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标题: 求拟合代码 [打印本页]

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作者: woshiluyu666    时间: 2013-5-18 13:34
标题: 求拟合代码
t=[1,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,31,32,35,37,39,47];
x=[3,7,8,12,15,16,19,22,26,31,36,41,47,58,61,75,80,85,89,90,94,102,102,108,112,114,116,121,124,126,128,128,130,131];
plot(t,x,'*')
  \/ u: X8 b$ ]4 l6 w% C b0=[0.46,5.3,-0.45];
fun=inline('b(1)/(1+b(2)*exp(b(3)*t))','b','t');
- m7 h; _& P2 J2 A1 V/ E [b,r,j]=nlinfit(t,x,fun,b0);
5 }9 W9 q" H; I" Tb
。。
请问大神们，为什么老是出现错误呢，麻烦帮我检查fun=inline('b(1)/(1+b(2)*exp(b(3)*t))','b','t');
这句哪儿出错了，急求。。

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作者: madio    时间: 2013-8-20 17:49

1. t=[1,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,31,32,35,37,39,47];
   
2. x=[3,7,8,12,15,16,19,22,26,31,36,41,47,58,61,75,80,85,89,90,94,102,102,108,112,114,116,121,124,126,128,128,130,131];
   + S0 x# J# _0 p4 X& g) N9 s
3. plot(t,x,'*');
   ! _" x, x5 Q) G: I6 u: P/ L0 u# F
4. b0=[0.46,5.3,-0.45];
   + v7 K* h2 y; p& ]9 i
5. fun=inline('b(1)./(1+b(2)*exp(b(3)*t))','b','t');
   
6. [b,r,j]=nlinfit(t,x,fun,b0);
   
7. b

复制代码

改了一下，你试试看

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作者: 净心、精心    时间: 2013-8-20 20:17
fun=inline('b(1)./(1+b(2)*exp(b(3)*t))','b','t');换成点除

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