All Questions
Tagged with sas generalized-linear-model
34
questions
2
votes
0
answers
582
views
Very different results between R and SAS for negative binomial model
I am getting very different results for a negative binomial model between R and SAS. Can you please suggest as to why is this happening? I am not able to add a csv file used as the data.
R script:
<...
- 63
1
vote
1
answer
465
views
How to interpret this SAS poisson regression output?
I have a dependent variable being positive, discrete (number of people migrated) and the independent variables are all continuous. I want to study the impact of the independent variables on the ...
- 405
1
vote
0
answers
57
views
Validity of setting Singular=1 in proc GLM Contrast statement (SAS)
I am running a proc GLM in SAS with specific contrasts, one of which is included in the code below. With the following code, all my contrasts are always unestimable:
...
- 229
1
vote
0
answers
113
views
How to interpret the beta estimates of a generalized linear model with a square root power link?
I'm running a generalized linear model (GLM) in SAS with a gamma distribution (since my Y response variable is skewed to the right) and a specified square root power link (since I found that ...
- 11
0
votes
2
answers
2k
views
Difference between PROC REG , PROC GLM, and GENMOD
Can anyone give me a very simple explanation of each? I have no previous statistical background - what would be examples to use each?
Thank you. Apologies if this is very broad but I cannot decipher ...
- 367
1
vote
1
answer
43
views
Calculate risk between classes
I am doing some exercises about logistic regression with SAS and I need to calculate and interpret odds.
For calculating the individual probabilities I use those formulas:
While later, the Professor,...
- 123
2
votes
0
answers
290
views
SAS and R gives different standard error when fitting Tweedie model
I would like to fit a Tweedie GLM to the data. However, even though PROC GENMOD from SAS and glm() from R gives the same coefficient estimates, they give quite different standard error. What it the ...
- 1,716
2
votes
0
answers
201
views
Insignificant “time variable” in GLM?
I'm used to GLM modelling with a time variable, eg. Month or Year, main reason being it is often used as a proxy for an immeasurable variable, or simply data you can not easily obtain, econometrically ...
2
votes
0
answers
1k
views
Calculating Effect Size for Generalized Linear Models
I have measured spore production by a parasite after feeding the host on 4 diets of varying nutritional content. I have primarily analyzed the data by treating the diets as categorical variables, even ...
0
votes
0
answers
204
views
Strategies for model selection of non-nested GLMM models
What are the best strategies to select between a small collection of possible models when the models are non-nested and modeled using a GLMM with correlated residuals (longitudinal random effects or $...
- 1,145
5
votes
1
answer
326
views
In SAS, does the using the GLM statement ABSORB invalidate the standard errors of the parameter estimates?
SAS provides a handy tool for handling panel models with a large number of groups by 'absorbing' those groups (PROC GLM; ABSORB). My understanding is that it factors the effect of the absorbed ...
- 51
3
votes
1
answer
1k
views
Fit a linear mixed model with only 1 group
In R, is it possible to force a lmer model with random effect to be fitted on data with only one level? We want to do this to keep the same model structure in rare case where our data only contains 1 ...
1
vote
0
answers
114
views
Inflated Odds Ratios in a Mixed Effect Logistic Regression
I have a dataset with approximately 40,000 observations, which are dependent, coming from around 30,000 subjects. Most subjects has 1 observation, some have 2, a minority has 3, while 4 is rare. The ...
- 486
0
votes
1
answer
1k
views
When fitting Tweedie GLM in SAS, should I use the scale option?
In SAS proc genmod with dist=tweedie, when would you use scale=pearson or ...
- 1
3
votes
1
answer
6k
views
glmer in R to recreate GLIMMIX from SAS
I am trying to recreate a PROC GLIMMIX command in R using glmer. Here is a link to the data (from SAS product support GLIMMIX documentation): https://support.sas.com/documentation/cdl/en/statug/63033/...
- 31