如何解决Matlab解决计算错误/求解器给出变量而不是数值答案的问题？

Question

我正在尝试求解q。但是，此错误出现在所附的图像中，我不知道如何修复它。代码在等式中没有第五个blob [k5 * z5 /（1 + q *（k5-1））]的情况下平稳运行，并且求解了q。但是，当我将其添加到方程式中时，会出现错误...帮助....

z1 = 0.01188354;

z2 = 0.20291147;

z3 = 0.03386809;

z4 = 0.6087344;

z5 = 0.1426025;

k1 = 0.00211577;

k2 = 433.816504;

k3 = 0.00651267;

k4 = 12.8652437;

k5 = 3.25E-06;

符号q

eqn = k1 * z1 /（1 + q *（k1-1））+ k2 * z2 /（1 + q *（k2-1））+ k3 * z3 /（1 + q *（k3-1 ））+ k4 * z4 /（1 + q *（k4-1））+ k5 * z5 /（1 + q *（k5-1））== 1;

qvalue = resolve（eqn，q，'Real'，true）

Answer 1

您对solve感到有些困惑。看来您的方程式没有真正的解决方案，您可以用'Real',true强制它应为：

z1 = 0.01188354;
z2 = 0.20291147;
z3 = 0.03386809;
z4 = 0.6087344;
z5 = 0.1426025;
k1 = 0.00211577;
k2 = 433.816504;
k3 = 0.00651267;
k4 = 12.8652437;
k5 = 3.25E-06;

syms q
eqn = k1*z1/(1+q*(k1-1)) + k2*z2/(1+q*(k2-1)) + k3*z3/(1+q*(k3-1)) + k4*z4/(1+q*(k4-1))+ k5*z5/(1+q*(k5-1)) == 1;
qvalue = solve(eqn,q)

输出为：

root(z^5 - (553951988707451897271725042874967932463648393519489496501295701298760653356885564069*z^4)/146344515065711958525050250689493211538989295698771861545387136571113311336350613504 + (877647369043978904163970290106419962713606423192038983322127636310825879207936*z^3)/164487327751721471763565140886077743965784030575734255347857322244873703346919 - (3796080934806054258394941458065140559250786119491250988496078448019381612969984*z^2)/1151411294262050302344955986202544207760488214030139787435001255714115923428433 + (838076006172751803233223399262272123114675605549658858976242221943722830987264*z)/1151411294262050302344955986202544207760488214030139787435001255714115923428433 + 21452770321210561747759866301918995558818778263453224281332504760441104236544/1151411294262050302344955986202544207760488214030139787435001255714115923428433, z, 1)
root(z^5 - (553951988707451897271725042874967932463648393519489496501295701298760653356885564069*z^4)/146344515065711958525050250689493211538989295698771861545387136571113311336350613504 + (877647369043978904163970290106419962713606423192038983322127636310825879207936*z^3)/164487327751721471763565140886077743965784030575734255347857322244873703346919 - (3796080934806054258394941458065140559250786119491250988496078448019381612969984*z^2)/1151411294262050302344955986202544207760488214030139787435001255714115923428433 + (838076006172751803233223399262272123114675605549658858976242221943722830987264*z)/1151411294262050302344955986202544207760488214030139787435001255714115923428433 + 21452770321210561747759866301918995558818778263453224281332504760441104236544/1151411294262050302344955986202544207760488214030139787435001255714115923428433, z, 2)
root(z^5 - (553951988707451897271725042874967932463648393519489496501295701298760653356885564069*z^4)/146344515065711958525050250689493211538989295698771861545387136571113311336350613504 + (877647369043978904163970290106419962713606423192038983322127636310825879207936*z^3)/164487327751721471763565140886077743965784030575734255347857322244873703346919 - (3796080934806054258394941458065140559250786119491250988496078448019381612969984*z^2)/1151411294262050302344955986202544207760488214030139787435001255714115923428433 + (838076006172751803233223399262272123114675605549658858976242221943722830987264*z)/1151411294262050302344955986202544207760488214030139787435001255714115923428433 + 21452770321210561747759866301918995558818778263453224281332504760441104236544/1151411294262050302344955986202544207760488214030139787435001255714115923428433, z, 3)
root(z^5 - (553951988707451897271725042874967932463648393519489496501295701298760653356885564069*z^4)/146344515065711958525050250689493211538989295698771861545387136571113311336350613504 + (877647369043978904163970290106419962713606423192038983322127636310825879207936*z^3)/164487327751721471763565140886077743965784030575734255347857322244873703346919 - (3796080934806054258394941458065140559250786119491250988496078448019381612969984*z^2)/1151411294262050302344955986202544207760488214030139787435001255714115923428433 + (838076006172751803233223399262272123114675605549658858976242221943722830987264*z)/1151411294262050302344955986202544207760488214030139787435001255714115923428433 + 21452770321210561747759866301918995558818778263453224281332504760441104236544/1151411294262050302344955986202544207760488214030139787435001255714115923428433, z, 4)
root(z^5 - (553951988707451897271725042874967932463648393519489496501295701298760653356885564069*z^4)