Post hoc comparisons such as tukey compare between groups. U have to tell R that station is a grouping variable i.e. station needs to be a factor. I'm guessing U have entered station as a number, meaning R thinks it’s a continuous variable like temperature.
The give away is the 1 DF for station in your ANOVA table. I suggest u convert station to a factor like so: stationf <- factor(station) and then fit the model aov(zoo~stationf) Chris Howden B.Sc. (Hons) GStat. Founding Partner Evidence Based Strategic Development, IP Commercialisation and Innovation, Data Analysis, Modelling and Training (mobile) 0410 689 945 (fax) +612 4782 9023 [email protected] Disclaimer: The information in this email and any attachments to it are confidential and may contain legally privileged information. If you are not the named or intended recipient, please delete this communication and contact us immediately. Please note you are not authorised to copy, use or disclose this communication or any attachments without our consent. Although this email has been checked by anti-virus software, there is a risk that email messages may be corrupted or infected by viruses or other interferences. No responsibility is accepted for such interference. Unless expressly stated, the views of the writer are not those of the company. Tricky Solutions always does our best to provide accurate forecasts and analyses based on the data supplied, however it is possible that some important predictors were not included in the data sent to us. Information provided by us should not be solely relied upon when making decisions and clients should use their own judgement. -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Mahnaz Rabbaniha Sent: Thursday, 28 February 2013 6:05 PM To: r-sig-ecology Subject: [R-sig-eco] anova Dear all hi may be my question is very basically: I want to compare between zooplankton density in 36 station. In base of shapiro.test and normality of data, i choose anova but when apply TukeyHSD i take mis message. any person help me what is meaning?? > shapiro.test(f) Shapiro-Wilk normality test data: f W = 0.9081, p-value = 0.1084 > model1<-aov(zoo~STATION) > summary(model1) Df Sum Sq Mean Sq F value Pr(>F) STATION 1 1.2055e+09 1205487359 0.3803 0.5384 Residuals 157 4.9771e+11 3170152766 > TukeyHSD(model1) Error in TukeyHSD.aov(model1) : no factors in the fitted model In addition: Warning message: In replications(paste("~", xx), data = mf) : non-factors ignored: STATION > -- Mahnaz Rabbaniha marine ecology PhD Iranian Fisheries Research Organization (IFRO) P.O.Box: 14155-6116 , P.Code: 1411816618* Tehran, IRAN Phone: +98 21 44580953 Fax: +98 21 44580583 Mobile: +98 912 5790377 [[alternative HTML version deleted]] _______________________________________________ R-sig-ecology mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-ecology _______________________________________________ R-sig-ecology mailing list [email protected] https://stat.ethz.ch/mailman/listinfo/r-sig-ecology
