yujiebq
2009-02-12, 15:15
我想求解的方程包含一个代数式Dm,它的形式定义在程序中了。
v是自变量,方程的样子是:
2*Dm*(y对v的二阶倒数)+2*(Dm对v的一阶导数)*(y对v的一阶导数)+y*(y对v的一阶导数)^2=0
(其实方程中不是y,是λ,可是我不知道如何在命令窗口输入!!!)
syms v;
>> Dm=0.77*10^(-10)*exp(-0.061*v);
>> diffDm=diff(Dm)
diffDm =
-363412772782714473/77371252455336267181195264000*exp(-61/1000*v)
>> dsolve('y*(Dy)^2+2*diffDm*Dy+2*Dm*D2y=0','y(0.0033)=0')
??? Subscript indices must either be real positive integers or logicals.
Error in ==> dsolve at 200
indx(isalphanumunder(eq_str(indx-1))|isalphanumunder(eq_str(indx-1))) = [];
不知道为什么错误,MATLAB看不懂我写什么吧,不懂我要做什么!感慨啊!我都鼓捣好几天了,还是不会写!
请前辈高手们指点一下吧!万分感激!急盼回复啊!~~~~(>_<)~~~~
v是自变量,方程的样子是:
2*Dm*(y对v的二阶倒数)+2*(Dm对v的一阶导数)*(y对v的一阶导数)+y*(y对v的一阶导数)^2=0
(其实方程中不是y,是λ,可是我不知道如何在命令窗口输入!!!)
syms v;
>> Dm=0.77*10^(-10)*exp(-0.061*v);
>> diffDm=diff(Dm)
diffDm =
-363412772782714473/77371252455336267181195264000*exp(-61/1000*v)
>> dsolve('y*(Dy)^2+2*diffDm*Dy+2*Dm*D2y=0','y(0.0033)=0')
??? Subscript indices must either be real positive integers or logicals.
Error in ==> dsolve at 200
indx(isalphanumunder(eq_str(indx-1))|isalphanumunder(eq_str(indx-1))) = [];
不知道为什么错误,MATLAB看不懂我写什么吧,不懂我要做什么!感慨啊!我都鼓捣好几天了,还是不会写!
请前辈高手们指点一下吧!万分感激!急盼回复啊!~~~~(>_<)~~~~