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Questions tagged [gamlss]

Generalized additive models for location, scale and shape (GAMLSS).

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GAMLSS - How to adjust AIC for log-transformation of variables [duplicate]

I have one GAMLSS model in which the independent and dependent variable are on the natural scale, and a second model in which both variables have been log-transformed. How do I adjust the AIC of the ...
Peder Holman's user avatar
2 votes
1 answer
31 views

Expression of estimated standart deviation in GAMLSS model

I'm trying to replicate the results of the North Carolina Birth Data Analysis in the paper A Bivariate Copula Additive Model for Location, Scale and Shape by Giamperro Marra and Rosalba Radice (https:/...
Raheshi Knuwga's user avatar
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NA's in the working vector or weights for parameter sigma in gamlss call with exGAUS family

I am trying to fit standardized reaction time data to an ex-gaussian distribution with gamlss. In most cases the below code works fine (see rt_std1) and outputs the required ex-gauss parameters. In ...
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3 votes
1 answer
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Density Forecasts with GAMLSS

Does someone know the function to create density forecasts within the GAMLSS Package? The predict. Formula is not the right one. Predict do Point Forecasts
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Why is gamlss fitting distributions which do not fit and are not feasible?

I have the following example using gamlss to fit optimal distributions. z0 are random variables of normal distribution with mu=1 and sd=2. z1 should fit the best ...
karl's user avatar
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2 votes
1 answer
124 views

How to interpret the p-value associated with the intercept?

I ran a gamlss to predict my response variable Y with 2 categorical factors PROTECTION and JOUR ...
Marie Guittonneau's user avatar
1 vote
1 answer
40 views

Interpretation of estimates for a model with 2 categorial factors

I ran a model with 2 fixed factors that are categorial: Ind: 10 levels CRENEAU: 4 levels For the parameter nu (I am running a <...
Marie Guittonneau's user avatar
1 vote
1 answer
57 views

Difference between ZIP and ZIP2

I am wondering about the difference between ZIP and ZIP2 distributions in the gamlss package. I read, in the gamlss documentation, that The ZIP2 is a different ...
Marie Guittonneau's user avatar
1 vote
1 answer
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Interpretation estimates of a gamlss with 2 categorials fixed factors

I want to know if my response variable "Ratio" is influenced by 2 fixed factors : "Protection" and "essai" Each experimental units has one level of ESSAI and one level of ...
Marie Guittonneau's user avatar
1 vote
1 answer
244 views

How to interpret nu and tau in GAMLSS BEINF?

My response data is a ratio going from 0 to 1, inflated at 0 and 1. My aim is to build an explanatory model to test the influence of PROTECTION and JOUR (categorical fixed factors) on the response ...
Marie Guittonneau's user avatar
1 vote
0 answers
120 views

GAMLSS model can't compute vcov using family BEINF0

I am using gamlss to analyze inherently proportional data for % mildew on leaf area. This is an average value of 10 leaves per replicate. I only have 3 replicates. I used BEINF0 for some datasets that ...
Maripaula Valdes-Berriz's user avatar
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1 answer
140 views

GAMLSS: What exactly is the predicted or fitted sigma? why can't I use it to calculate z-score?

The question I have is previously posted here in detail by someone else but the main question is not answered. what exactly is the fitted sigma? Is it always standard deviation? If yes, why can't it ...
9id9's user avatar
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How to relate prevalence to factors with multivariate analyses model (GAM beta inflated)?

While analizing the prevalence of cows to brucellosis (illness), and in order to relate it to a set of factors like country, state, and detection technique, I need to apply a multivariate analysis ...
Adonis Cedeño's user avatar
2 votes
1 answer
124 views

Interpreting predict() with gamlss() and beta-binomial family=BB

Note after answer is posted: The issue here was actually about formatting the data of the dependent variables in the formula when using (beta-)binomial families. Not about ...
John K. Kruschke's user avatar
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1 answer
223 views

Which distribution to choose in a GAMLSS model

I am trying to model the following continuous variable (its distribution shown in the image below) through a GAMLSS according to different variables. The question I have is how to choose the type of ...
Lander's user avatar
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1 answer
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Understanding Ridge regression for GAMLSS

I am trying to understand the mathematics behind Ridge regression for parametric GAMLSS. As I understand so far, it introduces a penalty term defines as $$\text{Penalty term}=\lambda \sum_{j=1}^{J_k} \...
Emma Kathrine Kokborg Iversen's user avatar
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1 answer
23 views

How to compare GAIC of linear model and other GLMS?

my dataset can be found here: https://raw.githubusercontent.com/yuliaUU/test/main/test.csv ...
yuliaUU's user avatar
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2 votes
1 answer
302 views

Termplots in GAMLSS

I am interested in plotting the marginal effects in my GAMLSS model. However, what puzzles me a bit is that when using the term.plot() function from the ...
the_cake_is_a_lie's user avatar
1 vote
1 answer
161 views

Standard errors in GAMLSS vs LMER

Why do the standard errors for gamlss are much lower than the standard errors from lmer? ...
Márcio Augusto Diniz's user avatar
1 vote
1 answer
105 views

Choosing whether to eliminate or keep a predictor in a GAMLSS model

I need to calculate the centile curve for y using a GAMLSS model with age and height as predictors. The plots below depict the relationship between log(y) and each of the independent variables. I ...
stats's user avatar
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1 vote
1 answer
112 views

How to find the appropriate model to apply (GAMLSS)/Approving statistical thinking

I need to compute percentile curves using the LMS method (from the GAMLSS package/models) with Age and Height as predictors. What is the best way to determine which equation (with which transformation ...
stats's user avatar
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Need some help to identify the appropriate distribution

The residual plots of the following models are not normal, while the distribution of residuals between (-3 to 3) is normal in model m17. The worm plot of all equations appears to be correct. The goal ...
stats's user avatar
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1 answer
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Find the more appropriate fit by using term.plot in GAMLSS

I'm comparing several GAMLSS models and was wondering how I might use the term.plot to identify the best model/fit. What type of information can we get from this graph? Can I argue that the model with ...
stats's user avatar
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2 answers
96 views

qBCCGo function in GAMLSS package (quantile function)

I am working with GAMLSS technique and I use LMS (with three parameters of mean,variation and skewness) method. I found the follwoing formula to calculate the lower limit of normal as the link ...
stats's user avatar
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3 votes
1 answer
207 views

How to compare centiles from different models?

I am comparing the centiles from different GAMLSS models. Which model has a better performance. Why? For model 1, the number of cases below 0.4 centile is 0.5. Is this possible? The number of cases ...
stats's user avatar
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1 vote
0 answers
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A question about applying GAMLSS models

I want to make the growth chart by using age and height as predictors. As the scatter plots show a nonlinear relationship between age and y, I need to use the P-spline to make the statistical equation....
stats's user avatar
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1 answer
77 views

Proportion/Ratio response variable

I need some advice to understand the following code. We are working with lung data and usually we use LMS technique to calculate the reference curves. In order to calcualte the curves with LMS method ...
stats's user avatar
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4 votes
2 answers
619 views

Robust options to fit GLM or GAM for overdispersed Poisson counts (quasipoisson or negative binomial) in R

It appears glmrob from the robustbase library does not support quasipoisson or ...
Tom Wenseleers's user avatar
2 votes
1 answer
78 views

Is it possible to do meta-regression with GAMLSS?

I am about to conduct a meta-regression analysis to fit some age-related changes. Since the GAMLSS approach is highly suggested in the normal regression of such data, I want to apply GAMLSS to my ...
Jack Yang's user avatar
2 votes
1 answer
430 views

GAMLSS vs VGAM for percentile curves (Growth chart)

It seems that there are two methods and packages in R to calculate the Percentile curves based on LMS (Lambda for the skew, Mu for the median, and Sigma for the generalized coefficient of variation; ...
stats's user avatar
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1 answer
111 views

How to obtain the p-values ​of a gamlssMX model?

I am working with a dataset that includes a binary target variable (0 or 1). I have built a model with the gamlssMX() function included on the "gamlss.mx" package to explain a continuous ...
Sara Rodríguez Pastoriza's user avatar
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1 answer
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Identifying the appropriate model for determining the dimension with the most impact on poverty

I am working on a research to determine the dimension (health, unemployment, education and standard of living) with the most impact on poverty. The response variable is the decile score obtained for ...
Amos Nunghe 's user avatar
0 votes
1 answer
430 views

Error in post-hoc analysis on gamlss model with emmeans: "Error in V[idx, idx, drop = FALSE] : subscript out of bounds" [closed]

I am utilizing gamlss currently because of its flexibility in specifying 'rarer' data families but run into an error when trying to compare 2-by-2 differences in mu effects for my fixed model factors. ...
Simon Reynaert's user avatar
2 votes
2 answers
276 views

Creating nonlinear centiles/reference charts with longitudinal data

I have a continuous dependent variable measured for several thousand subjects. The dependent variable has been measured one or more times per subject at nonuniform points in time. I am looking to ...
cwb90's user avatar
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1 vote
1 answer
489 views

How to improve the fit of a beta zero-inflated regression model (GAMLSS)?

I'm working with a response variable with values between 0.0 and 1.0. I have a lot of zero. Thus, I'm using beta zero-inflated regression model. Specifically, I'm using the function gamlss from the ...
Alfonso Pineda's user avatar
0 votes
2 answers
166 views

can daily count data use GAM ordered categorical family, proportional-odds model?

The observed response variable Y takes on one of K(=21) ordered categories. Here is a summary of my response data (count data: the number of hospital admission in each day), y has observations across ...
Thomas's user avatar
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0 votes
4 answers
823 views

Betabinomial (BB) regression in the gamlss package (R)

I'd be grateful for any help with beta-binomial (BB) regression in the gamlss package: predictions from the fitted model of "mu" values for each observation in my data seem reasonable. But ...
Fraser's user avatar
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1 answer
180 views

How to use censoring at left point of zero in GAMLSS?

How do I apply GAMLSS tools to left-censored regression at a specific point? I know there exists gamlss.cens package, but it seems can not be censored at zero.
upuil's user avatar
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0 votes
3 answers
799 views

gamlss plot check

I used the gamlss to fit the model. Bottom right panel: Normal QQPlot of the quantile residuals. The plots suggest a slight left skewness of the quantile residuals. My questions is should this be ...
Thomas's user avatar
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1 vote
0 answers
70 views

ZINB boosting model (gamboostLSS) seems off in R, what could be the reason?

I have a dataset containing counts (values from 0 to 30) and different covariates. This is what the distribution of the count data looks like: After fitting a gamlss boosting model in R (with the ...
user333591's user avatar
2 votes
0 answers
392 views

Weibull distributed GLM with GAMLSS good fit?

I have data from a plant disease screen in a greenhouse. 145 plants in a greenhouse were inoculated with bacteria over the course of three days, and the amount of bacteria in the plant assessed at a ...
Thomas's user avatar
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2 votes
1 answer
442 views

Predict gamlss one-inflated beta model

How do you obtain predicted probabilities for the one-inflated component (nu model) of a one-inflated beta regression in gamlss? I have built the following model <...
Pat Taggart's user avatar
3 votes
0 answers
76 views

How to interpret a n-related change in coverage for model (simulation study)

I have repeated measures data from n_subjects where each has n_obs number of measurements before and after some intervention, ...
Rex Parsons's user avatar
3 votes
1 answer
383 views

Johnson SU distribution parameters values from R/rugarch

I have fit a GARCH model where I set the distribution to the Johnson's SU. I don't fully understand the distribution parameters returned by the model. To begin with, from Wikipedia, Johnson's SU is ...
s5s's user avatar
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1 vote
0 answers
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Residual autocorrelation in non-stationary (gaulss) model

I'm fitting a non-stationary model using mgcv (family: gaulss()) where the data have been collected at different points in space....
S. Robinson's user avatar
1 vote
1 answer
151 views

meanBEINF vs predict(model, type = "response') in BEINF GAMLSS. and determining odds of predictor variable coefficient

A variation of this question has been asked, but certain items remain unanswered - I am modeling the proportion of mortality (Prop) using a single continuous predictor variable which is temperature (...
user11057680's user avatar
1 vote
0 answers
99 views

Propensity Score Weighting in GAMLSS

in a project of mine i want to use a propensity score weighted gamlss model. However, the gamlss user guide states "In general using weights that are not frequencies is not recommended unless the ...
AStieb's user avatar
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0 votes
1 answer
257 views

How to transform an uniform distribution into a generalized beta 2 distribution using gamlss, fitdist or other?

Not comfortable with math and just R beginner, I get stuck on the following problem: Imagine that, for a variable ya (n=3000), the gamslss ...
denis's user avatar
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2 votes
0 answers
276 views

How to correctly specify and diagnose one-inflated beta regression mixed-models (using GAMLSS)

I would like to find out what variables influence/explain an efficiency score for an invasive species control method. As the score is defined on (0,1] and as some observations were not independent, I ...
Fanfoué's user avatar
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6 votes
1 answer
249 views

Regression with variance as outcome

Are there regression models where variance is the outcome, not mean? For instance, for interquartile range I may use quantile regression. But is there something similar for variance? For example, let ...
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