search for: transects

Dear All, I would like to make partial sums (or means or any other function) of the values in intervals along a sequence (spatial transect) where groups are defined. For instance: habitats<-rep(c("meadow","forest","meadow","pasture"),c(10,5,12,6)) observations<-rpois(length(habitats),2)

Dear R friends, I have a matrix with 2060 rows and 41 columns. One column is Date, another is Transect, and another is Segment. I want to ensure that there are 9 Transects (1 to 9) for each Date, and 8 Segments (1 to 8) for each Transect in the matrix, by inserting rows where these are missing. I am new to coding, but am trying to write a loop which checks if each of the transects already exists, and then adds a row in the appropriate place if it doesn't (I ha...

I'm trying out a basic plot, but something about the way I subset my data leads to problems with the plot. Here is the first bit of my data set year,date,location,quadrat_juvenile,photo_location,photo_exists,genus,count,divers 2005,2005-04-30, 1 Fringing Reef,1, 1 Fringing Reef Coral Transect Pole 1-2 Quadrat 1,t,Acanthastrea,0,HP+MEM 2005,2005-04-30, 1 Fringing Reef,1, 1 Fringing Reef

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R-help readers, I''m having a problem with an R script (see below), which regularly generates the error message, Error in start:(start + (sample.length - 1)) : NA/NaN argument , for which I am unsure of the cause. In essence, the script (below) generates the start and end points for random subsamples from along a vector (in reality a transect (of a given length,

Hi all, I'm trying to fit models for data with three levels of nested random effects: site/transect/plot. For example, modelincrBS<-glmer(l.ru.ba.incr~shigo.av+pre.f.crwn.length+bark.thick.bh+Date+slope.pos.num+dens.T+dbh+leaf.area+can.pos.num+(1|site/transect/plot), data=rws30.UL, family=gaussian, na.action=na.omit) but I get the following error: Error: length(f1) == length(f2) is not

...ollowing glmm question (using glmmPQL from the MASS library): "We have two different forest habitats (first rotation thicket, and high forest) which we want to survey for the presence of our study animal. We survey both habitats on each of 10 days, and within each habitat we have five transects. The sampling unit is the number of animals counted per transect. We therefore have two sources of random variation: ? counts will vary between days due, say, to variation in weather ? counts will vary between transects, within sites, for any number of (known and unknown) reasons There i...

...9;lattices'(?) in the needed order, BUT the graphics # for the individual sets dump all the measurements into a single # cell, on the diagonal, as if it's treating the conditioning # variables as an [i,j] index. Again not what I want. # Draft code (incorrect data, correct layout): Transects <- c("LNF02", "LSF02", "LUR01", "LURT1", "LUR03", "LUR05", "LUR09", "LUR11", "LUR12", "LUR15", "LUR16", "LUR21", "LURT3", "...

...dlings within 1 meter on either side of the line. The end result was XY coordinates and height for ~1,300 seedlings. I would like to use that data to calculate density of seedlings per 10 meters per species and relative species abundance in order to compare between this transect and other transects as well as to compare between segments of the same transect. Are there any R packages out there that will allow me make those calculations? To give an idea of my data, here's a fictional example: Species X (m) Y(m) Acer negundo 90.10 -.19 Acer negundo 90.14 -.90 Acer saccharinum 9...

...t al. 2000. Analysis of count data from before-after control-impact studies. J. Agric. Biol. Envir Stat., 5:262-279) Data were collected from 1984, 1989, 1990, 1991, 1993, and 1996. Samples from 1984 are considered as before an impact and the remaining years as after the impact. Each year, 96 transects were sampled (36 in the oiled area and 60 in the non-oiled area; "0" is for oiled and "1" for non-oiled). The authors compare 3 different ways of analysing the data including glmm. The data can be reproduced with the following commands (density is fake numbers but I can prov...

Hi all, I'm trying to run a repeated measures ANOVA on some univariate ecological data that was collected over two growing seasons. I ran the test using the methodology found on this website: http://rtutorialseries.blogspot.com/2011/02/r-tutorial-series-one-way-repeated.html Upon running the actual ANOVA I got this error message: "> rmanova=anova(yearmodel, idata=yearframe,

Hello, I'm a final-year student in statistics and I deal with as subject of thesis "rare and elusive populations". I want make a simulation, in which I want generate a population and estimate its density with "line transect method" using R language. Is there someone that can send me the program that generate a population and estimate its density with "line transect

...9;lattices'(?) in the needed order, BUT the graphics # for the individual sets dump all the measurements into a single # cell, on the diagonal, as if it's treating the conditioning # variables as an [i,j] index. Again not what I want. # Draft code (incorrect data, correct layout): Transects <- c("LNF02", "LSF02", "LUR01", "LURT1", "LUR03", "LUR05", "LUR09", "LUR11", "LUR12", "LUR15", "LUR16", "LUR21", "LURT3", "...

Sub: using glmer to fit a mixed-effects model with gamma-distributed response variable Hello, I'm currently trying to fit a mixed effects model , i.e.: > burnedmodel1.2<-glmer(gpost.f.crwn.length~lg.shigo.av+dbh+leaf.area+ bark.thick.bh+ht.any+ht.alive+(1|site/transect/plot), family=gaussian, na.action=na.omit, data=rws30.BL) If I run this code, I get the error below: Error:

Dear R Community! We analyse the impact of climbing activity on cliff vegetation. During our fieldwork, we recorded 90 Transects in 3 climbing sites. The aim is to see, if the plant cover (response: Cover) is influenced only by crevice availability (predictor: Cracs), or, additional, by the distance to the climbing route (predictor: Distance). Six plots are nested within one Transect (ID.Transekt), the Transects are nested w...

...",..: 1 2 3 4 5 1 2 3 4 5 ... $ ts1 : Factor w/ 10 levels "Here 1","Here 2",..: 1 2 3 4 5 1 2 3 4 5 ... $ ts2 : Factor w/ 10 levels "Here 1","Here 2",..: 1 2 3 4 5 1 2 3 4 5 ... Might someone explain to me how I might reflect the fact that transects are different between sites, while days are not? #this does not work, though I thought it might be the best way to specify the model..... > GLMM(count~site,data=dat3,random=list(day=~1,trans=~1|site,family=poisso n) Error in GLMM(count ~ site, data = dat3, random = list(day = ~1, trans...

...g presences then the rows containing absences and combining them. e.g. presence_records<-sample(1:117,size=75,replace=FALSE) absence_records<-sample(118:936,size=549,replace=FALSE) ss<-c(presence_records,absence_records) but... b) My samples are within video transects and due to the risk of autocorrelation within each transect, ideally it is by transect cluster that they will be randomly selected. (a point within a transect cannot be allocated to the training dataset when another point from that same transect is already allocated to the test dataset) Is there a...

Hi, I have a question about computing shortest Euclidean distances between two data frames of spatial points... I have 2 dataframes (not yet converted to spatial class) >Sewers<-data.frame(x=c(10,20,35,50),y=c(100,150,200,300)) >transect <- data.frame(x=seq(from=0, to=50, by=1),y=seq(from=100, to=150, by=1)) I would like to be able to compute the shortest distance from the

Hi, I'm trying to analyse some data I have imported into R from a .csv file but when I carry out the aov command the results show only one degree of freedom when there should be 14. Does anyone know why? I'd really appreciate some help, the data is pasted below. /The imported table looks ike this this:/ Order Transect Sample Abundance 1 Coleoptera 1 1 13 2

Hi, We are analizing the relationship between the abundance of groupers in line transects and some variables. We are using the quasipoisson distribution. Do we need to include the length of the transects as an offset if they all have the same length?? Also, can we include in the gam models variables that are measured at different spatial scales? We have done an analysis to see what va...