syms y(x) R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6; Cwall = 1.86e8; PN = 8; qout = 0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)diff(y,x,1)+1/R1/R2/Cin/Cwally==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; a=diff(y); cond = [eqn(0)==0, a==0]; ySol(x) = dsolve(eqn, cond);报错
时间: 2024-02-10 17:10:53 浏览: 83
Fourier-Motzkin Elimination:Fourier-Motzkin 消除不等式系统 (A*x <= b)。-matlab开发
您在修改代码时,仍然遗漏了初始条件。在这个微分方程中,需要提供y(0)和y'(0)的值。以下是修正后的代码:
```
syms y(x) R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6; Cwall = 1.86e8; PN = 8; qout = 0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)*diff(y,x,1)+1/R1/R2/Cin/Cwall*y==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; a=diff(y); cond = [y(0)==0, subs(a,x,0)==0]; ySol(x) = dsolve(eqn, cond);
```
请注意,这个微分方程可能不是初值问题,因为它只给出了一个初始条件。如果您需要唯一解,请提供另一个初始条件或边界条件。
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