Displaying 20 results from an estimated 3000 matches similar to: "help with syntax of random formula"
2012 Nov 12
2
Using "apply" instead of "for" loop / multithreading
Hello ,
I'm new to R and don't really understand how to use the function "apply"
instead of a "for loop", particularly for a function with multiple entries.
I have a big data file and would like to apply a function in multi thread to
accelerate the processus.
I have a data frame containing values of* CO2 in ppm (resp[i,6])* that I
want to convert in umol of CO2
2012 Mar 21
1
nlme error on dimensions in multiplication
Hello R users,
When trying to fit a nonlinear mixed model to a respiration time series,
I get the following error message:
Error in recalc.varFunc(object[[i]], conLin) :
dims [product 30] do not match the length of object [34]
In addition: Warning message:
In conLin$Xy * varWeights(object) :
longer object length is not a multiple of shorter object length
Below is an example that generates
2007 Mar 07
5
how to "apply" functions to unbalanced data in long format by factors......cant get "by" or "aggregate" to work
Hello R users,
Problem.......I do not understand how to use "aggregate","by", or the
appropriate "apply" to perform a function on data with more than one
factor on unbalanced data...
I have a data frame in the long format that does not contain balanced
data. The ID is a unique identifier corresponding to the experimental
unit that will later be examined by ANOVA,
2008 Jul 20
2
problem with read.table
Hi,
Although I set check.names to FALSE in read.table, the duplicate names get modified. What should be done in this case?
the text file to be read by read.table
AM2 AM2 AM2 FAL
2 3 4 5
1 -1 -3 -2
t = read.table ("my_file", check.names = FALSE, header = T)
> t
AM2 AM2.1 AM2.2 FAL
1998 Dec 29
0
Sharing TAPES ?
Hello!
Is it possible to make a tape attached to unix host visible
to windows PCs via Misrosoft's protocol?
Now our users should telnet to the unix station and use smbtar.
They want to use backup utilities from Windows. Is it possible?
Sincerely,
Ilya Ovchinnikov -------------------------------------
Internet Service and Information
ILO2-RIPE
2006 May 24
1
general Gauss-Newton or support for NSUR: contemporaneously correlated non-linear models
Dear r-Help readers,
1) Is there support for NSUR in some R package yet?
2) Is there a general function of applying the Gauss-Newton or Marquard
method, in which the function of calculating the partial derivatives can
be specified by the user?
Contemporaneously correlated non-linear models (NSUR) is a method to fit
a system of non-linear equations.
I want to use to fit several non-linear
2004 Apr 19
0
SE for combined data
Dear all
I have just had the question from a colleague. I know that it is not directly related to R (I will probably use R to do the analysis), but I hope someone can give us some insight:
Thanks,
AJ Smit
I sampled populations of a seaweed in the intertidal in order to estimate
the standing biomass of that seaweed at that site.
Due to clumped distribution patterns, I chose a stratified
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)
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
2017 Jul 06
0
Bayes Factor
Hello R Community,
Subject: Bayes Factor
A Bayesian ANOVA of the form:
competitionBayesOut <- anovaBF(biomass ~ clipping, data = competition)
Returns the following Error message:
Error in (function (classes, fdef, mtable) :
unable to find an inherited method for function ?compare? for
signature ?"BFlinearModel", "missing", "tbl_df"?
My guess the problem is in
2012 Sep 14
1
linear mixed-effects models with two random variables?
Dear R users,
Does anyone knows how to run a glmm with one fixed factor and 2 random
numeric variables (indices)? Is there any way to force in the model a
separate interaction of those random variables with the fixed one?
I hope you can help me.
#eg.
Reserve <- rep(c("In","Out"), 100)
fReserve <- factor(Reserve)
DivBoulders <- rep
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
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,
2010 Sep 16
0
problems trying to reproduce structural equation model using the sem package
Hello,
I've been unsuccessfully trying to reproduce a sem from Grace et al.
(2010) published in Ecological Monographs:
http://www.esajournals.org/doi/pdf/10.1890/09-0464.1
The model in question is presented in Figure 8, page 81. The errors
that I've been getting are:
1. Using a correlation matrix:
res.grace <- sem(grace.model, S = grace, N = 190)
Warning message:
In sem.default(ram
2009 Feb 06
0
party package conditional variable importance
Hello,
I'm trying to use the party package function varimp() to get
conditional variable importance measures, as I'm aware that some of my
variables are correlated. However I keep getting error messages (such
as the example below). I get similar errors with three separate
datasets that I'm using. At a guess it might be something to do with
the very large number of variables (e.g.
2010 Dec 29
2
HELP for repeated measure ANCOVA with varying covariate
Dear All,
I am a researcher doing research in plant growth and I have a
statistical problem that seems to not be able to handle. Recently, I
conducted an experiment about plant growing in three different
nutrient-level sediments. I harvested these every three week (three
harvests in all). Some growth traits of these plants were recorded (e.g.
total biomass, leaf biomass and stem biomass). In
2010 Apr 25
1
Manipulating text files
Dear R Community,
I am trying to optimize a water quality model that I am using. Based on conversations with others more familiar with what I am doing I plan to implement DEOptim to do this. The water quality model is interfaced through a GUI. I have the input file necessary to alter parameters and run the model as a text file.
To do the optimization I have figured out the general procedure
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
2010 Mar 02
0
plotting fitted lme values as a smooth line
I am trying to plot fitted lme values as a smooth line of a graph
showing the exponential relationship between temperature and soil
respiration.
In the plot, the x-axis has temperature, and the y-axis has soil
respiration. When I try to add a line showing temperature versus the
fitted values, it is jagged and not smooth.
Here is the code I used:
lme.1<-lme(fixed=LnFlux~Temp,