calculate "dispersion index" (betadisper, vegan)
hi zoltan do you have another idea to calculate the dispersion? thanks Am 30.07.2015 07:52 schrieb Zoltan Botta-Dukat:
Hi Natalie, Be careful with convex hull volume, because it is zero if points lie on a line (an near to zero, if the configuration is close to this), independently from the amount of distances. Zoltan 2015.07.29. 19:26 keltez?ssel, Natalie ?rta:
hi all I would like to calculate a dispersion index or similar from the results of the vegan function betadisper. i would like to know if there is a possibility to e.g. calculate the volume of the community dispersion(area of the hull in the PCoA) from the betadisper results. common is to show the distance to the centroid.but I have the impression the dispersion within communities are not that clear,especially if you have similar variance. The program primer v5 calculates a disperion index based on the similarity percentage. similarity percentage is not an option since it is mainly based on most counted species. ideas and help are very much appreciated cheers natalie
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-- Botta-Duk?t Zolt?n -------------------------------- ?kol?giai ?s Botanikai Int?zet Magyar Tudom?nyos Akad?mia ?kol?giai Kutat?k?zpont -------------------------------- 2163. V?cr?t?t, Alkotm?ny u. 2-4. tel: +36 28 360122/157 fax: +36 28 360110 botta-dukat.zoltan at okologia.mta.hu www.okologia.mta.hu Zolt?n BOTTA-Duk?t -------------------------------- Institute of Ecology and Botany Hungarian Academy of Sciences Centre for Ecological Research -------------------------------- H-2163 V?cr?t?t, Alkom?ny u. 2-4. HUNGARY Phone: +36 28 360122/157 Fax..: +36 28 360110 botta-dukat.zoltan at okologia.mta.hu www.okologia.mta.hu
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