行後下方有個link,點下去可以看見pdf檔 %%%%%%%%%%%%%% The below: latex code %%%%%%%%%%%%%%%%%%% \documentclass[11pt]{letter} \usepackage{amsmath} \begin{document} Hello, you can try it as follows. Given the $ N \times P $ data matrix $ {\bf X} $ and $ {\bf 1}^T=[\underbrace{1,1,\dots,1}_{N}] $. Let $ \overline{{\bf x}} = \left( \frac{1}{N} \right) {\bf X}^T{\bf 1} $, and then you can calculate deviation matrix $ {\bf D_X}={\bf X}- {\bf 1}\overline{{\bf x}}^T$. The diagonal part of $ \left( {\bf D_X} \right) {\bf S}^{-1} \left( {\bf D_X} \right)^T$ is what you want. \end{document} %%%%%%%%%%%%%% The above: latex code %%%%%%%%%%%%%%%%%%% -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.113.114.165
xavierqqqq:非常感謝 04/02 22:43