| 5 | 1/1 | 返回列表 |
| 查看: 1691 | 回復(fù): 6 | |||
| 當(dāng)前只顯示滿足指定條件的回帖,點(diǎn)擊這里查看本話題的所有回帖 | |||
monixia木蟲 (小有名氣)
|
[求助]
求解決matlab解非線性方程組出現(xiàn)的問題 已有1人參與
|
||
|
各位matlab大神,我計(jì)算的方程組如下, >> m=0.00040; f=@(x)([3.14159*m^3+1.9635e-7*x(1)-0.002*3.14159*0.0005^2; 6*(m+x(2))*1.9635e-7-3.14159*m^3+1.9635e-7*x(3)+1.9635e-7*x(6)*(m+x(2))/x(4)-0.002*3.14159*0.0005^2; 3.14159*m^3*x(4)/(m+x(2))+1.9635e-7*x(1)*x(5)/(x(1)+x(3))-1/6*1e-6; (6*1.9635e-7*(m+x(2))-3.14159*m^3)*x(4)/(m+x(2))+1.9635e-7*x(3)*x(5)/(x(1)+x(3))+1.9635e-7*x(6)-1/6*1e-6; fix(0.05/(x(1)+x(3)))*(32*0.0010087*x(5)/0.0005^2*x(3)+7.16*0.07275*(3*(1.0087*x(5)/72.75)^(2/3)/0.0005/(1+3.34*(1.0087*x(5)/72.75)^(2/3))))-6455.68*x(6) 0.05/(m+x(2))*(32*0.0010087*x(4)/0.0005^2*x(2)+7.16*0.07275*(3*(1.0087*x(4)/72.75)^(2/3)/0.0005/(1+3.34*(1.0087*x(4)/72.75)^(2/3))))-6455.68*x(6)]); options = optimset('MaxIter',1e30,'MaxFunEvals',1e50,'TolFun',1e-50); x=fsolve(f,[0.005 0.0005 0.001 0.15 0.9 0.3],options) No solution found. fsolve stopped because the relative size of the current step is less than the default value of the step size tolerance squared, but the vector of function values is not near zero as measured by the selected value of the function tolerance. <stopping criteria details> x = 0.0070 -0.0001 0.0030 0.0344 1.0563 0.4352 fsolve stopped because the relative norm of the current step, 2.848645e-15, is less than max(options.TolX^2,eps) = 1.000000e-12. However, the sum of squared function values, r = 3.833839e-15, exceeds sqrt(options.TolFun) = 1.000000e-25. Optimization Metric Options relative norm(step) = 2.85e-15 max(TolX^2,eps) = 1e-12 (default) r = 3.83e-15 sqrt(TolFun) = 1.0e-25 (selected) 如上,初值已經(jīng)取的很接近實(shí)驗(yàn)值了,還是沒有滿意的結(jié)果。將matlab算的帶入六個(gè)方程, ans = 4.7168e-12 ans = -8.4160e-11 ans = 1.5716e-09 ans = -1.5222e-09 ans = 15.7955 ans = 232.7567 后兩項(xiàng)收斂不是很好。我已經(jīng)嘗試把optimset調(diào)到很小了,可是還是沒有滿意的結(jié)果。 求助各位大牛,這個(gè)該怎么解?還是方程需要修改? 如果圓滿解決,可以加金幣~ |
主管區(qū)長(zhǎng) (職業(yè)作家)
![]() |
專家經(jīng)驗(yàn): +1059 |

主管區(qū)長(zhǎng) (職業(yè)作家)
![]() |
專家經(jīng)驗(yàn): +1059 |

木蟲 (小有名氣)
主管區(qū)長(zhǎng) (職業(yè)作家)
![]() |
專家經(jīng)驗(yàn): +1059 |

| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 309求調(diào)劑 +17 | 誰(shuí)不是少年 2026-03-29 | 17/850 |
|
|---|---|---|---|---|
|
[考研] 一志愿武理材料工程302調(diào)劑環(huán)化或化工 +8 | Doleres 2026-03-31 | 8/400 |
|
|
[考研] 0856求調(diào)劑 +9 | 楒桉 2026-03-28 | 9/450 |
|
|
[考研] 070300一志愿211,312分求調(diào)劑院校 +12 | 小黃鴨寶 2026-03-30 | 12/600 |
|
|
[考研] 08開頭看過來(lái)。! +3 | wwwwffffff 2026-03-31 | 5/250 |
|
|
[考研] 318求調(diào)劑 +10 | 陳晨79 2026-03-30 | 10/500 |
|
|
[考研] 求調(diào)劑 +9 | akdhjs 2026-03-31 | 10/500 |
|
|
[考研] 322求調(diào)劑:一志愿湖南大學(xué) 材料與化工(085600),已過六級(jí)。 +10 | XX小鄧 2026-03-29 | 10/500 |
|
|
[考研] 340求調(diào)劑 +4 | 希望如此i 2026-03-31 | 4/200 |
|
|
[考研] 367求調(diào)劑 +7 | 芋泥啵! 2026-03-28 | 7/350 |
|
|
[考研] 274求調(diào)劑 +6 | xiao愛同學(xué) 2026-03-30 | 6/300 |
|
|
[考研] 359求調(diào)劑 +5 | 王了個(gè)楠 2026-03-25 | 5/250 |
|
|
[考研] 各位老師好,我的一志愿為北京科技大學(xué)085601材料專碩 +10 | Koxui 2026-03-28 | 10/500 |
|
|
[考研] 環(huán)境科學(xué)與工程334分求調(diào)劑 +6 | 王一一依依 2026-03-30 | 8/400 |
|
|
[考研] 085602 化學(xué)工程專碩 340分求調(diào)劑 +4 | qianbai11 2026-03-29 | 4/200 |
|
|
[考研] 348求調(diào)劑 +6 | 小懶蟲不懶了 2026-03-28 | 6/300 |
|
|
[考研] 085404求調(diào)劑,總分309,本科經(jīng)歷較為豐富 +6 | 來(lái)財(cái)aa 2026-03-25 | 6/300 |
|
|
[考研] 343求調(diào)劑085601 +3 | 要努力學(xué)習(xí)x 2026-03-29 | 3/150 |
|
|
[考研] 315分求調(diào)劑 +7 | 26考研上岸版26 2026-03-26 | 7/350 |
|
|
[考研] 材料與化工304求B區(qū)調(diào)劑 +3 | 邱gl 2026-03-25 | 3/150 |
|