| 查看: 1971 | 回復: 14 | ||||
dengwei_19木蟲 (著名寫手)
鐵齒金不換誠實可靠小郎君
|
[求助]
現(xiàn)在做到高斯函數(shù)的誤差函數(shù)一步,又是一個方程不知道用matlab怎么寫
|
|||
無機非金屬精華討論集 |
榮譽版主 (著名寫手)
![]() |
專家經(jīng)驗: +4 |
|
>> syms x >> syms w;int(exp(-x^2),0,w) ans = (pi^(1/2)*erf(w))/2 >> syms w;int(exp(-x^2),0,-w) ans = -(pi^(1/2)*erf(w))/2 =========== >> fun=@(x)-5.4*(pi^(1/2)*erf(10*2^0.5./x))/2-2.8*(pi^(1/2)*erf(40*2^0.5./x))/2+2.6; >> x=0.1:0.1:100; >> y=feval(fun,x); >> plot(x,y) >> [x,feval,flag]=fsolve(fun,80) Equation solved. fsolve completed because the vector of function values is near zero as measured by the default value of the function tolerance, and the problem appears regular as measured by the gradient. x = 81.4787 feval = -9.0775e-010 flag = 1 |

榮譽版主 (著名寫手)
![]() |
專家經(jīng)驗: +4 |

榮譽版主 (著名寫手)
![]() |
專家經(jīng)驗: +4 |
|
fun=@(x)-5.4*(pi^(1/2)*erf(10*2^0.5./x))/2-2.8*(pi^(1/2)*erf(40*2^0.5./x))/2+2.6; 這個是將你的積分方程式轉為誤差函數(shù),-(pi^(1/2)*erf(10*2^0.5./x))/2,(pi^(1/2)*erf(40*2^0.5./x))/2,是你的兩個積分 w(即x)的解使得fun=0 x=0.1:0.1:100; y=feval(fun,x); plot(x,y) 這個是w(即x)在0到100之間變化時fun的取值,用來在做圖猜測w大概在什么位置,fun=0 [x,feval,flag]=fsolve(fun,80)是用來求精確數(shù)值解 x解即w feval 取x的值 fun的函數(shù)值越接近0越好 flag 判斷解的情況 1 FSOLVE converged to a root. 2 Change in X too small. 3 Change in residual norm too small. 4 Computed search direction too small. 0 Too many function evaluations or iterations. -1 Stopped by output/plot function. -2 Converged to a point that is not a root. -3 Trust region radius too small (Trust-region-dogleg) or Regularization parameter too large (Levenberg-Marquardt). -4 Line search failed. |

金蟲 (職業(yè)作家)

木蟲 (著名寫手)
鐵齒金不換誠實可靠小郎君
鐵桿木蟲 (職業(yè)作家)
木蟲 (著名寫手)
鐵齒金不換誠實可靠小郎君
木蟲 (著名寫手)
鐵齒金不換誠實可靠小郎君
木蟲 (著名寫手)
鐵齒金不換誠實可靠小郎君
木蟲 (著名寫手)
鐵齒金不換誠實可靠小郎君
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 305分求調(diào)劑(食品工程) +4 | Sxy112 2026-03-21 | 6/300 |
|
|---|---|---|---|---|
|
[考研] 求調(diào)劑 +3 | 13341 2026-03-20 | 3/150 |
|
|
[考研] 0703化學297求調(diào)劑 +3 | Daisy☆ 2026-03-20 | 3/150 |
|
|
[考研] 材料 271求調(diào)劑 +5 | 展信悅_ 2026-03-21 | 5/250 |
|
|
[考研] 299求調(diào)劑 +5 | shxchem 2026-03-20 | 7/350 |
|
|
[考研] 279分求調(diào)劑 一志愿211 +14 | chaojifeixia 2026-03-19 | 15/750 |
|
|
[考研] 求調(diào)劑 +6 | Mqqqqqq 2026-03-19 | 6/300 |
|
|
[考研] 316求調(diào)劑 +6 | 梁茜雯 2026-03-19 | 6/300 |
|
|
[考研] 265求調(diào)劑 +3 | Jack?k?y 2026-03-17 | 3/150 |
|
|
[考研]
|
.6lL 2026-03-18 | 8/400 |
|
|
[考研] 308求調(diào)劑 +3 | 阿姐阿姐家啊 2026-03-18 | 3/150 |
|
|
[考研] 考研調(diào)劑求學校推薦 +3 | 伯樂29 2026-03-18 | 5/250 |
|
|
[考研] 一志愿 西北大學 ,070300化學學碩,總分287,雙非一本,求調(diào)劑。 +4 | 晨昏線與星海 2026-03-19 | 4/200 |
|
|
[考研] 一志愿西南交通 專碩 材料355 本科雙非 求調(diào)劑 +5 | 西南交通專材355 2026-03-19 | 5/250 |
|
|
[考研]
|
簡木ChuFront 2026-03-19 | 8/400 |
|
|
[考研] 0703化學調(diào)劑 +4 | 18889395102 2026-03-18 | 4/200 |
|
|
[考研] 材料,紡織,生物(0856、0710),化學招生啦 +3 | Eember. 2026-03-17 | 9/450 |
|
|
[考博] 26博士申請 +3 | 1042136743 2026-03-17 | 3/150 |
|
|
[考研] 有沒有道鐵/土木的想調(diào)劑南林,給自己招師弟中~ +3 | TqlXswl 2026-03-16 | 7/350 |
|
|
[論文投稿] 有沒有大佬發(fā)小論文能帶我個二作 +3 | 增銳漏人 2026-03-17 | 4/200 |
|