| 查看: 4406 | 回復(fù): 15 | |||
xiangzigood新蟲(chóng) (初入文壇)
|
[求助]
matlab fsolve得出的解全部為復(fù)數(shù)解
|
|
我用matlab中的FSOLVE解一個(gè)六元非線性方程組,為什么得出的解全部為復(fù)數(shù)解,可是理論上應(yīng)該解為實(shí)數(shù),本人Matlab新手,代碼如下,大神們幫忙看一下吧! function[x,x0,fval,exitflag]=fsolveyalinjieliu d=0.045;D=0.05;k=1.4;ff=0.004;L=100;P1=1500000;T1=300;Pa=101325;M=29;R=8.314; x0=unifrnd(0,1,1,6); options=optimset('MaxFunEvals',20000,'MaxIter',5000); [x,fval,exitflag]=fsolve(@f,x0,options); function F=f(x) F=[((k+1)/2)*log((x(2)^2*x(3))/(x(1)^2*x(4)))-(1/(x(1)^2)-1/(x(2)^2))+4*ff*L/D; (d^2/D^2)*x(5)*sqrt((2*k*M)*((Pa/x(5))^(2/k)-(Pa/x(5))^((k+1)/k))/(R*x(6)*(k-1)))-x(2)*x(5)*sqrt((k*M)/(R*x(6))); (d^2/D^2)*x(5)*sqrt((2*k*M)*((Pa/x(5))^(2/k)-(Pa/x(5))^((k+1)/k))/(R*x(6)*(k-1)))-x(1)*P1*sqrt((k*M)/(R*T1)); 1+((k-1)*x(1)^2)/2-x(3); 1+((k-1)*x(2)^2)/2-x(4); ] end end |
鐵桿木蟲(chóng) (職業(yè)作家)
超級(jí)版主 (文學(xué)泰斗)
No gains, no pains.
![]() |
專家經(jīng)驗(yàn): +21105 |
新蟲(chóng) (初入文壇)
新蟲(chóng) (初入文壇)

新蟲(chóng) (初入文壇)
鐵桿木蟲(chóng) (職業(yè)作家)

新蟲(chóng) (初入文壇)
|
function[x,x0,fval,exitflag]=fsolveyalinjieliu d=0.04;D=0.05;k=1.4;ff=0.004;L=1000;P1=1500000;T1=300;Pa=101325;M=29;R=8.314; x0=unifrnd(0,1,1,6); options=optimset('MaxFunEvals',20000,'MaxIter',5000); [x,fval,exitflag]=fsolve(@f,x0,options); function F=f(x) F=[((k+1)/2)*log((x(2)^2*x(3))/(x(1)^2*x(4)))-(1/(x(1)^2)-1/(x(2)^2))+4*ff*L/D; (d^2/D^2)*sqrt(2*((Pa/x(5))^(2/k)-(Pa/x(5))^((k+1)/k))/(k-1))-x(2); (d^2/D^2)*x(5)*sqrt((2*k*M)*((Pa/x(5))^(2/k)-(Pa/x(5))^((k+1)/k))/(R*x(6)*(k-1)))-x(1)*P1*sqrt((k*M)/(R*T1)); 1+((k-1)*x(1)^2)/2-x(3); 1+((k-1)*x(2)^2)/2-x(4); x(6)-(x(3)*T1)/x(4); ] end end 這個(gè)應(yīng)該比較完整,六個(gè)方程六個(gè)未知數(shù) |
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 一志愿華中農(nóng)業(yè)071010,總分320求調(diào)劑 +5 | 困困困困坤坤 2026-03-20 | 6/300 |
|
|---|---|---|---|---|
|
[考研] 一志愿中南化學(xué)(0703)總分337求調(diào)劑 +9 | niko- 2026-03-19 | 10/500 |
|
|
[考研] 305分求調(diào)劑(食品工程) +4 | Sxy112 2026-03-21 | 6/300 |
|
|
[考研] 考研調(diào)劑 +4 | 來(lái)好運(yùn)來(lái)來(lái)來(lái) 2026-03-21 | 4/200 |
|
|
[考研] 354求調(diào)劑 +7 | Tyoumou 2026-03-18 | 10/500 |
|
|
[考研] 廣西大學(xué)材料導(dǎo)師推薦 +3 | 夏夏夏小正 2026-03-17 | 5/250 |
|
|
[考研] 求調(diào)劑 +3 | 13341 2026-03-20 | 3/150 |
|
|
[考研] 一志愿深大,0703化學(xué),總分302,求調(diào)劑 +4 | 七月-七七 2026-03-21 | 4/200 |
|
|
[考研] 299求調(diào)劑 +5 | shxchem 2026-03-20 | 7/350 |
|
|
[考研] 266求調(diào)劑 +3 | 哇呼哼呼哼 2026-03-20 | 3/150 |
|
|
[考研] 279分求調(diào)劑 一志愿211 +14 | chaojifeixia 2026-03-19 | 15/750 |
|
|
[考研] 330求調(diào)劑0854 +3 | assdll 2026-03-21 | 3/150 |
|
|
[考研] 南昌大學(xué)材料專碩311分求調(diào)劑 +6 | 77chaselx 2026-03-20 | 6/300 |
|
|
[考研] 070300化學(xué)319求調(diào)劑 +7 | 錦鯉0909 2026-03-17 | 7/350 |
|
|
[考研] 332求調(diào)劑 +4 | ydfyh 2026-03-17 | 4/200 |
|
|
[考研] 350求調(diào)劑 +5 | weudhdk 2026-03-19 | 5/250 |
|
|
[考研] 0856調(diào)劑,是學(xué)校就去 +8 | sllhht 2026-03-19 | 9/450 |
|
|
[考研] 材料學(xué)碩318求調(diào)劑 +5 | February_Feb 2026-03-19 | 5/250 |
|
|
[考研] 生物學(xué)調(diào)劑招人。! +3 | 山海天嵐 2026-03-17 | 4/200 |
|
|
[考研] 283求調(diào)劑 +3 | 聽(tīng)風(fēng)就是雨; 2026-03-16 | 3/150 |
|