similar to: linear mixed-effects models with two random variables?

Displaying 20 results from an estimated 700 matches similar to: "linear mixed-effects models with two random variables?"

2012 Sep 11
0
how to perform multiple comparisons with anova.glm significant interactions?
Dear R users I want to evaluate my significant interactions among 3 predictors in glm (one is a factor and 2 are numeric indices). I had a 3rd order interaction in my anova.glm and I'm wondering how to investigate them. I read multcomp package but I found it difficult for me. #Say e.g. (I'm not using real values and in this e.g. does not have the interactions I'm saying - but my data
2005 Nov 10
2
IF/Else
Hi, I am trying to write a for loop with if else statements to calculate biomass density estimates for different types of sampling gear. My code is: bmd=for (i in 1:length(Gear)){ if (Gear==20) {bioden=Biomass/141} else {if (Gear==23) {bioden=Biomass/68}} else {if (Gear==160) {bioden=Biomass/4120}} else {if (Gear==170) {bioden=Biomass/2210}} else {if (Gear==300)
2011 Feb 06
1
anova() interpretation and error message
Hi there, I have a data frame as listed below: > Ca.P.Biomass.A P Biomass 1 334.5567 0.2870000 2 737.5400 0.5713333 3 894.5300 0.6393333 4 782.3800 0.5836667 5 857.5900 0.6003333 6 829.2700 0.5883333 I have fit the data using logistic, Michaelis?Menten, and linear model, they all give significance. > fm1 <- nls(Biomass~SSlogis(P, phi1, phi2, phi3), data=Ca.P.Biomass.A)
2013 Nov 07
1
problem with interaction in lmer even after creating an "interaction variable"
Dear all, I have a problem with interactions in lmer. I have 2 factors (garden and gebiet) which interact, plus one other variable (home), dataframe arr. When I put: / lmer (biomass ~ home + garden:gebiet + ( 1|Block), data = arr)/ it writes: /Error in lme4::lFormula(formula = biomass ~ home + garden:gebiet + (1 | : rank of X = 28 < ncol(X) = 30/ In the lmer help I found out that if not
2012 Feb 03
1
ordering of factor levels in regression changes result
I was surprised to find that just changing the base level of a factor variable changed the number of significant coefficients in the solution. I was surprised at this and want to know how I should choose the order of the factors, if the order affects the result. Here is the small example. It is taken from 'The R Book', Crawley p. 365. The data is at
2011 Apr 13
1
print to .jpeg
Evening folks, I'm trying to print a series of graphs to .jpeg using a variable as the title, but run into the difficultly that I can't find a way to append the file extension to the .jpeg (in this case extensionless!) files. Example: ---- species.name="CussoniaHolstii" dia<-10:100 biomass = -21.4863 + 0.5797 * (dia ^ 2) biomass jpeg(species.name) plot (biomass,
2009 Apr 01
3
How to prevent inclusion of intercept in lme with interaction
Dear friends of lme, After so many year with lme, I feel ashamed that I cannot get this to work. Maybe it's a syntax problem, but possibly a lack of understanding. We have growth curves of new dental bone that can well be modeled by a linear growth curve, for two different treatments and several subjects as random parameter. By definition, newbone is zero at t=0, so I tried to force the
2008 Feb 21
1
update don't find an object
Hi, I have a situation here. I try this update: mmaa <- update(mma,biomass~qvartemp) but I have this message: Error in eval(expr, envir, enclos) : object "qvartemp" not found but this object exist: [1] "cont" "i" "levelsord" "mma" "qvar" "qvarmma" [7] "qvartemp" "test"
2010 Sep 16
1
Help for an absolutely r-noob
Hello together, I am an absolute noob in R and therefore I need help urgently. I have received a script from my tutor with plot functions in it. However, I can' manage to adapt these plots. The hole script is as follows: setwd("E:/") ##### (1) Read data ### dat <- read.table("Komfort_Tatsaechliche_ID_Versuchsreihe_1.txt", header=TRUE, sep="\t",
2017 Jun 21
0
Help/ Mathematics
Hi Ahmed, Your problem appears trivial as you have already specified the form of the calculation. Learn how to "extract" specified elements from a data structure: # first value sum(dataset1$NPP[dataset1$date >= date1 & dataset1$date <= date2]) # second value dataset2$biomass[dataset2$date == date2] - dataset2$biomass[dataset2$date == date1] # third value
2003 Apr 08
2
Basic LME
Hello R Users, I am investigating the basic use of the LME function, using the following example; Response is Weight, covariate is Age, random factor is Genotype model.lme <- lme (Weight~Age, random=~ 1|Genotype) After summary(model.lme), I find that the estimate of Age is 0.098 with p=0.758. I am comparing the above model with the AOV function; model.aov <- aov (Weight~Age + Genotype)
2011 Apr 20
3
succession time series graph
Dear gracious R community, I would like to produce charts of phytoplankton biomass changes through time. Each species has a line, and the biomass varies in mirror form along the line for each species along the X time axis. Here is an example of what I'd like to do: http://www.er.uqam.ca/nobel/r30240/Succession.jpg Any suggestions? Thanks David Bird UQAM, Montreal
2009 Jul 23
1
simple lme question
Hi everyone, I am trying to analyse my data from a small plant experiment (for a meeting tomorrow afternoon) and am a beginner to R so I apologise if this is a very basic question. I carried out a plant experiment examining plant interactions between two species (A and B) under different watering treatments. I had: - 7 watering treatments (7 different watering frequencies labelled 1-7) - 3
2004 Jan 05
3
Heeeeeelp! Estimatet Marginal Means of ANOVA needed!
Hello! I urgently need to know if it is possible (and if so, how to do) to get the "Estimatet marginal means" from an ANOVA. Or explained more coplicated: It's about plants sewn in 2 densities & 2 patterns. The Variable is biomass and I also use a Covariate. There are highly significant differences between density & pattern but I don't know which of the 2 densities
2017 Jun 21
4
Help/ Mathematics
Hi R users, I need your help to write a code in r that does the following calculation from three different datasets; ac = 1/sum (NPP from date 1 to date 2, dataset=1) * (biomass at date 2 -biomass at date 1, dataset = 2) + (littfall at date 2, dataset=3). all the dates are in yr-month-day format. Which library or function Should I use to tell R do these calculations of these variables at
2013 Mar 26
2
Problem with nested for-loop
Hello, I'm working on a problem using nested for-loops and I don't know if it's a problem with the order of the loops or something within the loop so any help with the problem would be appreciated. To briefly set up the problem. I have 259 trees (from 11 different species, of unequal count for each species) of which I am trying to predict biomass. For each tree species I have 10000
2011 Aug 24
1
R (&stats) newcomer.... help!
Hi all, I hope that i've posted this in the correct place. if not, please accept my apologies (where should this go?) I have carried out experimental removal of bivalves at 2 intertidal shores. Bivalves were removed by raking of surface sediments. I wish compare the biomass values of for a total of 8 species between the 2 shores My 3 treatments are: Undisturbed Controls (Cont), Procedural
2011 Sep 27
1
ANOVA define as factor or not
Hi all This is probably a simple problem but somehow I am having much trouble with finding a solution, so I seek your help! I have a data-set with continuous response variables. The explanatory variably is 4xpH treatments (so 8.08, 7.94, 7.81 and 7.71) so also continuous and not technically factorial. However I have decided to do Anova's (as well as regression) to explore the effect of
2007 May 24
4
Function to Sort and test AIC for mixed model lme?
Hi List I'm running a series of mixed models using lme, and I wonder if there is a way to sort them by AIC prior to testing using anova (lme1,lme2,lme3,....lme7) other than by hand. My current output looks like this. anova (lme.T97NULL.ml,lme.T97FULL.ml,lme.T97NOINT.ml,lme.T972way.ml,lme.T97fc. ml, lme.T97ns.ml, lme.T97min.ml) Model df AIC BIC logLik
2017 Jun 30
3
Predict
Sorry for the confusion, here is the edited question. The data= Stand_Height (attached) is recorded from 12/1/2009 to 12/31/2015 (25 observations) and the other dataset (leafbiom) is recorded from 10/7/2009 to 12/29/2016 (daily observations). I want to use the 25 observations of stand height to predict the daily stand height from 10/7/2009 to 12/29/2016. The daily stand height will be multiplied