Dear Vladimir, You can use a logistic regression. First define Y0 as 30 - Y. Then Y is the number of days with headache and Y0 the number of days without. Then the model looks like: glm(cbind(Y, Y0) ~ X1 + X2 + X3, family = "binomial")
HTH, Thierry ------------------------------------------------------------------------ ---- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek team Biometrie & Kwaliteitszorg Gaverstraat 4 9500 Geraardsbergen Belgium Research Institute for Nature and Forest team Biometrics & Quality Assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 thierry.onkel...@inbo.be www.inbo.be To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey -----Oorspronkelijk bericht----- Van: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] Namens Vladimir Pekar Verzonden: vrijdag 15 januari 2010 11:26 Aan: r-help@r-project.org Onderwerp: [R] Best method Hi, I would like to ask for advice about best statistics method for my problem. I was done questionnaire about headache. My data are: Y - frequency of symptoms occur - times per month in range <0..30> (where 30 is daily and zero for never) and independent variables: X1 - sex - category {M,F} X2 - age - linear value X3 - type of work {administrative, manual, ...} ... Which model is "the best" for my problem: to describe weight of factors in equation "chance_to_present_symptom ~ variables": Y~X1+X2+X3 Y is not linear value with normal distribution. Y describe something like chance of to have symptom. I can't use linear regression, but something like logistic regression. Logistic is only for two (or more) Y value which is categorised not linear. Thank for any advice. -vladimir- ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. Druk dit bericht a.u.b. niet onnodig af. Please do not print this message unnecessarily. Dit bericht en eventuele bijlagen geven enkel de visie van de schrijver weer en binden het INBO onder geen enkel beding, zolang dit bericht niet bevestigd is door een geldig ondertekend document. The views expressed in this message and any annex are purely those of the writer and may not be regarded as stating an official position of INBO, as long as the message is not confirmed by a duly signed document. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.