means , CIs from lmer, glmer
On 27 February 2018 at 15:27, Kornbrot, Diana <d.e.kornbrot at herts.ac.uk> wrote:
Thanks Am also replying to list, so excuse duplication used install packages followed by library though that was happening on 1st attempt - but sadly no On 27 Feb 2018, at 12:53, Rune Haubo <rune.haubo at gmail.com> wrote: Well, you could also just do a linear mixed model on the logit-transformed proportions, which would make the Satterthwaite F-tests via lmerTest available to you. This can be OK if all the proportions have (approximately) the same denominator but usually *ALWAYS*
No, not always, but usually. In 'regular' cases (designed experiment with the same denominator) the anova F-test is superior to the asymptotic chi-square tests in the 'right' model.
is better to fit the 'correct' binomial mixed model with glmer - even when all the proportions have the same denominator. Using glmer leaves you with likelihood ratio tests which are matched against the chi-square distribution - use anova(model2, model1) to obtain these likelihood ratio tests. It would be helpful if glmer did not [rpobably incorrectly] label chi-square tests as ?F?
I don't think it does:
library(lme4)
gm1 <- glmer(cbind(incidence, size - incidence) ~ period + (1 | herd),
cbpp, binomial)
anova(gm1, gm2 <- update(gm1a, ~.-period))
Data: cbpp
Models:
gm2 <- update(gm1a, ~. - period): cbind(incidence, size - incidence) ~ (1 |
herd)
gm1: cbind(incidence, size - incidence) ~ period + (1 | herd)
Df AIC BIC logLik deviance Chisq
Chi Df
gm2 <- update(gm1a, ~. - period) 2 213.66 217.71 -104.832 209.66
gm1 5 194.05 204.18 -92.027 184.05 25.61
3
Pr(>Chisq)
gm2 <- update(gm1a, ~. - period)
gm1 1.151e-05 ***
---
Signif. codes: 0 ?***? 0.001 ?**? 0.01 ?*? 0.05 ?.? 0.1 ? ? 1
[actually, and to my surprise, anova(gm1) prints something that looks like
an anova table with a column labeled 'F', but I don't know what that means
(if it has a meaning). Wiser heads than mine will have to chip in here...]
But this is a generalised linear model and was hoping get a mean and sd for the random subject (Participant) effect
Just printing the object (e.g. gm1) does give you the standard deviations for the random effects. The mean is zero per definition, but I suspect that this is not what you are really asking for?
Also really do want an F comparing the predictor effects with appropriate error effects
I personally think that is an odd thing to ask for and I have no clue how it is reasonably defined. I suspect you may have to use SPSS. I don't really know what SPSS is doing but if it is doing a PQL-kind of thing that would explain why you are led in the direction of F-tests (but note that PQL is much inferior to the Laplace and AGQ methods in glmer). Best Rune
It seems the in spite of R supposedly being more sophisticated than
standard packages like SPSS, it has fewer options on the crucial issue of
specifying error variance
And by the way: you probably want to install the emmeans package via
'install.packages("emmeans")' in R - not via gitHub using devtools.
See https://github.com/runehaubo/lmerTest under 'Installation' for the
advice we give on installing lmerTest. Short version is to install
using install.packages() before thinking about installing from github.
good advice
results form SPSS and R are very different
R glmer MIXED
Rab Between emmean SE df asymp.LCL asymp.UCL Rab Between Mean SE lcl ucl
1 1 -.316 .170 Inf -.650 .018 1 1 -.267 .148 -.562 .027
2 1 -.820 .172 Inf -1.158 -.482 2 1 -.688 .169 -1.023 -.352
3 1 -1.838 .183 Inf -2.196 -1.480 3 1 -1.550 .188 -1.924 -1.176
4 1 -2.558 .198 Inf -2.946 -2.170 4 1 -2.168 .230 -2.624 -1.712
1 2 .357 .165 Inf .034 .681 1 2 .297 .144 .011 .583
2 2 -.895 .167 Inf -1.223 -.567 2 2 -.745 .165 -1.073 -.417
3 2 -2.607 .192 Inf -2.984 -2.230 3 2 -2.238 .235 -2.705 -1.772
4 2 -2.891 .201 Inf -3.285 -2.497 4 2 -2.498 .255 -3.005 -1.992
Df SS MS F Source F df1 df2 Sig.
Rab 3 870.17 290.06 290.06 Rab 66.76 3 94 .000000
Between 1 .12 .12 .12 Between .38 1 93 .539643
Rab:Between 3 63.20 21.07 21.07 Rab*Between 5.31 3 94 .001998
Corrected 30.64 7 101 .000000
best
Diana
Best regards,
Rune Haubo B. Christensen, PhD, MSc.
Director, Owner
Christensen Statistics
Bringetoften 7
<https://maps.google.com/?q=Bringetoften+7&entry=gmail&source=g>
3500 V?rl?se - Denmark
+45 3026 4554 <+45%2030%2026%2045%2054>
Rune at ChristensenStatistics.dk
www.ChristensenStatistics.dk
On 27 February 2018 at 12:32, Kornbrot, Diana <d.e.kornbrot at herts.ac.uk>
wrote:
thanks
do you have any suggestions for glmer?
SPSS seems happy to do Sattherwaite, which seems to be alogical approach
for any model that is effectively doing a multivariate ANOVA on the logit
transformed proportion
best
Diana
On 27 Feb 2018, at 10:22, Rune Haubo <rune.haubo at gmail.com> wrote:
Just a small note that lmerTest (and the Satterthwaite method for
degrees of freedom) is only meaningful for _linear_ mixed models - not
for the generalized variants such as the one considered here for
proportions.
Best,
Rune
On 27 February 2018 at 02:02, Ben Bolker <bbolker at gmail.com> wrote:
Hi Diana,
A reproducible example is always helpful/increases your chances of
getting a useful answer ...
It might help if you included the SPSS output (or posted it somewhere
-- note that this list doesn't take HTML-formatted messages nor most
attachments), as many of us don't have access to it.
Look into the (very well-documented) emmeans package:
https://CRAN.R-project.org/package=emmeans
and the lmerTest package (for Satterthwaite df approximations)
On Mon, Feb 26, 2018 at 12:11 PM, Kornbrot, Diana
<d.e.kornbrot at herts.ac.uk> wrote:
I am keen to promote the use of generalised mixed models for the analysis
of
proportions to psychologists
Have straight fowl code in SPSS [costly] and would like to supply
equivalent
R Code without ?tears?
Design is a follows raw frequencies are: FreqPos for ?success? and FreqNeg
for ?failure?
Predictors are Rab with 4 levels, repeated over participants and Between
with 2 separate groups of participants
Model is binomial with logit link
Require following output to correspond to SPSS output from code below
Descriptive: Means, se and 95% CIs by Rab, by Between and by Rab*Between
Inferential: fo Rab, Between and Rab*Between: F value, MSE, numerator df,
denominator df [this enables p-values]
Have tried
logit1 <- glmer(cbind(FreqPos,FreqNeg) ~ Rab + Between + Rab*Between + (1|
Participant), family=binomial(link="logit"))
gives F and MSE no denominator df or MSE. Different results to SPSS
nb F=MSE - that can?t be right F is supposed to be ratio of chi-squares
summary (logit1)
gives coefficients and SEs. Different results to SPSS
also tried predicted and fitted but still no means
have spent days searching internet for examples - but none of them seem to
show how to get the output I need
All help greatly appreciated
____
Spss syntax
*Generalized Linear Mixed Models.
GENLINMIXED
/DATA_STRUCTURE SUBJECTS=Participant REPEATED_MEASURES=Rab
COVARIANCE_TYPE=UNSTRUCTURED
/FIELDS TARGET=FreqPos TRIALS=FIELD(Nmax) OFFSET=NONE
/TARGET_OPTIONS DISTRIBUTION=BINOMIAL LINK=LOGIT
/FIXED EFFECTS=Rab Between Rab*Between USE_INTERCEPT=TRUE
/BUILD_OPTIONS TARGET_CATEGORY_ORDER=DESCENDING
INPUTS_CATEGORY_ORDER=DESCENDING MAX_ITERATIONS=100 CONFIDENCE_LEVEL=95
DF_METHOD=SATTERTHWAITE COVB=MODEL PCONVERGE=0.000001(ABSOLUTE) SCORING=0
SINGULAR=0.000000000001
/EMMEANS TABLES=Rab COMPARE=Rab CONTRAST=DEVIATION
/EMMEANS TABLES=Between CONTRAST=NONE
/EMMEANS TABLES=Rab*Between CONTRAST=NONE
/EMMEANS_OPTIONS SCALE=ORIGINAL PADJUST=LSD.
best
Diana
_____________________________________ Professor Diana Kornbrot Mobile +44 (0) 7403 18 16 12 Work University of Hertfordshire College Lane, Hatfield, Hertfordshire AL10 9AB, UK +44 (0) 170 728 4626 <+44%201707%20284626> d.e.kornbrot at herts.ac.uk<mailto:d.e.kornbrot at herts.ac.uk> http://dianakornbrot.wordpress.com/ http://go.herts.ac.uk/Diana_Kornbrot skype: kornbrotme Home 19 Elmhurst Avenue <https://maps.google.com/?q=19+Elmhurst+Avenue+%0D%0ALondon+N2&entry=gmail&source=g> London N2 0LT, UK +44 (0) 208 444 2081 <+44%2020%208444%202081> ------------------------------------------------------------ [[alternative HTML version deleted]] _______________________________________________ R-sig-mixed-models at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models _______________________________________________ R-sig-mixed-models at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-sig-mixed-models _____________________________________ Professor Diana Kornbrot Mobile +44 (0) 7403 18 16 12 Work University of Hertfordshire College Lane, Hatfield, Hertfordshire AL10 9AB, UK +44 (0) 170 728 4626 <+44%201707%20284626> d.e.kornbrot at herts.ac.uk http://dianakornbrot.wordpress.com/ http://go.herts.ac.uk/Diana_Kornbrot skype: kornbrotme Home 19 Elmhurst Avenue <https://maps.google.com/?q=19+Elmhurst+Avenue+%0D%0ALondon+N2&entry=gmail&source=g> London N2 0LT, UK +44 (0) 208 444 2081 <+44%2020%208444%202081> ------------------------------------------------------------ _____________________________________ Professor Diana Kornbrot *Mobile* +44 (0) 7403 18 16 12 *Work* University of Hertfordshire College Lane, Hatfield, Hertfordshire AL10 9AB, UK +44 (0) 170 728 4626 <+44%201707%20284626> d.e.kornbrot at herts.ac.uk http://dianakornbrot.wordpress.com/ http://go.herts.ac.uk/Diana_Kornbrot skype: kornbrotme *Home* 19 Elmhurst Avenue <https://maps.google.com/?q=19+Elmhurst+Avenue+%0D%0ALondon+N2&entry=gmail&source=g> London N2 0LT, UK +44 (0) 208 444 2081 <+44%2020%208444%202081> ------------------------------------------------------------