search for: vincenzi

...tions of yield and values of the environmental variables. I'm wondering if it is feasible or if the number of observation is too low, if some data transformation is needed and which R function is the most appropriate to try to estimate the weights. Any help would be greatly appreciated. Simone Vincenzi _________________________________________ Simone Vincenzi, PhD Student Department of Environmental Sciences University of Parma Parco Area delle Scienze, 33/A, 43100 Parma, Italy Phone: +39 0521 905696 Fax: +39 0521 906611 e.mail: svincenz at nemo.unipr.it --

...r related covariates. b) we have two independent models, where the first part is a binary outcome model and the second one is a negative binomial model, assuming that zeros arise from a single process and set of covariates, as proposed by Dobbie and Welsh (Austr.N.Z.J.Stat., 2001) Thanks Simone Vincenzi PhD student in Ecology, University of Parma, Italy _________________________________________ Simone Vincenzi, PhD Student Department of Environmental Sciences University of Parma Parco Area delle Scienze, 33/A, 43100 Parma, Italy Phone: +39 0521 905696 Fax: +39 0521 906611 e.mail: svincenz...

...stream-specific fish densities are significantly different. I don't think I can use a straight t-test due to the problem of autocorrelation and I don't think I can use a repeated measure ANOVA as I don't have any replicates. Any help would be greatly appreciated. Thanks Simone Vincenzi -- Universita' degli Studi di Parma (http://www.unipr.it)

...test is: are mean densities different among streams from 2000 to 2007? Is it sufficient and appropriate a test of correlation (using rcorr of the library Design, for example) to test if density trends in time are similar among streams? Any help would be greatly appreciated. Simone Simone Vincenzi, PhD Department of Environmental Sciences University of Parma [[alternative HTML version deleted]]