similar to: Doubt about CCA and PCA

Displaying 20 results from an estimated 1000 matches similar to: "Doubt about CCA and PCA"

2008 Jul 01
3
reshape matrices
Hello everyone, I need reshape an array. For example, if we have next array: > a <- c(1,2,3,4,5,6,7,8,9,10,11,12) > dim(a) <- c(2,2,3) > a , , 1 [,1] [,2] [1,] 1 3 [2,] 2 4 , , 2 [,1] [,2] [1,] 5 7 [2,] 6 8 , , 3 [,1] [,2] [1,] 9 11 [2,] 10 12 I need to get next matrices: 1 2 3 4 5 6 7 8 9 10 11 12 1 3 2 4 5
2008 Jul 08
1
Help with eigenvectors
Hi everybody, I have some problems with the function eigen. I have a square matrix and I want to calculate the eigenvalues and eigenvectors. I apply the function eigen and I get it, however when I solve the same problem in Statistica software, I realise that some eigenvectors are the opposite. How can I get the same values? Thanks in advance [[alternative HTML version deleted]]
2013 Mar 27
1
Conditional CCA and Monte Carlo - Help!
Hi All, I am using canonical correspondence analysis to compare a community composition matrix to a matrix of sample spatial relationships and environmental variables. In order to parse out how much variance is explained purely by space (S/E) or the environment (E/S) I am using a conditional (partial) CCA. I want to test significance via Monte Carlo but I can not find a way to do this with a
2007 Jul 23
1
cca and cca.predict in vegan-what sort of prediction is possible
Hi All I am not clear quite how one could use cca from package vegan and the associated predict.cca to predict species abundance from environmental data (or if this is possible in a generalised way). In other words, can one derive a cca object based on known community data and use that to predict e.g. species abundances in a different number of samples based on environmental data? The help
2010 Aug 14
1
cca biplot (vegan) failed in matplot
Dear List, I am trying to plot the result of cca using matplot but failed. Pls kindly help and thanks. Elaine The error message was error in xy.coords(x, y, xlabel, ylabel, log = log) : (list) object cannot be coerced to type 'double' code rm(list=ls()) library(vegan) library(MASS) # input richness birdrich
2008 Sep 26
1
cca constraining variables table
I performed canonical correspondence analysis (cca) with the example data of vegan, but I'm not able to obtain a table like scores() for the constraining variables. I can see them in the summary() mode, but it would be great to have in a separate table. Any suggestion?, thanx Gianandrea require(vegan) data(varespec) data(varechem) vare.cca<-cca(varespec,varechem) scores(vare.cca)
2012 Nov 27
1
CCA plot
Hi, I have a couple questions about fitting environmental (land use factors, plant species presence-absence, and soil variables) constraints to my CCA biplot. 1. After successfully plotting species and site scores in my CCA, I have been trying to insert the biplot arrows of the environmental constraints in my data set using the text() function. When I do that, the plot changes completely. Is there
2010 Apr 27
1
cca standard error species
Dear all, I realised a correspondence analysis with function cca() of vegan library. Just like in Okansen (2010) in the example of R help: library(vegan) data(varespec) data(varechem) vare.cca<-cca(varespec~ Al + P + K, varechem) With plot.cca() function I represented the species matrix in the next way: plot(vare.cca,display="species") Being similar to: plot((c(-2,2)),(c(-2,2)),
2010 Jul 17
1
data.frame required for cca in ade4
Dear List, I tried to conduct cca using csv data but failed. The message said that data.frame is required. Please kindly share how to convert a csv-imported file to a data.frame. Thank you. Elaine code rm(list=ls()) spec <-read.csv("c:/migration/M_R_20100718_winterM_spec_vegan.csv",header=T, row.names=1) dim(spec) spec[1,] envi
2010 Jul 17
2
cca in vegan (formula instead of community matrix data)
Dear List, I tried to do cca based on species data and environmental variables (formula instead of community data). However, there was an error saying row sums must be >0. I searched the previous related messages but found few solutions. Please kindly help and thank you in advance. code This is vegan 1.17-3 Warning message: package 'vegan' was built under R version 2.10.1
2009 Sep 04
1
NA in cca (vegan)
Dear all, I would like to calculate a cca (package vegan) with species and environmental data. One of these environmental variables is cos(EXPOSURE). The problem: for flat releves there is no exposure. The value is missing and I can't call it 0 as 0 stands for east and west. The cca does not run with missing values. What can I do to make vegan cca ignoring these missing values? Thanks a lot,
2010 Aug 18
2
How to Perform CCA in ??!! Help please
Performing CCA in R I know they say don't say please... or plead...but I'm sorry but I really need some help with this problem. I have tried to perform CCA in R and I can never do this successfully. Can someone please tell me what I'm doing wrong. I can't attach any file...so Please email me and I'll attach the necessary files. (there's only two) the files will be my CCA R
2023 Dec 08
2
regarding CCA plot
Hii rstudio members I am learning rstudio, For my manuscript I am trying to plot CCA using species and environmental data. But I am getting error like Error in cca.default(sptrans, envtrans) : all row sums must be >0 in the community data matrix *My code is like * library(vegan) library(ggplot2) library(dplyr) rassspec<-read.csv("C:/Users/hp/Desktop/R_data/rassspec.csv",
2007 Apr 27
1
partitioning variation using the Vegan CCA routine?
Hello I am using Jari Oksanen's CCA routine from the Vegan package on some estuary data, following a technique applied in (Anderson, M.J. & Gribble, N.A., 1998, Partitioning the variation among spatial, temporal and environmental components in a multivariate data set, Australian Journal of Ecology 23, 158-167). Some steps in the process require that the dependent matrix be constrained by
2012 Nov 09
1
CCA with Vegan - Plot problem
Hi, I've just started using R and am having some problems with CCA using vegan. I'm looking at abundance p/m2 (hence decimals) vs environmental variables and have been using http://ecology.msu.montana.edu/labdsv/R/labs/lab12/lab12.html to guide me through. My organism data looks like this: Sample "Species_1" "Species_2" "Species_3" etc Sample_1
2010 Jul 17
1
cca in ade4
Dear List, I used spec and envi for cca in ade4. (both are data.frame) However, there is a message telling that error in if (nf > rank) nf <- rank R missing value in TRUE/FALSE Please kindly help how to modify the code below. Thank you. Elaine code rm(list=ls()) spec <-read.csv("c:/migration/M_R_20100718_winterM_spec_vegan.csv",header=T, row.names=1) dim(spec) spec[1,]
2013 Apr 05
2
transforming data prior to CCA
Hi everyone, I?m a student and relatively new to R so apologies in advance if this question seems stupid or obvious to you. I have collected a dataset with about 60 species of diatoms (count data from 19 different sample sites) and environmental variables for each site (salinity, pH, etc.). It?s all in the same dataset but distinct in R through the functions below diat <- diatom [, 1:60]
2009 Mar 20
1
CCA - manual selection
Hello, I am trying to obtain f-values for response (independent) variables from a CCA performed in vegan package, to see which ones of them have significative influence in my dependent variables (like the manual selection in canoco), but I can't find any function (or package) that do such a thing. The dependents variables are species data, and the independents are ambiental data. Than you.
2010 Sep 21
1
partial dbRDA or CCA with two distance objects in Vegan.
I am trying to use the cca/rda/capscale functions in vegan to analyse genetic distance data ( provided as a dist object calculated using dist.genpop in package adegenet) with geographic distance partialled out ( provided as a distance object using dist function in veganthis method is attempting to follow the method used by Geffen et al 2004 as suggested by Legendre and . FORTIN (2010). I
2011 Mar 10
1
vegan CCA I am Completely new to ordination analyses
Dear list, I am trying to predict species volume from bioclimatic data, I have various sites and I have a data frame with species volume and the corresponding bioclimatic data for each site. I read on a discussion forum that you can use ordination to predict species abundance (in my case volume) from 'new' climate data for sites where you do not know the abundance. Unfortunately I