# There is an error when I performed chisquare and postanova test...:(

5 messages
Open this post in threaded view
|

## There is an error when I performed chisquare and postanova test...:(

 I am studying for a quiz and while I was solving two problems, an error occured. a) So the problem is we want to test if the block program makes a difference in retention at α = 1% (which is the significance level) This is the code I used to perform chisquare test. My solution: blockprogram <- matrix(c(18,15,5,8,4,10,5,7,18,10), nrow=2, byrow=T) colnames(blockprogram) <- c("1 yr","2 yr","3 yr","4 yr","5+ yrs") rownames(blockprogram) <- c("Non-Block","Block") chisq.test(blockprogram, conf.level=0.99) ==> This is the part where I can't run.. chisq.test(blockprogram, conf.level=0.99)\$observed chisq.test(blockprogram, conf.level=0.99)\$expected So my question is is it the conf.level=0.99 where it is wrongly used? b)I was able to run the one way anova but wasn't able to run on the tukey's test. I seriously do not know what went wrong... So, this is the original problem: The data set chicken.csv contains weights of chickens which are given 1 of 3 different food rations. Perform an ANOVA procedure to determine if the weights of the chickens are significantly affected by the food rations they are provided. In case a significant effect exists, perform a Tukey HSD post-hoc procedure to identify under which ration the chickens will be heaviest. Use a 5% level of significance. SO here's the code I used to perform: chicken <- read.csv("C:/Users/Win/Desktop/chicken.csv") attach(chicken) anova(lm(chicken\$ration~chicken\$weight)) anova.ration <- aov(chicken\$ration~chicken\$weight) posthoc.ration <- TukeyHSD(anova.ration, 'weight', conf.level=0.95) => This is the part where I wasn't able to run :(tapply(ration,weight, mean, na.rm=T) plot(posthoc.weight) Thanks!
Open this post in threaded view
|

## Re: There is an error when I performed chisquare and postanova test...:(

 Dear massmatics The list has a no homework policy but in this case I feel I can depart from that. Have you tried reading the documentation for chisq.test? On 25/09/2015 12:44, massmatics wrote: > I am studying for a quiz and while I was solving two problems, an error > occured. > a) So the problem is we want to test if the block program makes a difference > in retention at α = 1% > (which is the significance level) > This is the code I used to perform chisquare test. > My solution: > blockprogram <- matrix(c(18,15,5,8,4,10,5,7,18,10), nrow=2, byrow=T) > colnames(blockprogram) <- c("1 yr","2 yr","3 yr","4 yr","5+ yrs") > rownames(blockprogram) <- c("Non-Block","Block") > chisq.test(blockprogram, conf.level=0.99) ==> This is the part where I can't > run.. > chisq.test(blockprogram, conf.level=0.99)\$observed > chisq.test(blockprogram, conf.level=0.99)\$expected > So my question is is it the *conf.level=0.99* where it is wrongly used? > > b)I was able to run the one way anova but wasn't able to run on the tukey's > test. I seriously do not know what went wrong... So, this is the original > problem: > The data set chicken.csv contains weights of chickens which are given 1 of 3 > different food rations. Perform an ANOVA procedure to determine if the > weights of the chickens are significantly affected by the food rations they > are provided. In case a significant effect exists, perform a Tukey HSD > post-hoc procedure to identify under which ration the chickens will be > heaviest. Use a 5% level of significance. > > SO here's the code I used to perform: > chicken <- read.csv("C:/Users/Win/Desktop/chicken.csv") > attach(chicken) > anova(lm(chicken\$ration~chicken\$weight)) > anova.ration <- aov(chicken\$ration~chicken\$weight) > *posthoc.ration <- TukeyHSD(anova.ration, 'weight', conf.level=0.95) => This > is the part where I wasn't able to run :(* > tapply(ration,weight, mean, na.rm=T) > plot(posthoc.weight) > > Thanks! > > > > > -- > View this message in context: http://r.789695.n4.nabble.com/There-is-an-error-when-I-performed-chisquare-and-postanova-test-tp4712770.html> Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > [hidden email] mailing list -- To UNSUBSCRIBE and more, see > 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. > -- Michael http://www.dewey.myzen.co.uk/home.html______________________________________________ [hidden email] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
Open this post in threaded view
|

## Re: There is an error when I performed chisquare and postanova test...:(

 Yes, so far, we only learned how to use chisq.test when performed at 0.05 significance level But not when it is at 0.01