@ marwa can you please shed more insight to what you want to accomplish as there are functions in R associated to this, so as to give you the right one to use.

What about the merge()-function?

Ayobami Salau Ok, Thanks.

I want to create a barplot for the functional composition of my samples. The abundance data are stored in phyloseq object (Also could be written in a data frame). The rows represent taxa names, columns include samples and both taxonomic ranks and ecological guilds. More than one taxa have the same taxonomic ranks or ecological guild, so I need to merge such taxa at their guild to use the output to create barplot that reflects the different functional composition of samples.

For example, tax_glom() is a function that used to merge the taxa at specific taxonomic level (e.g phylum), so the taxa that belonged to the same phylum will be merged in one.

However, this function accepts only the 7 known taxonomic ranks (Kingdom, Phylum, class etc..).

Also, I would like to some statistical comparisons.

I hope it makes sense.

Sven Greving In which package??

It's in base R

https://www.rdocumentation.org/packages/base/versions/3.6.2/topics/merge

Sven Greving Thanks. merge() is used for merging data frames, but I want to merge different rows sharing the same value in a column in one data frame. Is it possible with merge()?

No, merge will not work here. Maybe you should check out aggregate then. However, I am not sure what it is, you want to "merge". Is it about the amount of observations, solely for the sake of barplots? Then you might want to check out plot functions such as ggplot2 for they incorporate aggregation across rows. If you wish to perform statistical analyses, you might want to consider aggregation however, but it depends on the packages/ analyses you want to employ.