system of equations fails to solve
2 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Matlab refuses to solve this system of equations despite certain other programs finding a single valid solution.
The original script:
syms x r C
eqn1 = 22.6==(x*((r^2+(1/(2*pi*5000*C)^2))^(1/2)))/(x+((r^2+(1/(2*pi*5000*C)^2))^(1/2)))
eqn2 = 19.1==(x*((r^2+(1/(2*pi*50000*C)^2))^(1/2)))/(x+((r^2+(1/(2*pi*50000*C)^2))^(1/2)))
eqn3 = 14.4==(x*((r^2+(1/(2*pi*500000*C)^2))^(1/2)))/(x+((r^2+(1/(2*pi*500000*C)^2))^(1/2)))
assume(C>0)
assume(x>0)
assume(r>0)
sol = solve(eqn1,eqn2,eqn3,x,r,C,'IgnoreAnalyticConstraints',1)
The errors:
Warning: Solutions are parameterized by the symbols: z, z1, z2. To include parameters and conditions in the solution,
specify the 'ReturnConditions' value as 'true'.
> In solve>warnIfParams (line 475)
In solve (line 357)
In failedscript (line 11)
Warning: Solutions are valid under the following conditions: 191/10 - (z*(z1^2 + 1/(10000000000*z2^2*pi^2))^(1/2))/(z
+ (z1^2 + 1/(10000000000*z2^2*pi^2))^(1/2)) == 0 & 0 < z & 0 < z1 & 0 < z2 & 72/5 - (z*(z1^2 +
4611686018427387904/(45515516623913202182151461698081*z2^2))^(1/2))/(z + (z1^2 +
4611686018427387904/(45515516623913202182151461698081*z2^2))^(1/2)) == 0 & 113/5 - (z*(z1^2 +
1/(100000000*z2^2*pi^2))^(1/2))/(z + (z1^2 + 1/(100000000*z2^2*pi^2))^(1/2)) == 0. To include parameters and
conditions in the solution, specify the 'ReturnConditions' value as 'true'.
> In solve>warnIfParams (line 482)
In solve (line 357)
In failedscript (line 11)
sol =
struct with fields:
x: [1×1 sym]
r: [1×1 sym]
C: [1×1 sym]
For simplicity the original equations are here:
0 Kommentare
Antworten (2)
Sindhu Karri
am 18 Mär. 2020
Hii,
It seems like the mathematical equations you code doesn't match with the original set of equations you provided. I urge you to recheck the equation once more. Although I wrote the code with the original equation and it seems to be working for me. You can refer to the following code. Also I recommend you to use vpasolve instead of solve function.
Code:
syms x r C
eq1=x+(1/(((1/r)^2+(2*3.14159*500*C)^2))^1/2)==22.6
eq2=x+(1/(((1/r)^2+(2*3.14159*50000*C)^2))^1/2)==19.1
eq3=x+(1/(((1/r)^2+(2*3.14159*500000*C)^2))^1/2)==14.4
assume(x>0)
assume(r>0)
assume(C>0)
sol=vpasolve(eq1,eq2,eq3,r,x,C)
1 Kommentar
Sindhu Karri
am 19 Mär. 2020
This seems to work
syms x r C
eq1=(x*(((1/r)^2+(2*3.14159*5000*C)^2))^1/2)/(x+((((1/r)^2+(2*3.14159*5000*C)^2))^1/2))==22.6
eq2=(x*((((1/r)^2+(2*3.14159*50000*C)^2))^1/2))/(x+((((1/r)^2+(2*3.14159*5000*C)^2))^1/2))==19.1
eq3=(x*((((1/r)^2+(2*3.14159*500000*C)^2))^1/2))/(x+((((1/r)^2+(2*3.14159*5000*C)^2))^1/2))==14.4
sol=vpasolve(eq1,eq2,eq3,r,x,C)
Siehe auch
Kategorien
Mehr zu Symbolic Math Toolbox finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!