Symbolic rewritten in matlab
1 ビュー (過去 30 日間)
表示 古いコメント
alpha=log(r)/t0/(r-1);
beta=r*log(r)/t0/(r-1);
p0=p*(exp(-alpha*t)-exp(-beta*t))/(exp(-alpha*t0)-exp(-beta*t0));
%r=?
%I tried this, plug alpha and beta with the expressions
syms r t p p0 t0
alpha=log(r)/t0/(r-1);
beta=r*log(r)/t0/(r-1);
%p0=p*(exp(-(log(r)/t0/(r-1))*t)-exp(-(r*log(r)/t0/(r-1))*t))/(exp(-(log(r)/t0/(r-1))*t0)-exp(-(r*log(r)/t0/(r-1))*t0));
eqn=(p*(exp(-(log(r)/t0/(r-1))*t)-exp(-(r*log(r)/t0/(r-1))*t))/(exp(-(log(r)/t0/(r-1))*t0)-exp(-(r*log(r)/t0/(r-1))*t0))==p0);
r=solve(eqn,[t, p, p0 t0])
%It doesn't give what I want
Hello, I have a equation, p0= above
I want to rewrite it as r=something
how can I do this in MATLAB or any other website?
1 件のコメント
Walter Roberson
2022 年 6 月 21 日
You cannot solve one equation for four variables. You should be trying
solve(eqn, r)
採用された回答
Star Strider
2022 年 6 月 21 日
An analytic solution is likely not possible, due to the nature of the expression.
The only option is to solve it numerically for ‘r’ given appropriate values for the other variables —
syms p p0 r t0 t
alpha=log(r)/t0/(r-1);
beta=r*log(r)/t0/(r-1);
Eqn = p0 == p*(exp(-alpha*t)-exp(-beta*t))/(exp(-alpha*t0)-exp(-beta*t0))
p0fcn = matlabFunction(rhs(Eqn)-p0)
p = rand;
p0 = rand;
t = rand;
t0 = rand;
r = fsolve(@(r)p0fcn(p,p0,r,t,t0), rand)
.
0 件のコメント
その他の回答 (0 件)
参考
カテゴリ
Find more on Numbers and Precision in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!