æ¹æ³/æ¥éª¤
1
æ°æ®åå¤ï¼
æ们以ä¸ç»å¤é¡¹å¼æ°æ®ä¸ºä¾ï¼è¿è¡ç¤ºä¾ï¼åå¦å¤é¡¹å¼æ¯y=4x^3+3x^2+2产ççæ°æ®ï¼xå0å°3ä¹é´é´é为0.3çæ°ãå
·ä½æ°æ®å¦ä¸ï¼
2
è°ç¨å·¥å
·ç®±ï¼
å
³äºå¦ä½è°ç¨å·¥å
·ç®±æå¨å
¶ä»ç»éªä¸æ详ç»çä»ç»ï¼æå
´è¶£çå¯ä»¥æ¥çã
è¿éæ们ç¨å½ä»¤cftoolè¿è¡è°ç¨æåå·¥å
·ç®±ï¼å¨MATLAB主çªå£ä¸è¾å
¥ cftool å车
å¯ä»¥çå°å¦ä¸æåå·¥å
·ç®±çé¢
3
æåæä½æ¥éª¤ï¼
é¦å
æ们å°è¦æåçæ°æ®éå
¥å°å·¥å
·ç®±ä¸ï¼å¦ä¸å¾ï¼å¨çº¢åå¤ï¼ç¹å»åä¸ä¸è§ï¼åå«å°è¦æåçx y éå
¥ï¼ç¶åç¹å»å³ä¾§çæä¸æ¹çä¸ä¸è§ï¼ç¶åéæ©polynomialï¼ å¤é¡¹å¼ï¼ï¼ä¸é¢çdegreeæ¯é¶æ°ï¼ä¹å°±æ¯xçæé«æ¬¡æ°ï¼éæ©ä¸åçdegreeï¼å¨å¾çå·¦ä¸è§æ¯æåçç»æï¼å
æ¬æåçç³»æ°ä»¥åæ¹å·®ç¸å
³ç³»æ°çï¼å³ä¾§æ¯æ°æ®ç¹ï¼ä»¥æåæ²çº¿ã
4
ç»æåæï¼
æ们æåçæ¶åï¼ä¸è¬æ
åµä¸ä¸ç¥éè¦æåçå¤é¡¹å¼æ¯å é¶çï¼æ们ä¸è¬è°èdegreeé½æ¯ä»1éæ¸å¢å¤§ï¼åªè¦ç²¾åº¦ç¬¦åè¦æ±ï¼å°±å¯ä»¥äºï¼å¹¶ä¸æ¯ç²¾åº¦è¶é«è¶é«ã
æåç»æ说æï¼
Linear model Poly3:
f(x) = p1*x^3 + p2*x^2 + p3*x + p4
Coefficients (with 95% confidence bounds):
p1 = 4 (4, 4)
p2 = 3 (3, 3)
p3 = 4.593e-15 (-3.266e-14, 4.185e-14)
p4 = 2 (2, 2)
Goodness of fit:
SSE: 2.386e-28
R-square: 1
Adjusted R-square: 1
RMSE: 5.839e-15
ä»ä»¥ä¸å¯ä»¥çå°æç»æåçyå
³äºxçå½æ°ä¸ºï¼
f(x)=4*x^3+3*x^2+4.593e-15*x+2
æ们å¯ä»¥çå°ä¸æ¬¡é¡¹çç³»æ°ä¸º4.593e-15ï¼å®é
ä¸å°±æ¯4.593*10^ï¼-15ï¼ï¼è¿ä¸ªæ°é级å®å
¨å¯ä»¥è®¤ä¸ºæ¯0ï¼æ以æåçç»ææ们认为æ¯ï¼
f(x)=4*x^3+3*x^2+2
è¿éçæ¹å·®SSEæ°é级为10çè´28次æ¹ï¼ç¸å
³ç³»æ° R-square=1ï¼è¯´ææåçç»æå¾å¥½ã
温馨提示:答案为网友推荐,仅供参考