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Displaying 20 results from an estimated 2000 matches similar to: "(no subject)"

2004 Feb 23
1
dendrogram ultrametrics
Dear R-help listers, Is anyone aware of a function that outputs dendrogram ultrametrics? Cheers, Lisa. PS please reply to me personally as well as to the list because the website wasn't letting me subscribe for some reason. thanks... Lisa Holman Research Officer, Vegetation Dynamics Policy & Science Division NSW Department of Environment & Conservation PO Box 1967, Hurstville 2220.
2007 Aug 28
1
subcripts on data frames (PR#9885)
I'm not sure if this is a bug, or if I'm doing something wrong. =20 =46rom the worms dataframe, which is at in a file called worms.txt at =20 http://www.imperial.ac.uk/bio/research/crawley/therbook <http://www.imperial.ac.uk/bio/research/mjcraw/therbook/index.htm>=20 =20 the idea is to extract a subset of the rows, sorted in declining order of worm density, with only the maximum
2008 Jul 06
1
What is my replication unit? Lmer for binary longitudinal data with blocks and two treaments.
First I would like to say thank you for taking the time to read it.Here is my problem. I am running a lmer analysis for binary longitudinal (repeated measures) data. Basically, I manipulated fruits and vegetation to two levels each(present and absent) and I am trying to access how these factors affect mice foraging behavior. The design consist of 12 plots, divided in 3 blocks. So each block
2010 Oct 24
1
best predictive model for mixed catagorical/continuous variables
Would anybody be able to advise on which package would offer the best approach for producing a model able to predict the probability of species occupation based upon a range of variables, some of them catagorical (eg. ten soil types where the numbers assigned are not related to any qualitative/quantitative continuum or vegetation type) and others continuous such as field size or vegetation height.
2009 Dec 13
0
cross validation/GAM/package Daim
Dear r-helpers, I estimated a generalized additive model (GAM) using Hastie's package GAM. Example: gam1 <- gam(vegetation ~ s(slope), family = binomial, data=aufnahmen_0708, trace=TRUE) pred <- predict(gam1, type = "response") vegetation is a categorial, slope a numerical variable. Now I want to assess the accurancy of the model using k-fold cross validation. I found the
2010 May 26
1
Fill a matrix using logical arguments?
Hello all, I am going slightly mad trying to create a table for running co-correspondence analysis. What I have is seed bank and vegetation data, and my aim is to see if the vegetation found in a site (containing several seed bank samples) can predict the composition of a seed bank sample within that site. So for this I need two tables with matching rows. I have created an empty matrix,
2010 Nov 12
1
repeated measure test
Hi, This is a question regarding technique rather than an R specific issue. I have been asked to evaluate a 30+ year long term continuous survey of bird presence/absence data that has an associated ocular estimate of the vegetation community percent coverage. The data are organized by subpopulations (5), and by year ( 1991 - present). We are interested in gaining understanding on whether bird
2008 Jul 11
0
GroupedData for three way randomized block. LME
I am trying to fit a formula to my data, but I just can't find the right way to do it. My experiment consists of manipulating FRUITS and VEGETATION to two levels each(intact or removed) on 12 experimental plots. This leaves me with 4 treatment combinations Fruit intact Vegetation removed Fruit int. Veget int. Fruit rem. Veget rem. Fruit rem. Veget. intac those treatements are distributed
2011 Sep 23
0
vegan rda na adaptation
Dear R users, I know, the topic is more related to the r-sig-ecology. I decided to post it to the r-help as some specific topics of my question deals with NA-values and RDA (R vegan) and an adaptated RDA code due to a specific study design (including a second matrix). I am calculating a RDA for a dependent matrix (different variables for tree performance) and different explanatory
2008 Jul 19
1
wroung groupedData despite reading Bates and Pinheiro 3 times
Hi everyone. I am trying to add a formula to my data using the groupedData function. My experiment consists of randomized block design using fruits, vegetation and time as factors. The idea is to see if fruits, vegetation and time explain the abundance of mice. I am using tree density as a covariate. So I tried to fit the following structure to my data. >
2012 Oct 04
4
Creating vegetation distance groups from one column
Hi R listers, I am trying to group distances of nests to the vegetation into classes that are define by (0-5m, 6-10m, 11-15m, 16-20m, 21-25m, 26-30m, 31-35m, 36-40m, 41-45m, 46-50m, 51-55m, 56-60m). Each row is a nest and all the distances to the vegetation is in a column. In plyr, I have tried - below script but I think I am going about this the wrong way and am not successful. #Veg index
2007 Sep 05
1
ecological meaning of randomForest vegetation classification?
Hi, everyone, I haven't found anything similar in the forum, so here's my problem (I'm no expert in R nor statistics): I have a data set of 59.000 cases with 9 variables each (fractional coverage of 9 different plant types, such as deciduous broad-leaved temperate trees or evergreen tropical trees etc.), which was generated by a vegetation model. In order to evaluate the quality of
2001 Nov 13
0
VEGAN: R functions for vegetation ecologists
A colleague has just passed me this interesting address: http://cc.oulu.fi/~jarioksa/softhelp/vegan.html "Vegan: R functions for vegetation ecologists" "Vegan package is intended to help vegetation ecologists and other community ecologists to use R. It is not a completely self-contained package, but it complements other R functions. .../... At this first stage, vegan implements
2006 Jul 21
2
rpart unbalanced data
Hello all, I am currently working with rpart to classify vegetation types by spectral characteristics, and am comming up with poor classifications based on the fact that I have some vegetation types that have only 15 observations, while others have over 100. I have attempted to supply prior weights to the dataset, though this does not improve the classification greatly. Could anyone supply some
2008 Apr 18
2
Correspondence and detrended correspondence analysis
Hi, I hope someone knows the answer to this or has a real good reference about it (I am using Legendre & Legendre, Numerical Ecology, 1998).... My data is a data.frame with locations as rows and vegetation assemblages / species as columns. I've done a PCA, a correspondance analysis (CA) using ca in ca package and a detrended correspondance analysis (DCA) using decorana from vegan package.
2009 Apr 02
1
Time series analysis with irregular time-series
Dear R users I am currently investigating time series analysis using an irregular time series. Our study is looking at vegetation change in areas of alien vegetation growth after clearing events. The irregular time series is sourced from Landsat ETM+ data, over a six year period I have 38 scenes. For certain periods I have monthly data while for others, images are up to three months apart. So far
2012 Apr 14
2
master thesis
Hi, For my master thesis I have 24 micro-plots on which I did measurements during 3 months. The measurements were: - Rainfall and runoff events throughout 3monts (runoff being dependant on the rainfall, a coefficient (%) has been made per rainfall event and per 3 months) - Soil texture (3 different textures were differentiated) - Slope (3 classes of slopes) - Stoniness (one time measurement)
2008 Mar 04
1
simplifying a GLM-removing categorical variables
Hi, Thanks for reading this mesage! I have created a GLM (using the quasipoisson family) and am now trying to simplify it. One of my explanatory variables is categorical (vegetation type, with 6 different levels). In the model, 5 of the 6 levels are significant and one is not. How should I simplify my model? Do I need to take out the whole category (i.e. all of vegetation type), or just the
2009 Mar 09
1
rcorr.cens Goodman-Kruskal gamma
Dear r-helpers! I want to classify my vegetation data with hierachical cluster analysis. My Dataset consist of Abundance-Values (Braun-Blanquet ordinal scale; ranked) for each plant species and relev?. I found a lot of r-packages dealing with cluster analysis, but none of them is able to calculate a distance measure for ranked data. Podani recommends the use of Goodman and Kruskals' Gamma for
2006 Sep 12
1
Transformation of a data frame
Dear R-helpers, Apologies in advance for this (probably) simple question. I've searched the R Archive and can't seem to find a solution to my problem. I have a data frame of vegetation quadrat data with the following format: Q S C 1 A 5 1 B 10 1 C 50 1 D 10 2 A 20 2 E 10 2 C 40 3 D 5 3 F 1 3 G 5 3 B 75 Where Q is the sample (vegetation quadrats), S is the species and C is the