search for: 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 some of the functionality of Peter Michin's DECODA w...

Hello R-user, sorry for this very off-topic question. But I shall present R to my dept. (pro's and con's and what it can do). The pro's and con's are easy but not what R can do (additional to the "normal" statistics). I looked through the packages, but the enormous amount of packages makes it very difficult for me to decide which one is worth mentioning. I used

Marine Spatial Modeler/Quantitative Ecologist position Full-Time/Exempt (Salaried) contract position with CSS-Dynamac (40 hrs per week) Job ID: 2016-1790 Location: Silver Spring, MD, USA; National Oceanic and Atmospheric Administration (NOAA) National Centers for Coastal Ocean Science (NCCOS) Posted Date: 11/29/2016 Category: Science/Engineering Security Clearance Level: National Agency Check

...ve a look at "Legendre & Legendre" text book. HTH, Miltinho Brazil David Farrar <dfarrar at newrvana.com> escreveu: In addition to the 25 numbers, I assume you have coordinates of each field. Otherwise, I don't understand what you are trying to do. I think ecologists like to use a test due to Mantel in this situation. The prefix "auto" means "self," of course, the idea being that measurements of the same variable under different conditions are correlated. I guess this would be a case of "autodependence." For correlation versus de...

The NOAA National Centers for Coastal Ocean Science is hiring a Computational Ecologist, a statistical/computational ecologist with experience fitting advanced spatial models to marine wildlife survey data (e.g., seabirds and marine mammal transects, fisheries trawl surveys) in R and other statistical languages. This is a full-time, long-term stable contract position. We are looking for an

Dear R user, I asked for packages which should be mentioned in a ecological related presentation of R and would like to summarize the replies. First of all E. Paradis pointed out, that he would prefer to see R presented in a different way, please read his whole reply https:// www.stat.math.ethz.ch/pipermail/r-help/2003-December/041951.html. Packages which

Greetings Though I have months in chronological order in my data table, the data were sampled every other month (i.e., February, April, June, August, October, December), every time I try to plot them (on the x-axis) they are plotted in alphabetical order. What am I missing? Cheers Kurt *************************************************************** Kurt Lewis Helf, Ph.D. Ecologist EEO

R-ecologists: Anyone wanting to create a Krebs package for R can do so using the C-source code avalaible at: ftp://gause.biology.ualberta.ca/pub/jbrzusto/krebs/source.zip Barry J. Cooke Current mailing address: Ph.D. Candidate 3971 NW 23 Circle Environmental Biology...

I have a data set of individual trees and the plots that they are in: Tree Plot 56749 1 63494 1 87375 1 37494 2 92753 3 34847 3 38747 4 etc... So each plot is represented once for every individual that occurrs in it. Plots get different numbers of rows because there can be a different number of individuals in each plot. I want to make a data frame that consists of one

I'm trying to obtain the mean of the middle 95% of the values from each row of a matrix (that is, the highest and lowest 2.5% of values in each row are removed before calculating the mean). I am having all sorts of problems with this; for example the command: apply(matrix1,1,function(x) quantile(c(.05,.90),na.rm=T)) returns the exact same quantile values for each row, which is clearly

Within a very large matrix composed of a mix of values and NAs, e.g, matrix A: [,1] [,2] [,3] [1,] 1 NA NA [2,] 3 NA NA [3,] 3 10 17 [4,] 4 12 18 [5,] 6 16 19 [6,] 6 22 20 [7,] 5 11 NA I need to be able to consecutively number, in new columns, the non-NA values within each column (i.e. A[1,1] A[3,2] and A[3,3] would all be set to one, and

Here's a question for ecologists on the r-help list-- I'm addressing this to ecologists in particular because they're most likely to be familiar with the equation in question but I'll be happy to discuss the problem with anyone who's willing to take a whack at it. I'm trying to write a function to calculate th...

Is there an R function that does canonical correspondence analysis. Can it be done using the VR function corresp()? If not, how hard it be to write R code to do it? I am a population biologist with long but patchy programming experience in C, Smalltalk, Java and other languages. Thanks, Patrick Foley patfoley at csus.edu

Dear Listers, I have a regression problem (x->y) with biological data, where x influences y in two ways, (1) y increases with x and (2) the variation around the mean (residuals) decreases with increasing x, i.e. y becomes more 'predictable' as x increases. The relationship is saturating, y~a + bx + cx^2, gives a very good fit. I know basically how to test for heteroscedasticity. My

Dear R users, I am using spatstat to analyze point patterns (tree locations). I would like to import the shapefile with the study area polygons (six total) into R and use it to create the window for the spatstat analysis. I do not simply want to use a rectangle because the study areas spread out over 40000 ha. Any suggestions would be greatly appreciated. Thanks, Charlotte Reemts Charlotte

I'm using R 1.6.2 on a Windows 2000 machine. I've plotted the results of an MDS run labeled by a numerical ID, and color coded by a group code: plot(cv.mds.spr$points, type="n", main="Non-Metric Multidimensional Scaling of SprRun CV Watersheds") text(cv.mds.spr$points, labels = as.character(cv.wshed.id.spr), col = codes(cv.wshed.grp), cex=.75) Question is, how do I

This has got to be incredibly simple but I nevertheless can't figure it out as I am apparently brain dead. I just want to convert the elements of a character vector to variable names, so as to then assign formulas to them, e.g: z = c("model1","model2"); I want to assign formulas, such as lm(y~x[,1]) and lm(y~x[,2]), to the variables "model1" and

Hi all I have produced a biplot for a PCA (see attached pdf) that I ran however the names of the variables which are placed at the end of the arrows overlap and are thus unreadable. Similarly some of the numbered points overlap. I was wondering if there was a way to edit the biplot to move the label names and if not what the best alternative is. Thanks Anna pca<-biodata[,3:10]

I realize this is probably pretty basic but I can't figure it out. I'm looping through an array, doing various calculations and producing a resulting data frame in each loop iteration. I need to give each data frame a different name. Although I can easily create a new character string for writing each frame to an output file, I cannot figure out how to convert such strings to

Dear all, I am trying to add a value to a dataframe and name the row with a number.? I have tried row.name, rowname, and attr(x,"row.names") but none seem to work.? It seems like it should be simple, so not sure why I can't get it to work.? Any suggestions? Thanks, Tim x<-seq(1,20,2) y<-seq(20,1,-2) xy<-data.frame(x,y) xy<-rbind(xy,c(0,0)) #Threeattempts that