Displaying 20 results from an estimated 10000 matches similar to: "acts_as_list sort by multiple items"
2005 Mar 22
1
List of tables rather than an extra dimension in the table or (l)apply(xtabs)
I'm not sure how to best explain what I am after but here goes. I have a data frame with 2 geographical factors. One is the major region the other is the component regions.
I am trying to process all the regions at the same time without using "for". So I need (think, I do) a list of matrices each structured according to the number of subregions within each region.
So is there a
2008 Feb 26
0
NLS -- multiplicative errors and group comparison
Hello,
I am attempting to fit a non-linear model (Von Bertalanffy growth model)
to fish length-at-age data with the purpose of determining if any of the
three parameters differ between male and female fish. I believe that I
can successfully accomplish this goal assuming an additive error
structure (illustrated in section 1 below). My trouble begins when I
attempt this analysis using a model
2010 Mar 11
2
as.integer and indexes error
Hello All,
I would like to report the following bug or maybe you can explain if I am
wrong.
I am sampling from two different populations with weights. The two
populations have the same age groups and I want to distinguish where I am
sampling from. That is why I am using a matrix such as:
matrix
age.group Male Females Weight.Males Weight.Females
1 1.1
2012 May 04
1
Correct Interpretation of survreg() coeffs
Am I correct in assuming that the output below essentially translates to
"Males have a mean time that is significantly lower than Females"? Is this
the correct way to interpret the fact that the coefficient is negative?
Assume the variale sex is treated as a factor with Female =0 and Male=1.
survmodel<-survreg(survobj~sex,data=data1, dist="weibull")
2008 Aug 24
1
Plotting 3 way Anova
Hi
I'd really like to get a bar plot showing the means of my anova data. I have looked everywhere and can only seem to find instructions for 2 way anova's.
I basically want to look at the mean condition of my subjects spilt by age, sex and year (as a factor rather than a continuous variable, hence Anova and not Ancova). and want to show it firstly as a bar graph with standard error. I
2008 Feb 12
1
Finding LD50 from an interaction Generalised Linear model
Hi,
I have recently been attempting to find the LD50 from two predicted fits
(For male and females) in a Generalised linear model which models the effect
of both sex + logdose (and sex*logdose interaction) on proportion survival
(formula = y ~ ldose * sex, family = "binomial", data = dat (y is the
survival data)). I can obtain the LD50 for females using the dose.p()
command in the MASS
2008 Mar 03
1
Barplot with grouping x axis and count data
Hello,
I am trying to make a barplot with nested count data which is build like
this: first there are several birds (n)laying 3 clutches composed of 2 eggs
half of the second and third clutch received treatment and this treatment
was tested to influence sex of offspring. I want a barplot showing counts
for male and female for every egg of every clutch. can someone tell me what
to do? I drew a
2011 Dec 30
2
Joint modelling of survival data
Assume that we collect below data : -
subjects = 20 males + 20 females, every single individual is independence,
and difference
events = 1, 2, 3... n
covariates = 4 blood types A, B, AB, O
http://r.789695.n4.nabble.com/file/n4245397/CodeCogsEqn.jpeg
?m = hazards rates for male
?n = hazards rates for female
Wm = Wn x ?, frailty for males, where ? is the edge ratio of male compare to
female
Wn =
2013 Nov 04
0
Fwd: recodificar variables
Hola Alexander.
Para filtrar y obtener el subconjunto que necesitas, puedes hacerlo de la siguiente (una de ellas) manera:
> Female <- subset(MathAchieve, subset=Sex=="Female")
Crear una nueva variable recodificando "Sex" puedes hacerlo así:
> Sex_recode <- Recode(MathAchieve$Sex, '"Female"=1; "Male"=0; ;', as.factor.result=TRUE)
>
2009 Aug 31
1
GLM contrasting question
I have run a glm with a final formula of : (dependent variable = parasite
load, main effects are sex, month, length and weight, with sex:month and
length:weight first order interactions).
I am using the summary(mod) command to give me the contrasts, which I
believe use the contr.treatment command. I do not have a treatment group as
such as I am comparing data from a wild system so I use the
2008 Sep 06
2
Hopefully an easy error bar question
Hi im trying to add error bars to my barplots, there very basic, i have a few grapghs where the y variable is different but on all the X variable is Age (Adult and Juvenile) however this is split into two levels so i have males and females, so my graph basically has four bars on it.
I know how to add eror bars for instance when there is only one level eg lookng at the diffrence between male and
2008 Feb 06
1
Nested ANOVA models in R
Hi,
I'm trying to work through a Nested ANOVA for the following scenario:
20 males were used to fertilize eggs of 4 females per male, so that
female is nested within male (80 females used total). Spine length
was measured on 11 offspring per family, resulting in 880
measurements on 80 families.
I used the following two commands:
summary(aov(Spinelength ~ Male*Female))
and
2010 Apr 01
0
Analyzing binary data on an absolute scale and determining conditions when risks become equal between groups
Suppose I have a binary outcome (disease/no disease and all subjects had the same period of exposure) and 2 or 3 (categorical) predictors.
I can obviously build a logistic regression model which describes the data, possibly including interaction terms, on a relative scale:
model<-glm(disease~sex*race*prematurity,family=binomial)
1) Is there any way to extract information on the absolute
2011 Mar 15
1
binary exogenous variable in path analysis in sem or lavaan
Hello all
I'm trying to run some path analysis in either sem or lavaan (preferably lavaan because I find its interface easier to use). Most of my variables are continuously distributed and fairly well-behaved but I have a single exogenous variable (sex) which is not continuously distributed. Preliminary model fitting suggests that there aren't any sex by (anything else) interactions. The
2011 May 21
0
Problem with ANOVA repeated measures: "Error() model is singular"
Hello everybody,
I need an help because I don´t know if the command for the ANOVA analysis I am
performing in R is correct. Indeed using the function aov I get the following error:"In aov (......) Error() model is singular"
The structure of my table is the following: subject, stimulus, condition, sex, response
Example:
subject stimulus condition sex response
2012 Apr 26
2
Subsetting dataframe with missing values
Dear R-community,
I am using R (V 2.14.1) on Windows 7. I have a dataset which consists of 19
variables for 91 individuals or rows. Two of my variables are Age
(adult/chick, with no NA values) and Sex (0 for females/1 for females, with
quite a few NA values). The sex of many adult birds is unknown (entered as
NA in dataframe). At some point of my analyses, I happen to need to need to
work with
2004 Aug 05
1
cross random effects (more information abuot the data)
Dear friends,
I have asked last few days about cross-random effects
using PQL, but I have not receive any answer because
might my question was not clear.
My question was about analysing the salamander mating
data using PQL. This data contain cross-random effects
for (male) and for (female). By opining MASS and lme
library. I wrote this code
sala.glmm <- glmmPQL(fixed=y~WSf*WSM,
2005 Dec 24
2
grouping data
Hello R-users/experts,
I am new to R-
I have a simple question:
Let say I have a data set as follows
temp:[file attached]
the data structure is a follows:
sex age
female 28
female 53
female 53
female 36
male 42
male 29
male 43
male 36
male 41
Here we are grouping all male value into male and all female value in to
female
working out main effect variance when different parameterization is used and interaction term exists
2010 Jul 13
0
working out main effect variance when different parameterization is used and interaction term exists
Dear all,
Apologies if this question is bit theoretical and for the longish email.
I am meta-analyzing the coefficients and standard errors from multiple
studies where the raw data is not available.
Each study analyst runs a model that includes an interaction term for,
say, between sex and smoking and age.
Here is an illustrative example example for one study:
set.seed(1066)
status
2012 Oct 05
1
Error in lmer: asMethod(object) : matrix is not symmetric [1, 2]
Dear R Users,
I am having trouble with lmer. I am looking at recombinant versus non
recombinant individuals. In the response variable recombinant
individuals are coded as 1's and non-recombinant as 0's. I built a model
with 2 fixed factors and 1 random effect. Sex (males/females) is the
first fixed effect and sexual genotype (XY, YY, WX and WY) the second
one. Sexual Genotype is