I am calculating in R an ANOVA with repeated measures in 2x2 mixed design. For this I use one of the following inputs in R:
(1)
res.aov <- anova_test(data = datac, dv = Stress, wid = REF,between = Gruppe, within = time )
get_anova_table(res.aov)
(2)
aov <- datac %>%
anova_test(dv = Stress, wid = REF, between = Gruppe, within = time, type = 3)
aov
Both lead to the same results. Now I want to add a covariate from the 1st measurement time point. So far I could not find a suitable R input for the ANCOVA for this repeated measures design.
Does anyone of you perhaps have an idea?
Many greetings
ANOVA <- aov(Stress~time+covariate, data = data)
summary(ANOVA)
For a simple ANCOVA, the R input of an ANOVA with the addition of the covariate applies. Unfortunately, I have no idea how this works in the repeated measures design.
Related
Problem: I'm trying to perform a Computing a multinominal logistic multilevel regression. I try to follow this approach:
multinomial logistic multilevel models in R
Details: Therefor I computed six separate models with glmr from the lm4 package from R.
I would like to investigate the influence that meaning in life has on people's everyday lives.
As dependent variables I have pleasant days, meaningful days, pleasant-meaningful days and meaningful-unpleasant days.
I have always made pairwise comparisons as described in the link and have always excluded the other cases.
Question I: Is my approach correct?
#Model-1
#comparision_1:meaningful-pleasant days vs. pleasant days
Model.1 <- glmer(comparision_1~ 1+ (1|subject_id), data = data, family = binomial(), na.action = na.omit)
summary(eelModel.1)
#comparision_2: meaningfulday-pleasant days vs. meaningfuldays,
eelModel.2 <- glmer(comparision_2~ 1+ (1|subject_id), data = data, family = binomial(), na.action = na.omit)
... and so on.
#Model-2
#comparision_1:meaningful-pleasant days vs. pleasant days
Mode2.1 <- glmer(comparision_1~ meaning_in_life+ (1|subject_id), data = data, family = binomial(), na.action = na.omit)
summary(eelModel.1)
#comparision_2: meaningfulday-pleasant days vs. meaningfuldays,
Mode2.2 <- glmer(comparision_2~ meaning_in_life+ (1|subject_id), data = data, family = binomial(), na.action = na.omit)
... and so on.
Question II: Are the estimates from the Output the log-odds? Or do I have to compute them?
Thanks for your help,
Christoph
I am using R Markdown to create an html file for regression results tables, which are produced by stargazer and lfe in a code chunk.
library(lfe); library(stargazer)
data <- data.frame(x = 1:10, y = rnorm(10), z = rnorm(10))
result <- stargazer(felm(y ~ x + z, data = data), type = 'html')
I create a html file win an inline code r result after the chunk above. However, a bunch of commas appear at the top of the table.
When I check the html code, I see almost every </tr> is followed by a comma.
How can I delete these commas?
Maybe not what you are looking for exactly but I am a huge fan of modelsummary. I knit to HTML to see how it looks and then usually knit to pdf. The modelsummary equivalent would look something like this
library(lfe)
library(modelsummary)
data = data.frame(x = 1:10, y = rnorm(10), z = rnorm(10))
results = felm(y ~ x + z, data = data)
modelsummary(results)
There are a lot of ways to customize it through kableExtra and other packages. The documentation is really good. Here is kind of a silly example
library(kableExtra)
modelsummary(results,
coef_map = c("x" = "Cool Treatment",
"z" = "Confounder",
"(Intercept)" = "(Intercept)")) %>%
row_spec(1, background = "#F5ABEA")
I am using a data set called sleep (found here: https://drive.google.com/file/d/15ZnsWtzbPpUBQN9qr-KZCnyX-0CYJHL5/view) to run a three way within subject ANOVA comparing Performance based on Stimulation, Deprivation, and Time. I have successfully done this before using anova_test from rstatix. I want to look at the sphericity output but it doesn't appear in the output. I have got it to come up with other three way within subject datasets, so I'm not sure why this is happening. Here is my code:
anova_test(data = sleep, dv = Performance, wid = Subject, within = c(Stimulation, Deprivation, Time))
I also tried to save it to an object and use get_anova_table, but that didn't look any different.
sleep_aov <- anova_test(data = sleep, dv = Performance, wid = Subject, within = c(Stimulation, Deprivation, Time))
get_anova_table(sleep_aov, correction = "GG")
This is an ideal dataset I pulled from the internet, so I'm starting to think the data had a W of 1 (perfect sphericity) and so rstatix is skipping this output. Is this something anova_test does?
Here also is my code using a dataset that does return Mauchly's:
weight_loss_long <- pivot_longer(data = weightloss, cols = c(t1, t2, t3), names_to = "time", values_to = "loss")
weight_loss_long$time <- factor(weight_loss_long$time)
anova_test(data = weight_loss_long, dv = loss, wid = id, within = c(diet, exercises, time))
Not an expert at all, but it might be because your factors have only two levels.
From anova_summary() help:
"Value
return an object of class anova_test a data frame containing the ANOVA table for independent measures ANOVA. However, for repeated/mixed measures ANOVA, it is a list containing the following components are returned:
ANOVA: a data frame containing ANOVA results
Mauchly's Test for Sphericity: If any within-Ss variables with more than 2 levels are present, a data frame containing the results of Mauchly's test for Sphericity. Only reported for effects that have more than 2 levels because sphericity necessarily holds for effects with only 2 levels.
Sphericity Corrections: If any within-Ss variables are present, a data frame containing the Greenhouse-Geisser and Huynh-Feldt epsilon values, and corresponding corrected p-values. "
After updating Openturns from 1.15 to 1.16rc1 I have the following issue with building the meta-model of the field function:
to reduce the computational burden:
ot.ResourceMap.SetAsUnsignedInteger("FittingTest-KolmogorovSamplingSize", 1)
algo = ot.FunctionalChaosAlgorithm(sample_X, outputSampleChaos)
algo.run()
metaModel = ot.PointToFieldConnection(postProcessing, algo.getResult().getMetaModel())
The "FittingTest-KolmogorovSamplingSize" was removed from OpenTurns 1.16rc1 and when I try to replace the fitting test with:
ot.ResourceMap.SetAsUnsignedInteger("FittingTest-LillieforsMaximumSamplingSize", 10)
Or with
ot.ResourceMap.SetAsUnsignedInteger("FittingTest-LillieforsMinimumSamplingSize", 1)
The code is freezing. Is there any solution for this?
The proposed solution is simply to use another distribution to model your data. You could have used any other multivariate continuous distribution of proper dimension. IMO it is not a valid answer as the distribution has no link to your data.
After inspection, it appears that the problem has nothing to do with Lilliefors's test. In OT 1.15 we were using this test (under the wrong name of Kolmogorov) to select automatically a distribution suited to the input sample, but we switched to a more sophisticated selection algorithm (see MetaModelAlgorithm::BuildDistribution). It is based on a first pass using the raw Kolomgorov test (thus ignoring the fact that parameters have been estimated) then an information-based criterion is used to select the most relevant model (AIC, AICC, BIC depending on the value of the "MetaModelAlgorithm-ModelSelectionCriterion" key in ResourceMap. The problem is caused by the TrapezoidalFactory class during the Kolmogorov phase. I will provide a fix ASAP in OpenTURNS master. In the mean time, I have adapted the proposed solution to something more adapted to your data:
degree = 6
dimension_xi_X = 3
dimension_xi_Y = 450
enumerateFunction = ot.HyperbolicAnisotropicEnumerateFunction(dimension_xi_X, 0.8)
basis = ot.OrthogonalProductPolynomialFactory(
[ot.StandardDistributionPolynomialFactory(ot.HistogramFactory().build(sample_X[:,i])) for i in range(dimension_xi_X)], enumerateFunction)
basisSize = enumerateFunction.getStrataCumulatedCardinal(degree)
#basis = ot.OrthogonalProductPolynomialFactory(
# [ot.HermiteFactory()] * dimension_xi_X, enumerateFunction)
#basisSize = 450#enumerateFunction.getStrataCumulatedCardinal(degree)
adaptive = ot.FixedStrategy(basis, basisSize)
projection = ot.LeastSquaresStrategy(
ot.LeastSquaresMetaModelSelectionFactory(ot.LARS(), ot.CorrectedLeaveOneOut()))
ot.ResourceMap.SetAsScalar("LeastSquaresMetaModelSelection-ErrorThreshold", 1.0e-7)
algo_chaos = ot.FunctionalChaosAlgorithm(sample_X,
outputSampleChaos,basis.getMeasure(), adaptive, projection)
algo_chaos.run()
result_chaos = algo_chaos.getResult()
meta_model = result_chaos.getMetaModel()
metaModel = ot.PointToFieldConnection(postProcessing,
algo_chaos.getResult().getMetaModel())
I also implemented a quick and dirty estimator of the L2-error:
# Meta_model validation
iMax = 5
# Input values
sample_X_validation = ot.Sample(np.array(month_1_parameters_MSE.iloc[:iMax,0:3]))
print("sample size=", sample_X_validation.getSize())
# sample_X = ot.Sample(month_1_parameters_MSE[['Rseries','Rsh','Isc']])
# output values
#month_1_simulated.iloc[0:1].transpose()
Field = ot.Field(mesh,np.array(month_1_simulated.iloc[0:1]).transpose())
sample_Y_validation = ot.ProcessSample(1,Field)
for k in range(1,iMax):
sample_Y_validation.add( np.array(month_1_simulated.iloc[k:k+1]).transpose() )
# In[18]:
graph = sample_Y_validation.drawMarginal(0)
graph.setColors(['red'])
drawables = graph.getDrawables()
graph2 = metaModel(sample_X_validation).drawMarginal(0)
graph2.setColors(['blue'])
drawables = graph2.getDrawables()
graph.add(graph2)
graph.setTitle('Model/Metamodel Validation')
graph.setXTitle(r'$t$')
graph.setYTitle(r'$z$')
drawables = graph.getDrawables()
L2_error = 0.0
for i in range(iMax):
L2_error = (drawables[i].getData()[:,1]-drawables[iMax+i].getData()[:,1]).computeRawMoment(2)[0]
print("L2_error=", L2_error)
You get an error of 79.488 with the previous answer and 1.3994 with the new proposal. Here is a graphical comparison.
Comparison between test data & previous answer
Comparison between test data & new proposal
The solution is to use:
degree = 1
dimension_xi_X = 3
dimension_xi_Y = 450
enumerateFunction = ot.LinearEnumerateFunction(dimension_xi_X)
basis = ot.OrthogonalProductPolynomialFactory(
[ot.HermiteFactory()] * dimension_xi_X, enumerateFunction)
basisSize =450 #enumerateFunction.getStrataCumulatedCardinal(degree)
adaptive = ot.FixedStrategy(basis, basisSize)
projection = ot.LeastSquaresStrategy(
ot.LeastSquaresMetaModelSelectionFactory(ot.LARS(), ot.CorrectedLeaveOneOut()))
ot.ResourceMap.SetAsScalar("LeastSquaresMetaModelSelection-ErrorThreshold", 1.0e-7)
algo_chaos = ot.FunctionalChaosAlgorithm(sample_X,
outputSampleChaos,basis.getMeasure(), adaptive, projection)
algo_chaos.run()
result_chaos = algo_chaos.getResult()
meta_model = result_chaos.getMetaModel()
metaModel1 = ot.PointToFieldConnection(postProcessing,
algo_chaos.getResult().getMetaModel())
I have the following mixed effects model:
p1 <- lmer(log(price) ~ year*loca + (1|author), data = df)
'year' is continuous
'loca' is categorical variable with 2 levels
I am trying to plot the significant interaction from this model.
The following code (using the visreg package) plots the lines from each of the two 'loca' but it does not produce a 95% confidence band:
visreg(p1, "year", by = "loca", overlay = T,
line=list(lty = 1, col = c("grey", "black")), points=list(cex=1, pch=19,
col = c("grey", "black")), type="conditional", axes = T)
Then, I tried the following code which allows me to plot the lines, but with no data points on top and no CIs:
visreg(p1, "year", by = "loca", overlay = T,
line=list(lty = 1, col = c("grey60", "black")), points=list(cex=1,
pch=19, col = c("grey", "black")),
type="conditional", trans = exp, fill.par = list(col = c("grey80",
"grey70")))
I get CI bands when I use type = 'contrast' rather than 'conditional'. However, this doesn't work when I try to backtransform the price as above using trans = exp.
Overall I need to be able to plot the interaction with the following attributes:
Confidence bands
backtransformed points
predicted line (one for each level of 'loca')
More than happy to try other methods....but I can't seem to find any that work so far.
Help much appreciated!
one possibility is with the use of the effects package:
library(effects)
eff.p1 <- effect("year*loca", p1, KR=T)
then you could either directly plot it with what the package provides and customize it from there:
plot(eff.p1)
or take what effect produces and plot it with ggplot in a nicer plot:
eff.p1 <- as.data.frame(eff.p1)
ggplot(eff.p1, aes(year, linetype=factor(loca),
color = factor(loca))) +
geom_line(aes(y = fit, group=factor(loca)), size=1.2) +
geom_line(aes(y = lower,
group=factor(loca)), linetype =3) +
geom_line(aes(y = upper,
group=factor(loca)), linetype =3) +
xlab("year") +
ylab("Marginal Effects on Log Price") +
scale_colour_discrete("") +
scale_linetype_discrete("") +
labs(color='loca') + theme_minimal()
I can't really try the code without the data, but I think it should work.
This should do the trick:
install.packages(sjPlot)
library(sjPlot)
plot_model(p1, type = "int", terms = c(year,loca), ci.lvl = 0.95)
Although it comes out with some warnings about labels, testing on my data, it does the back transformation automatically and seems to work fine. Customising should be easy, because I believe sjPlot uses ggplot.
EDIT: #Daniel points out that alternative options which allow more customization would be plot_model(type = "pred", ...) or plot_model(type = "eff", ...)