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I'm studying the NDVI (normalized vegetation index) behaviour of some soils and cultivars. My database has 33 days of acquisition, 17 kind of soils and 4 different cultivars. I have built it in two different ways, that you can see attached. I am having troubles and errors with both the shapes.

The question first of all is: Is repeated anova the correct way of analyzing my data? I want to see if there are any differences between the behaviours of the different cultivars and the different soils. I've made an ANOVA for each day and there are statistical differecies in each day, but the results are not globally interesting due to the fact that I would like to investigate the whole year behaviour.

The second question then is: how can I perform it? I''ve tryed different tutorials but I had unexpected errors or I didn't manage to complete the analysis.

Last but not the least: I'm coding with R Studio.

Any help is appreciated, I'm still new to statistic but really interested in improving!

orizzontal database vertical database

Rui Barradas
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Marco Prandi
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  • It's usually best not to give a picture of your data but the data itself, so that people can test their solutions to your problem. You can do so with `dput(DATANAME)`. – Érico Patto Apr 07 '21 at 12:25

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I believe you can use the ANOVA, but as always, you have to know if that really is what you're looking for. Either way, since this a plataform for programmin questions, I'll write a code that should work for the vertical version. However, since I don't have your data, I can't know for sure (for future reference, dput(data) creates easily importeable code for those trying to answer you).

summary(aov(suolo ~ CV, data = data))
Érico Patto
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  • thanks for the answer. I will upoload a small potion of my dataset if you need, but there are more then 120.000 records so i tought was too much. By the way, I was trying with `aov(ndvi ~ CV * suolo + Error(Day), data = d1)` because i want NDVI depending on CV and soil (suolo). I think my problems come from the generation of the model – Marco Prandi Apr 07 '21 at 18:17
  • In that case, keep in miand that CV is categorical and suolo is numerical. I'm no expert with statistical models, but the ANOVA I'm used to (as applied with `aov()`) can't handle that. – Érico Patto Apr 07 '21 at 20:49