Python鍜孯鍙奙ATLAB鍜孋涓嶭ua鍘荤浉鍏崇敓鐗╁尰瀛﹀浘鍍忓鐞嗗拰绁炵粡缃戠粶鐗╃悊瀛﹀強鏁板鍙樻崲绠楁硶

馃幆瑕佺偣

  1. 涓绘垚鍒嗗垎鏋愰檷缁?/li>
  2. 鏄惧井闀滄垚鍍忕簿搴﹁瘎浼扮畻娉?/li>
  3. 鑴戠數鍥剧鍏辨尟鎴愬儚闄嶅櫔绠楁硶
  4. 鍥惧儚棰滆壊鍒嗙鏄剧幇鐗瑰緛
  5. 鐞冮潰杞崲:涓绘垚鍒嗗垎鏋愬拰闆剁浉浣嶅垎閲忓垎鏋?/li>
  6. 闆剁浉浣嶅垎閲忓垎鏋愬拰涓绘垚鍒嗗垎鏋愬钩鍧囦簰鐩稿叧绠楁硶
  7. 鍥惧儚鐧藉寲
  8. 璁$畻鍣0鍗忔柟宸拰缁樺埗鐧藉寲鏁版嵁
  9. 楂樿兘鐗╃悊鍒嗙被鍣ㄥ垎绂讳笉鍚屼俊鍙?/li>
  10. 鐧藉寲鍙樻崲浼樺寲鎵归噺褰掍竴鍖?/li>
  11. 鍘荤浉鍏冲姣旂壒寰佸涔?/li>
  12. 鐢熺墿鍥惧儚鍘荤浉鍏冲垎鏋愬紩鎿?鍦ㄨ繖閲屾彃鍏ュ浘鐗囨弿杩? /></li></ol> 
<h3>Python鐧藉寲</h3> 
<p>鐧藉寲鍙樻崲鎴栫悆闈㈠彉鎹㈡槸涓€绉嶇嚎鎬у彉鎹紝瀹冨皢鍏锋湁宸茬煡鍗忔柟宸煩闃电殑闅忔満鍙橀噺鍚戦噺杞崲涓轰竴缁勫崗鏂瑰樊涓哄崟浣嶇煩闃电殑鏂板彉閲忥紝杩欐剰鍛崇潃瀹冧滑涓嶇浉鍏充笖姣忎釜鍙橀噺鐨勬柟宸负 1銆傝繖绉嶅彉鎹㈣绉颁负鈥滅櫧鍖栤€濓紝鍥犱负瀹冨皢杈撳叆鍚戦噺鏇存敼涓虹櫧鍣0鍚戦噺銆?/p> 
<p>鍏朵粬鍑犱釜杞彉涓庣櫧鍖栧瘑鍒囩浉鍏筹細</p> 
<ul><li>鍘荤浉鍏冲彉鎹粎鍒犻櫎鐩稿叧鎬э紝浣嗕繚鎸佹柟宸笉鍙樸€?/li><li>鏍囧噯鍖栧彉鎹㈠皢鏂瑰樊璁剧疆涓?1锛屼絾淇濇寔鐩稿叧鎬т笉鍙樸€?/li><li>鐫€鑹插彉鎹㈠皢鐧借壊闅忔満鍙橀噺鍚戦噺鍙樻崲涓哄叿鏈夋寚瀹氬崗鏂瑰樊鐭╅樀鐨勯殢鏈哄悜閲忋€?/li></ul> 
<p>鍋囪 <span ><span ><span > 
     
      
       
       
         X 
        
       
      
        X 
       
      
    </span><span ><span ><span  ></span><span  >X</span></span></span></span></span> 鏄竴涓殢鏈猴紙鍒楋級鍚戦噺锛屽叿鏈夐潪濂囧紓鍗忔柟宸煩闃?<span ><span ><span > 
     
      
       
       
         危 
        
       
      
        \Sigma 
       
      
    </span><span ><span ><span  ></span><span >危</span></span></span></span></span> 鍜屽钩鍧囧€?0 銆傜劧鍚庯紝浣跨敤婊¤冻鏉′欢 <span ><span ><span > 
     
      
       
        
        
          W 
         
        
          T 
         
        
       
         W 
        
       
         = 
        
        
        
          危 
         
         
         
           鈭?
          
         
           1 
          
         
        
       
      
        W^{ T } W=\Sigma^{-1} 
       
      
    </span><span ><span ><span  ></span><span ><span  >W</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span  >T</span></span></span></span></span></span></span></span></span><span  >W</span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span >危</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >鈭?/span><span >1</span></span></span></span></span></span></span></span></span></span></span></span></span> 鐨勭櫧鍖栫煩闃?<span ><span ><span > 
     
      
       
       
         W 
        
       
      
        W 
       
      
    </span><span ><span ><span  ></span><span  >W</span></span></span></span></span> 杩涜鍙樻崲 <span ><span ><span > 
     
      
       
       
         Y 
        
       
         = 
        
       
         W 
        
       
         X 
        
       
      
        Y=W X 
       
      
    </span><span ><span ><span  ></span><span  >Y</span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span  >W</span><span  >X</span></span></span></span></span>锛岀敓鎴愬叿鏈夊崟浣嶅瑙掑崗鏂瑰樊鐨勭櫧鍖栭殢鏈哄悜閲?<span ><span ><span > 
     
      
       
       
         Y 
        
       
      
        Y 
       
      
    </span><span ><span ><span  ></span><span  >Y</span></span></span></span></span>銆?/p> 
<p>鏈夋棤闄愬涓彲鑳界殑鐧藉寲鐭╅樀<span ><span ><span > 
     
      
       
       
         W 
        
       
      
        W 
       
      
    </span><span ><span ><span  ></span><span  >W</span></span></span></span></span>閮芥弧瓒充笂杩版潯浠躲€傚父鐢ㄧ殑閫夋嫨鏄?span ><span ><span > 
     
      
       
       
         W 
        
       
         = 
        
        
        
          危 
         
         
         
           鈭?
          
         
           1 
          
         
           / 
          
         
           2 
          
         
        
       
      
        W=\Sigma^{-1 / 2} 
       
      
    </span><span ><span ><span  ></span><span  >W</span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span >危</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >鈭?/span><span >1/2</span></span></span></span></span></span></span></span></span></span></span></span></span>锛堥浂鐩镐綅鍒嗛噺鍒嗘瀽鐧藉寲锛夛紝<span ><span ><span > 
     
      
       
       
         W 
        
       
         = 
        
        
        
          L 
         
        
          T 
         
        
       
      
        W=L^T 
       
      
    </span><span ><span ><span  ></span><span  >W</span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span >L</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span  >T</span></span></span></span></span></span></span></span></span></span></span></span>锛屽叾涓?span ><span ><span > 
     
      
       
       
         L 
        
       
      
        L 
       
      
    </span><span ><span ><span  ></span><span >L</span></span></span></span></span>鏄?span ><span ><span > 
     
      
       
        
        
          危 
         
         
         
           鈭?
          
         
           1 
          
         
        
       
      
        \Sigma^{-1} 
       
      
    </span><span ><span ><span  ></span><span ><span >危</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >鈭?/span><span >1</span></span></span></span></span></span></span></span></span></span></span></span></span>鐨凜holesky鍒嗚В锛?Cholesky 鐧藉寲锛夛紝鎴?<span ><span ><span > 
     
      
       
       
         危 
        
       
      
        \Sigma 
       
      
    </span><span ><span ><span  ></span><span >危</span></span></span></span></span> 鐨勭壒寰佺郴缁燂紙涓绘垚鍒嗗垎鏋愮櫧鍖栵級銆?/p> 
<p>鍙互閫氳繃鐮旂┒ <span ><span ><span > 
     
      
       
       
         X 
        
       
      
        X 
       
      
    </span><span ><span ><span  ></span><span  >X</span></span></span></span></span> 鍜?<span ><span ><span > 
     
      
       
       
         Y 
        
       
      
        Y 
       
      
    </span><span ><span ><span  ></span><span  >Y</span></span></span></span></span> 鐨勪簰鍗忔柟宸拰浜掔浉鍏虫潵閫夊嚭鏈€浣崇櫧鍖栧彉鎹€?渚嬪锛屽湪鍘熷 <span ><span ><span > 
     
      
       
       
         X 
        
       
      
        X 
       
      
    </span><span ><span ><span  ></span><span  >X</span></span></span></span></span> 鍜岀櫧鍖栧悗鐨?<span ><span ><span > 
     
      
       
       
         Y 
        
       
      
        Y 
       
      
    </span><span ><span ><span  ></span><span  >Y</span></span></span></span></span> 涔嬮棿瀹炵幇鏈€澶у垎閲忕浉鍏虫€х殑鍞竴鏈€浼樼櫧鍖栧彉鎹㈡槸鐢辩櫧鍖栫煩闃?<span ><span ><span > 
     
      
       
       
         W 
        
       
         = 
        
        
        
          P 
         
         
         
           鈭?
          
         
           1 
          
         
           / 
          
         
           2 
          
         
        
        
        
          V 
         
         
         
           鈭?
          
         
           1 
          
         
           / 
          
         
           2 
          
         
        
       
      
        W=P^{-1 / 2} V^{-1 / 2} 
       
      
    </span><span ><span ><span  ></span><span  >W</span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span  >P</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >鈭?/span><span >1/2</span></span></span></span></span></span></span></span></span><span ><span  >V</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >鈭?/span><span >1/2</span></span></span></span></span></span></span></span></span></span></span></span></span>锛屽叾涓?<span ><span ><span > 
     
      
       
       
         P 
        
       
      
        P 
       
      
    </span><span ><span ><span  ></span><span  >P</span></span></span></span></span> 鏄浉鍏崇煩闃碉紝<span ><span ><span > 
     
      
       
       
         V 
        
       
      
        V 
       
      
    </span><span ><span ><span  ></span><span  >V</span></span></span></span></span> 鏄柟宸煩闃点€?/p> 
<h4>鍗忔柟宸煩闃?/h4> 
<p><span ><span ><span ><span > 
      
       
        
         
         
           x 
          
         
           variance聽 
          
         
        
          = 
         
         
          
           
           
             鈭?
            
            
            
              i 
             
            
              = 
             
            
              1 
             
            
           
             n 
            
           
           
            
            
              ( 
             
             
             
               x 
              
             
               i 
              
             
            
              鈭?
             
             
             
               x 
              
             
               mean聽 
              
             
            
              ) 
             
            
           
             2 
            
           
          
         
           n 
          
         
        
       
         x_{\text {variance }}=\frac{\sum_{i=1}^n\left(x_i-x_{\text {mean }}\right)^2}{n} 
        
       
     </span><span ><span ><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >variance聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span ></span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >n</span></span></span><span  ><span  ></span><span  ></span></span><span  ><span  ></span><span ><span ><span  >鈭?/span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >i</span><span >=</span><span >1</span></span></span></span><span  ><span  ></span><span ><span >n</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span ><span ><span  >(</span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >i</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >鈭?/span><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >mean聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  >)</span></span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >2</span></span></span></span></span></span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span><span ></span></span></span></span></span></span></span></p> 
<p><span ><span ><span ><span > 
      
       
        
         
         
           x 
          
         
           covariance聽 
          
         
        
          = 
         
         
          
           
           
             鈭?
            
            
            
              i 
             
            
              = 
             
            
              1 
             
            
           
             n 
            
           
           
           
             ( 
            
            
            
              x 
             
            
              i 
             
            
           
             鈭?
            
            
            
              x 
             
            
              mean聽 
             
            
           
             ) 
            
           
           
           
             ( 
            
            
            
              y 
             
            
              i 
             
            
           
             鈭?
            
            
            
              y 
             
            
              mean聽 
             
            
           
             ) 
            
           
          
         
           n 
          
         
        
       
         x_{\text {covariance }}=\frac{\sum_{i=1}^n\left(x_i-x_{\text {mean }}\right)\left(y_i-y_{\text {mean }}\right)}{n} 
        
       
     </span><span ><span ><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >covariance聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span ></span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >n</span></span></span><span  ><span  ></span><span  ></span></span><span  ><span  ></span><span ><span ><span  >鈭?/span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >i</span><span >=</span><span >1</span></span></span></span><span  ><span  ></span><span ><span >n</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span ><span  >(</span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >i</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >鈭?/span><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >mean聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  >)</span></span><span  ></span><span ><span  >(</span><span ><span  >y</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >i</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >鈭?/span><span  ></span><span ><span  >y</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >mean聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  >)</span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span><span ></span></span></span></span></span></span></span></p> 
<p><span ><span ><span ><span > 
      
       
        
         
         
           x 
          
         
           variance聽 
          
         
        
          = 
         
         
          
           
           
             鈭?
            
            
            
              i 
             
            
              = 
             
            
              1 
             
            
           
             n 
            
           
           
            
            
              ( 
             
             
             
               x 
              
             
               i 
              
             
            
              鈭?
             
             
             
               x 
              
             
               mean聽 
              
             
            
              ) 
             
            
           
             2 
            
           
          
          
          
            n 
           
          
            鈭?
           
          
            1 
           
          
         
        
       
         x_{\text {variance }}=\frac{\sum_{i=1}^n\left(x_i-x_{\text {mean }}\right)^2}{n-1} 
        
       
     </span><span ><span ><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >variance聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span ></span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >n</span><span  ></span><span >鈭?/span><span  ></span><span >1</span></span></span><span  ><span  ></span><span  ></span></span><span  ><span  ></span><span ><span ><span  >鈭?/span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >i</span><span >=</span><span >1</span></span></span></span><span  ><span  ></span><span ><span >n</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span ><span ><span  >(</span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >i</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >鈭?/span><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >mean聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  >)</span></span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >2</span></span></span></span></span></span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span><span ></span></span></span></span></span></span></span></p> 
<p><span ><span ><span ><span > 
      
       
        
         
         
           x 
          
         
           covariance聽 
          
         
        
          = 
         
         
          
           
           
             鈭?
            
            
            
              i 
             
            
              = 
             
            
              1 
             
            
           
             n 
            
           
           
           
             ( 
            
            
            
              x 
             
            
              i 
             
            
           
             鈭?
            
            
            
              x 
             
            
              mean聽 
             
            
           
             ) 
            
           
           
           
             ( 
            
            
            
              y 
             
            
              i 
             
            
           
             鈭?
            
            
            
              y 
             
            
              mean聽 
             
            
           
             ) 
            
           
          
          
          
            n 
           
          
            鈭?
           
          
            1 
           
          
         
        
       
         x_{\text {covariance }}=\frac{\sum_{i=1}^n\left(x_i-x_{\text {mean }}\right)\left(y_i-y_{\text {mean }}\right)}{n-1} 
        
       
     </span><span ><span ><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >covariance聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span ></span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >n</span><span  ></span><span >鈭?/span><span  ></span><span >1</span></span></span><span  ><span  ></span><span  ></span></span><span  ><span  ></span><span ><span ><span  >鈭?/span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >i</span><span >=</span><span >1</span></span></span></span><span  ><span  ></span><span ><span >n</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span ><span  >(</span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >i</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >鈭?/span><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >mean聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  >)</span></span><span  ></span><span ><span  >(</span><span ><span  >y</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >i</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >鈭?/span><span  ></span><span ><span  >y</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >mean聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  >)</span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span><span ></span></span></span></span></span></span></span></p> 
<p>鍏朵腑锛?/p> 
<ul><li><span ><span ><span > 
      
       
        
         
         
           x 
          
         
           variance聽 
          
         
        
          : 
         
        
       
         x _{\text {variance }}: 
        
       
     </span><span ><span ><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >variance聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >:</span></span></span></span></span> 鏄壒寰佺殑鏂瑰樊</li><li><span ><span ><span > 
      
       
        
         
         
           x 
          
         
           covariance聽 
          
         
        
       
         x_{\text {covariance }} 
        
       
     </span><span ><span ><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span >covariance聽</span></span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span></span></span></span></span> 锛氭槸鐗瑰緛 <span ><span ><span > 
      
       
        
        
          x 
         
        
       
         x 
        
       
     </span><span ><span ><span  ></span><span >x</span></span></span></span></span> 鍜?<span ><span ><span > 
      
       
        
        
          y 
         
        
       
         y 
        
       
     </span><span ><span ><span  ></span><span  >y</span></span></span></span></span> 涔嬮棿鐨勫崗鏂瑰樊</li><li><span ><span ><span > 
      
       
        
         
         
           x 
          
         
           i 
          
         
        
       
         x_i 
        
       
     </span><span ><span ><span  ></span><span ><span >x</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >i</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span></span></span></span></span> 鍜?<span ><span ><span > 
      
       
        
         
         
           y 
          
         
           i 
          
         
        
       
         y_i 
        
       
     </span><span ><span ><span  ></span><span ><span  >y</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span >i</span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span></span></span></span></span> 锛氭槸鐗瑰緛 <span ><span ><span > 
      
       
        
        
          x 
         
        
       
         x 
        
       
     </span><span ><span ><span  ></span><span >x</span></span></span></span></span> 鍜?<span ><span ><span > 
      
       
        
        
          y 
         
        
       
         y 
        
       
     </span><span ><span ><span  ></span><span  >y</span></span></span></span></span> 鐨勫崟鐙暟鎹偣</li><li><span ><span ><span > 
      
       
        
        
          危 
         
        
       
         \Sigma 
        
       
     </span><span ><span ><span  ></span><span >危</span></span></span></span></span> 锛氳〃绀哄€肩殑鎬诲拰</li><li>n 锛氭槸鏌愪釜鐗瑰緛鐨勮瀵熸鏁?/li></ul> 
<h4>鐗瑰緛鍊煎拰鐗瑰緛鍚戦噺</h4> 
<p><span ><span ><span ><span > 
      
       
        
        
          A 
         
        
          鈭?
         
        
          位 
         
        
          I 
         
        
          = 
         
        
          0 
         
        
       
         A-\lambda I=0 
        
       
     </span><span ><span ><span  ></span><span >A</span><span  ></span><span >鈭?/span><span  ></span></span><span ><span  ></span><span >位</span><span  >I</span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span >0</span></span></span></span></span></span></p> 
<p><span ><span ><span ><span > 
      
       
        
        
          A 
         
        
          v 
         
        
          = 
         
        
          位 
         
        
          v 
         
        
       
         A v=\lambda v 
        
       
     </span><span ><span ><span  ></span><span >A</span><span  >v</span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span >位</span><span  >v</span></span></span></span></span></span></p> 
<ul><li>A锛氱壒寰佺殑鍗忔柟宸煩闃?/li><li><span ><span ><span > 
      
       
        
        
          位 
         
        
       
         \lambda 
        
       
     </span><span ><span ><span  ></span><span >位</span></span></span></span></span> 锛氭槸鐗瑰緛鍊肩煩闃?/li><li>I锛氭槸鍗曚綅鐭╅樀</li><li>v锛氭槸鐗瑰緛鍚戦噺鐨勭煩闃?/li></ul> 
<h4>涓绘垚鍒嗗垎鏋愮櫧鍖栨柟绋?/h4> 
<p><span ><span ><span ><span > 
      
       
        
         
         
           W 
          
          
          
            P 
           
          
            C 
           
          
            A 
           
          
         
        
          = 
         
         
         
           螞 
          
          
           
           
             鈭?
            
           
             1 
            
           
          
            2 
           
          
         
         
         
           U 
          
         
           T 
          
         
        
          X 
         
        
       
         W_{P C A}=\Lambda^{\frac{-1}{2}} U^T X 
        
       
     </span><span ><span ><span  ></span><span ><span  >W</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span  >PC</span><span >A</span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span ><span >螞</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span ></span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >2</span></span></span></span><span  ><span  ></span><span  ></span></span><span  ><span  ></span><span ><span ><span >鈭?/span><span >1</span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span><span ></span></span></span></span></span></span></span></span></span></span><span ><span  >U</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span  >T</span></span></span></span></span></span></span></span><span  >X</span></span></span></span></span></span></p> 
<h4>闆剁浉浣嶅垎閲忓垎鏋愮櫧鍖栨柟绋?/h4> 
<p><span ><span ><span ><span > 
      
       
        
         
         
           W 
          
          
          
            Z 
           
          
            C 
           
          
            A 
           
          
         
        
          = 
         
        
          U 
         
         
         
           螞 
          
          
           
           
             鈭?
            
           
             1 
            
           
          
            2 
           
          
         
         
         
           U 
          
         
           T 
          
         
        
          X 
         
        
       
         W_{Z C A}=U \Lambda^{\frac{-1}{2}} U^T X 
        
       
     </span><span ><span ><span  ></span><span ><span  >W</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span  >ZC</span><span >A</span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span></span><span  ></span><span >=</span><span  ></span></span><span ><span  ></span><span  >U</span><span ><span >螞</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span ><span ></span><span ><span ><span ><span  ><span  ><span  ></span><span ><span ><span >2</span></span></span></span><span  ><span  ></span><span  ></span></span><span  ><span  ></span><span ><span ><span >鈭?/span><span >1</span></span></span></span></span><span >鈥?/span></span><span ><span  ><span ></span></span></span></span></span><span ></span></span></span></span></span></span></span></span></span></span><span ><span  >U</span><span ><span ><span ><span  ><span  ><span  ></span><span ><span  >T</span></span></span></span></span></span></span></span><span  >X</span></span></span></span></span></span></p> 
<h4>Python鐧藉寲</h4> 
<pre><code >import numpy as np
import matplotlib.pyplot as plt
from scipy import linalg
 
x = np.array([[1,2,3,4,5],  
              [11,12,13,14,15]]) 
print('x.shape:', x.shape)

xc = x.T - np.mean(x.T, axis=0)
xc = xc.T
print('xc.shape:', xc.shape, '\n')

xcov = np.cov(xc, rowvar=True, bias=True)
print('Covariance matrix: \n', xcov, '\n')

w, v = linalg.eig(xcov)

print(
    x.shape: (2, 5)
    xc.shape: (2, 5) 
     
    Covariance matrix: 
     [[2. 2.]
     [2. 2.]] 
     
    Eigenvalues:
     [4. 0.] 
     
    Eigenvectors:
     [[ 0.70710678 -0.70710678]
     [ 0.70710678  0.70710678]] 
     
    Diagonal matrix for inverse square root of Eigenvalues:
     [[5.00000000e-01 0.00000000e+00]
     [0.00000000e+00 4.74531328e+07]] 
    

    馃憠鏇存柊锛氫簹鍥捐法闄?/h3>

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