| 5 | 1/1 | 返回列表 |
| 查看: 3290 | 回復(fù): 4 | ||||
[求助]
50金求解:關(guān)于lack-of-fit test的意義及應(yīng)用
|
|
我得到的標(biāo)準(zhǔn)曲線是用origin進(jìn)行線性擬合的,但審稿人說(shuō)加個(gè)lack-of-fit test,因?yàn)槲业膔值不太好。有位大神對(duì)我的數(shù)據(jù)用matlab進(jìn)行了test,,請(qǐng)見(jiàn)http://www.gaoyang168.com/bbs/viewthread.php?tid=4020335。但問(wèn)題是,我看不懂…… 我想請(qǐng)問(wèn):標(biāo)準(zhǔn)曲線是用origin進(jìn)行線性擬合的還是用lack-of-fit test得到的呢,帖子里的P值能說(shuō)明什么,應(yīng)該如何應(yīng)用,我看到直接給了個(gè)P值,但也有人用F值,真的不明白,想請(qǐng)教下,對(duì)下那位大神的數(shù)據(jù),我應(yīng)該如何應(yīng)用。 求解……急 我特意取了一些文獻(xiàn)的表達(dá),請(qǐng)見(jiàn)圖,我應(yīng)該用哪個(gè)好。 PS:我是做分析方法的。 |
榮譽(yù)版主 (著名寫手)
![]() |
專家經(jīng)驗(yàn): +4 |
|
見(jiàn)帖 http://en.wikipedia.org/wiki/Lack-of-fit_sum_of_squares http://www.gaoyang168.com/bbs/viewthread.php?tid=4020335&pid=7&page=1#pid7 LOFRTEST Lack-of-fit test for regression model with independent replicate values. LOFRTEST(D,alpha) is a statistical test that gives information on the form of the model under consideration. A significant lack-of-fit suggest that there may be some systematic variation unaccounted for in the hypothesized model (chosen model does not well describe the data). It arises when there are exact replicate values of the independent variable in the model that provide an estimate of pure error. Pure error is in essence the amount of error that cannot be accounted for by any model. Then allows a test on whether there is error present aside from pure error. For the construction of the lack-of-fit test we need to examine three common types of linear models: - single mean (one parameter) - slope and intercept or common regression model (two parameters) - separate means for each x-value or one-way ANOVA (many parameters). So, the pure error is the error of the separate means on ANOVA and the total error in the residual resulting in the regression analysis: the lack-of-fit results to be the difference between this two sources of error, SS(LOF) = SSR(Model) - SSE(ANOVA). Syntax: lofrtest(D,alpha) Inputs: D - matrix data (=[X Y]) (last column must be the Y-dependent variable). (X-independent variable entry can be for a simple [X], multiple [X1,X2,X3,...Xp] or polynomial [X,X^2,X^3,...,X^p] regression model). alpha - significance level (default = 0.05). Outputs: A complete summary (table) of analysis of variance partitioning sources of variation for testing lack-of-fit. Example from the data on height and weight of 19 students in Psy 202. Assigment 3 of Psych 3030 from the Department of Psychology of the York University. Available on Internet at the URL address http://www.psych.yorku.ca/lab/psy3030/assign/assign3.htm We are interested to test with a significance-value = 0.05 if there is a lack-of-fit on the regression model due to the height replicate values. ------------------- ------------------- Height Weight Height Weight ------------------- ------------------- 60 90 68 140 60 100 68 135 62 110 70 160 62 116 70 145 62 120 70 148 66 140 71 143 66 170 71 135 68 130 74 195 68 117 74 164 68 155 ------------------- ------------------- Data matrix must be: D=[60 90;60 100;62 110;62 116;62 120;66 140;66 170;68 130;68 117;68 155;68 140;68 135; 70 160;70 145;70 148;71 143;71 135;74 195;74 164]; Calling on Matlab the function: lofrtest(D) Answer is: Lack-of-fit test for regression model with independent replicate values. -------------------------------------------------------------------------- SOV SS df MS F P -------------------------------------------------------------------------- Model 7658.359 1 7658.359 31.720 0.0000 Residual 4104.378 17 241.434 -------------------------------------------------------------------------- Lack-of-fit 2142.011 5 428.402 2.620 0.0797 Pure error 1962.367 12 163.531 -------------------------------------------------------------------------- Total 11762.737 18 -------------------------------------------------------------------------- If the associated P-value for any F test is equal or larger than 0.05 The corresponding null hypothesis is met. Otherwise it is not met. Created by A. Trujillo-Ortiz, R. Hernandez-Walls, A. Castro-Perez and F.J. Marquez-Rocha Facultad de Ciencias Marinas Universidad Autonoma de Baja California Apdo. Postal 453 Ensenada, Baja California Mexico. atrujo@uabc.mx Copyright (C) March 4, 2005. To cite this file, this would be an appropriate format: Trujillo-Ortiz, A., R. Hernandez-Walls, A. Castro-Perez and F.J Marquez-Rocha. (2005). lofrtest:Lack-of-fit test for regression model with independent replicate values. A MATLAB file. [WWW document]. URL http://www.mathworks.com/matlabcentral/ fileexchange/loadFile.do?objectId=7074 References: Department of Psychology of the York University. Available on Internet at the URL address http://www.psych.yorku.ca/lab/psy3030/assign/assign3.htm Zar, J. H. (1999), Biostatistical Analysis (2nd ed.). NJ: Prentice-Hall, Englewood Cliffs. p. 345-350. |

榮譽(yù)版主 (著名寫手)
![]() |
專家經(jīng)驗(yàn): +4 |

新蟲(chóng) (小有名氣)
| 5 | 1/1 | 返回列表 |
| 最具人氣熱帖推薦 [查看全部] | 作者 | 回/看 | 最后發(fā)表 | |
|---|---|---|---|---|
|
[考研] 317分 一志愿南理工材料工程 本科湖工大 求調(diào)劑 +6 | 芋泥小鈴鐺 2026-03-28 | 6/300 |
|
|---|---|---|---|---|
|
[考研] 求調(diào)劑 +6 | 爭(zhēng)取九點(diǎn)睡 2026-03-28 | 6/300 |
|
|
[考研]
|
nnnnnnn5 2026-03-25 | 6/300 |
|
|
[考研] 311求調(diào)劑 +4 | 冬十三 2026-03-24 | 4/200 |
|
|
[考研] 070300求調(diào)劑306分 +4 | 26要上岸 2026-03-27 | 4/200 |
|
|
[考研] 266分,求材料冶金能源化工等調(diào)劑 +7 | 哇呼哼呼哼 2026-03-27 | 9/450 |
|
|
[考研] 286求調(diào)劑 +12 | PolarBear11 2026-03-26 | 12/600 |
|
|
[考研] 321求調(diào)劑 +6 | 璞玉~~ 2026-03-25 | 6/300 |
|
|
[考研] 339求調(diào)劑 +6 | 烤麥芽 2026-03-27 | 8/400 |
|
|
[考研] 289求調(diào)劑 +10 | 新時(shí)代材料 2026-03-27 | 10/500 |
|
|
[考研] 085600,材料與化工321分,求調(diào)劑 +9 | 大饞小子 2026-03-27 | 9/450 |
|
|
[考研] 348求調(diào)劑 +4 | 小懶蟲(chóng)不懶了 2026-03-27 | 5/250 |
|
|
[考研] 085601 材料工程 313分 求調(diào)劑 +5 | Ong3 2026-03-27 | 5/250 |
|
|
[考研] 材料學(xué)碩333求調(diào)劑 +8 | 北道巷 2026-03-24 | 8/400 |
|
|
[考研] 294分080500材料科學(xué)與工程求調(diào)劑 +4 | 柳溪邊 2026-03-26 | 4/200 |
|
|
[考研] 085600 材料與化工 329分求調(diào)劑 +9 | Mr. Z 2026-03-25 | 9/450 |
|
|
[考研] 一志愿天津大學(xué)339材料與化工求調(diào)劑 +3 | 江往賣魚(yú) 2026-03-26 | 3/150 |
|
|
[考研] 080500求調(diào)劑 +3 | zzzzfan 2026-03-24 | 3/150 |
|
|
[考博] 26申博自薦 +3 | whh869393 2026-03-24 | 3/150 |
|
|
[考研] 一志愿山東大學(xué)藥學(xué)學(xué)碩求調(diào)劑 +3 | 開(kāi)開(kāi)心心沒(méi)煩惱 2026-03-23 | 4/200 |
|