Query about robust Aitchison in vegdist() and decostand() functions

[RachBioHaz]

Hi, I'm new to analysis. I am looking to use the robust Aitchison distance for my dissimilarity matrix. I was looking at the arguments and I wanted to know if I interpreted them correctly.

I was working through an example that used the "hellinger" to standardise the data, coupled with "euclidian" for distance:
hell_di <- vegdist(decostand(mite, method = "hellinger"), method = "euclidean")

I tried to do a similar thing with "rclr" and "robust.aitchison" and it didn't work. Not sure I've understood the documentation correctly, but am I right in thinking that I do not need to standardise the data in decostand if I am using "robust.aitchison" in vegdist?

Let me know if I am completely wrong in my interpretation.
Cheers

[antagomir]

You are correct.

The following two are equivalent (and x>0 always for clr):

vegdist(decostand(x, method = "clr"), method = "euclidean")
vegdist(x, method = "aitchison")

Similar thing applies to rclr and robust.aitchison.

[RachBioHaz]

Thank you