ANOVA in R

sir please tell me how be find conclusion of this ANOVA problem

Hi! I conducted the ANOVA test in my data OK. In my case I have a treatment1+treatment2+treatment1*2 model, but when I try to the TukeyHSD and error says:
Error in `[.data.frame`(mf, mf.cols[[i]]) : undefined columns selectedI try to write the long version of the TukeyHSD, but with the same result. I think it´s not "reading" the data OK, I don´t know why it is doing the aov ok (I compared with other statistics software)
could you help me?

Hey Boone. Thanks for doing the videos. In the future, I recommend using generic datasets within R (e.g., Iris, cars, etc...) so that we can follow along with your analysis, instead of using unique datasetsthat are on your desktop. Thanks

Hi Jay T and thanks for watching the video. Your question is a bit vague for me to give you good advice. You can run many ANOVAs in the same code but I am a bit confused about how to tell you to go about it since you have 10 csv files and 4 different treatment groups. If you are trying to run a single ANOVA analysis then combine all 10 datasets into one file and then run the ANOVA on it for the 4 different treatment groups. If you have 10 distinct analysis then you would import each one of the files and do the ANOVA on each of those. Again... I wish I could help more but the description of your problem is a little too vague.

Is there a way to do multiple ANOVAs in one go? I currently have like 10 csv files and I am running ANOVAs on 4 groups for different treatments. Any advice would be much appreciated.

Hi, thanks for the video, now my questions are : Did you check normality of your data or homogenity of variances? Because normality of data and homogenity of variances are assumptions that must be clear before you use ANOVA. Now, is the data are only for illustrate sorry for my questions above.

Thanks man :).

My question is similar to msforytonly. If I have more than one response variable and two treatments how would I be able to run an Anova so that I can have one graph with all the variables?

Realy helped. One question left! what ist the exact definition of the relation between F value and P [Pr(>F)] ?????

This was really helpful - thank you very much!

Hello, your video was really helpful and clear thank you!

I was wondering if you might be able to help me, I am doing a cox ph on some data – which looks at the effect of a poor diet (8x sugar) and the genotype (3 in total – 2 control, 1 experimental) on the lifespan of drosophila. I’m using contrasts to compare my two controls vs the experimental group, and contrasts to compare the two controls.

I read I need to do an ANOVA before using contrasts (as it is wrong to direct which interactions to study after a study –so I need to show there is some deviation within the whole data first). However, I am finding it difficult to know how to do this.

Is it correct to do as you’ve shown:
anovad2<-aov(censor ~ genotype + weeks.on.8 + weeks.on.8:day.post.treatment + genotype: weeks.on.8 +  genotype:weeks.on.8:day.post.treatment, data= dilptwo23C)
summary(anovad2)

OR – I found that there is a cox zph anova function – but I don’t know if this is using an ANOVA of my data in the way I need it to?
dilptwofit23t1<-coxph(Surv(time=start, time2=day, event=censor)~ genotype + weeks.on.8 + weeks.on.8:day.post.treatment + genotype:weeks.on.8 +  genotype:weeks.on.8:day.post.treatment, data= dilptwo23C)
summary(dilptwofit23t1)
cox.zph(dilptwofit23t1)
anova(dilptwofit23t1)

I would be so grateful for any help – I’m getting so confused by these ANOVAs…
Thanks, 
Char

"So based on that P-value that is very very small by the way ... " where is the conclusion to that statement ? 

woohoo got it to work!! thanks for a video that was easy to follow!! 

Hi, this is a very useful video! can't believe how simple you made it!

How do I do a SD test using this anova?

How can I do a block ANOVA?

simple yet most helpful. Thank you so much

Thank you so much! I thought I was going mad because I couldn't do it! And it's so simple with your video!!! Thanks!!!!

thanq

thank you, i need this statistic thecnique to do research and it helped. also, you have a beer commercial voice that makes this more enjoyable

I am new to R. While in grad school I used stats programs that had more user friendly GUIs. I couldn't figure out how to retrieve the results of my anova. Thanks for the awesome video and the Tukey command was a plus.