Hello everybody ! I want to evaluate the goodness of the fit of a trend surface. I use the Least square methods and the function surf.ls. The I write tma3.sur3 <- surf.ls(3, x, y, z) summary(tma3.sur3) Now the question: is the Pr(>F) the probability to obtain a value of F equal or greater than the obtained one ? Is the confidence level 0.05 ? Thanks a lot for any help. Paola. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
table of variance analysis
3 messages · Lecca Paola, Roger Bivand
On Thu, 21 Mar 2002, Lecca Paola wrote:
Hello everybody ! I want to evaluate the goodness of the fit of a trend surface. I use the Least square methods and the function surf.ls. The I write tma3.sur3 <- surf.ls(3, x, y, z) summary(tma3.sur3) Now the question: is the Pr(>F) the probability to obtain a value of F equal or greater than the obtained one ? Is the confidence level 0.05 ?
The value of Pr(>F) is the probability that a value of F of the size observed could have arisen under the null hypothesis of no relationship between z and the trend surface in the coordinates (x, y), given the assumptions made in the model. It is the same as in an anova() of a linear model object. Confidence levels and probability values are related, but not the same thing, perhaps a statistics textbook would help? Roger
Roger Bivand Economic Geography Section, Department of Economics, Norwegian School of Economics and Business Administration, Breiviksveien 40, N-5045 Bergen, Norway. voice: +47 55 95 93 55; fax +47 55 95 93 93 e-mail: Roger.Bivand at nhh.no and: Department of Geography and Regional Development, University of Gdansk, al. Mar. J. Pilsudskiego 46, PL-81 378 Gdynia, Poland. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Sorry in my previous message I express myself not well: I want to know if the limit for that the value of F is "reasonably probable" is 0.05. In other term, when can we say the the two distribution have a significative disagreement ? I suppose when Pr(>F) < 0.05. --Paola. -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._