关于matlab的问题哪位高手能帮帮我啊！急！急！

显示全部楼层 · 2011-4-19 03:40:16

t=[0.25,0.5,0.75,1,1.5,2,2.5,3,3.5,4,4.5,5,6,7,8,9,10,11,12,13,14,15,16];
C=[30,68,75,82,82,77,68,68,58,51,50,41,38,35,28,25,18,15,12,10,7,7,4];
f=inline(\'k(3)*(k（1）/(k(1)-k(2))*(exp(-k(2)*t)-exp(-k(1)*t))\',\'k\',\'t\');
[k,res]=lsqcurvefit(f,[1,0,82],t,C);
??? Error using == optim\\private\\lsqncommon
User supplied expression or inline function == k(3)*(k（1）/(k(1)-k(2))*(exp(-k(2)*t)-exp(-k(1)*t))
failed with the following error:

Error using == inlineeval
Error in inline expression == k(3)*(k（1）/(k(1)-k(2))*(exp(-k(2)*t)-exp(-k(1)*t))
??? Error: Missing variable or function.

Error in == lsqcurvefit at 149
[x,Resnorm,FVAL,EXITFLAG,OUTPUT,LAMBDA,JACOB] = ...
为什么会出现这样的问题啊？应该怎么修改！

千问 · 2011-4-19 03:40:16

<pre id=\"best-answer-content\" class=\"reply-text mb10\">你的inline函数有问题：少了个括号的！我不知道你到底在那里断开，自己检查吧
补充一下：
x = [0,1,2,3,4,5]\';
y = [0,1,4,9,16,25]\';
f = inline(\'C(1) C(2)*t C(3)*t.^2C(4)*t.^3\',\'C\',\'t\');
ff = optimset;
ff.TolFun=1e-20;
ff.TolX=1e-15;
x0 = [0,0,0,0];
% 初始值
[C,res] = lsqcurvefit(f,x0,x,y,[],[],ff)
y1=f(C,x);
plot(x,y,\'-b\',x,y1,\'-or\')