search for: understory

Displaying 3 results from an estimated 3 matches for "understory".

2008 Jan 09
0
formating ftable
Hi all, I am using ftable and xtabs to get total counts of species per location per hight category (understory, midstory and overstory). i can save the data in almost the format i would like it to be - but not quite. Here it is an example of what i get: x - is a dataframe with the following columns: LocationID, Species, PercentCover, Category where Category tells if the Species belongs to understory, mids...
2008 Jan 10
0
formatting ftable
Hi all, I am using ftable and xtabs to get total counts of species per location per hight category (understory, midstory and overstory). i can save the data in almost the format i would like it to be - but not quite. Here it is an example of what i get: x - is a dataframe with the following columns: LocationID, Species, PercentCover, Categorywhere Category tells if the Species belongs to understory, midstor...
2010 Mar 20
5
Problem specifying Gamma distribution in lme4/glmer
Dear R and lme4 users- I am trying to fit a mixed-effects model, with the glmer function in lme4, to right-skewed, zero-inflated, non-normal data representing understory grass and forb biomass (continuous) as a function of tree density (indicated by leaf-area). Thus, I have tried to specify a Gamma distribution with a log-link function but consistently receive an error as follows: > total=glmer(total~gla4+(1|plot)+(1|year/month),data=veg,family=Gamma(link=log)...