similar to: line transect method

Displaying 20 results from an estimated 2000 matches similar to: "line transect method"

2011 Nov 12
1
Subsetting data leads to funky plots
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
2006 Feb 26
2
subtotal, submean, aggregate
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)
2003 Feb 12
1
Na/NaN error in subsampling script
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,
2011 Apr 28
1
using lme4 with three nested random effects
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
2010 Aug 13
1
loop for inserting rows in a matrix
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
2011 Nov 18
1
One-way repeated measures ANOVA
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,
2008 Aug 17
1
before-after control-impact analysis with R
Hello everybody, In am trying to analyse a BACI experiment and I really want to do it with R (which I find really exciting). So, before moving on I though it would be a good idea to repeat some known experiments which are quite similar to my own. I tried to reproduce 2 published examples but without much success. The first one in particular is a published dataset analysed with SAS by
2006 Sep 12
1
Using XY location data to calculate ecological parameters
Dear R gurus, I have XY data giving the locations of tree seedlings that were surveyed during a 210 meter belt transect. This belt transect was taken by stretching a line across the field, then measuring all seedlings 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
2011 May 13
1
using glmer to fit a mixed-effects model with gamma-distributed response variable
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:
2011 Sep 08
1
random sampling but with caveats!
Hi, I wonder if someone can help me. I have built a gam model to predict the presence of cold water corals and am now trying to evaluate my model by splitting my dataset into training/test datasets. In an ideal world I would use the sample() function to randomly select rows of data for me so for example with 936 rows of data in my HH dataset I might say ss <- sample(nrow(HH), size =
2011 Oct 09
3
ANOVA from imported data has only 1 degree of freedom
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
2008 Mar 20
1
minimum distances
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
2005 Jan 06
1
GLMM and crossed effects
Hi again. Perhaps a simple question this time.... I am analysing data with a dependent variable of insect counts, a fixed effect of site and two random effects, day, which is the same set of 10 days for each site, and then transect, which is nested within site (5 each). I am trying to fit the cross classified model using GLMM in lme4. I have, for potential use, created a second coding
2012 Jul 18
2
loop searching the id corresponding to the given index (timestamp)
Hello, I have the following loop for two data sets: diveData_2008 and diveData_2009. It uses two other data: diveCond_all and fishTable. The problem is at the point to identify the dive_id for the given index (index is timestamp). It keeps on saying for the1st loop Error in fishReport$dive_id[i] <- dive_id : replacement has length zero for the 2nd loop Error in fishReport$dive_id[i + j] <-
2009 Mar 23
1
Plot Means Line with Standard Deviation as "Whiskers"
Hi list members. I’ll try to plot the abundance means of nine transects as lines, with five points on each transect (A to I). I will also need to plot for each point, it’s standard deviation (once each point will have tree replicates) as whiskers. Another problem will be that all the points should exist for each transect, but we know that six of the nine transects will have blanks (A1, A2, A3, -,
2012 Jul 19
1
expert opinion on lmer
Hello, I have the following design, counts were collected at different transects, different depths and different sites at different times. Time is continuous and assumed to be random, all the others are categorical fixed where transect is nested within depth which is nested within site. I would like an expert opinion about the following code where intercept is modeled as random (I am not sure
2011 Mar 18
1
XYPlot Conditioning Variable in Specific, Non-Alphanumeric Order.
# I need to create an xyplot() where I control the specific order of # both my conditioning variables. The default code below plots the # data correctly (dispersed across all 14 columns), but fails in two # ways. Both the primary conditioning variable (Transect), and the # secondary conditioning variable (Offset) are in alphanumeric order, # rather than the specific order I need. # Here
2012 May 04
1
Medidas Repetidas
Hola a todos, Estoy intentando realizar un análisis de medidas repetidas en R y me gustaría pediros opinión porque estoy un poco atascada. Estoy utilizando las funciones lme y lmer. Tengo datos de censos de grillos (efi) realizados semanalmente (week) en tres parcelas (plot) diferentes, cada una de las cuales tiene seis transectos (transect) donde se realizan dichos censos. Los datos son de dos
2005 Jul 15
1
nlme and spatially correlated errors
Dear R users, I am using lme and nlme to account for spatially correlated errors as random effects. My basic question is about being able to correct F, p, R2 and parameters of models that do not take into account the nature of such errors using gls, glm or nlm and replace them for new F, p, R2 and parameters using lme and nlme as random effects. I am studying distribution patterns of 50 tree
2011 Mar 18
2
XYPlot Conditioning Variable in Specific, Non-Alphanumeric Order. -- Resending with corrected .txt file
Due to an error on my part, I have renamed the previously attached file from T_5-04b_LTC-SE-SO-Compared.csv to T_5-04b_LTC-SE-SO-Compared.txt. It remains a comma-delimited file so the extension can be changed and used per the script, or loaded separately. My sincere apologies, Guy -----Original Message----- From: Guy Jett Sent: Friday, March 18, 2011 1:13 PM To: 'r-help at