Questions tagged [sas]
SAS is a statistical software package. Use this tag for any on-topic question that (a) involves SAS either as a critical part of the question or expected answer, & (b) is not just about how to use SAS.
698
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Reconciling differences in CI calculated between SAS and R on same dataset
I have been given a brief of replicating statistical analysis which was done previously to verify results. Data being collected are body weights of male and female mice over 20 weeks, given a ...
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38
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Both Shapiro-Wilk normality test results are non-parametric
I have 2 resuls from normality testing via Shapiro-Wilk test:
and .
If I understand correctly, both have p > α = 0,05 which indicates that both have normal distribution. So for my next analysis, ...
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9
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Which type of quantiles are safest to report in R?
With this topic in mind: If there is no censoring, can be the naive 3rd quantile different from the one calculated with from the Kaplan-Meier?
I'm wondering which one is the safest option. Of course I ...
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15
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How should I conduct repeated ANOVA if I have multipe group within a person?
I have dataset like follows:
In this case, I want to compare the mean difference between A, B, C. Should I conduct repeated ANOVA?
...
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7
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Degrees of Freedom for Variances in SAS Proc MIXED
Below is a SAS proc Mixed code generated by JMP. Both JMP and SAS give me a confidence interval for the variance components (in the table "covariance parameter estimates"). I would like the ...
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1
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46
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What happens to zero values during statistical model estimation with a log link function? (SAS PROC GAMPL - GAM)
I fitted a generalized additive model (GAM) using SAS PROC GAMPL with a Poisson distribution and a log link function.
The outcome was a measure of repair cost for a large collection of units (4k+). ...
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1
answer
35
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GEE - ROC Curves the Same Using Different Cluster Variables
I am creating multiple GEEs with the same covariates, but I am testing different clustering variables. The outcome is a binary yes/no variable and both VAR1 and VAR2 are binary, as well. Patients can ...
- 57
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40
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Interpreting random effect with multiple random intercepts in SAS proc glimmix
We want run an event history analysis using logistic regression in SAS proc glimmix. We want to specify three random intercepts and we are using following code:
...
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22
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Need help obtaining Cov Parameter Estimates in PROC GLIMMIX
I'm really struggling with something that should be a simple solution but for the life of me, I've been struggling for a while now trying to figure it out. I apologize in advance for my lack of ...
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21
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GEE Explained Variance is Negative
I am creating a series of GEE models and a couple of statistics I normally report are the ICC and the explained variance for both Level 1 and Level 2 of the model. However, I am calculating that for ...
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22
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Time-dependent Categorical Covariate in PHREG
I am struggling to use PHREG with time-dependent variables using the "programming approach" (vs. the counting approach).
Rather than go into the details this is the general idea. I have a ...
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32
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lmer (R) and proc mixed (SAS)
Recently I have been working on replicating the results from package lmer in R to proc mixed in SAS for mixed modeling. There are multiple model structures that you ...
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1
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35
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Biplots in R vs in SAS, does the scale parameter differ?
When reading up on biplots in a principal component context, I found that in SAS setting c = 0 gives you a GH biplot that represents the vectors correctly.[1]
The same applies in STATA.[2]
From what I ...
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11
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How to include replicate weights in McNemar’s Test [marcro with base weight included]
I'm trying to use the macro in this documentation (https://support.sas.com/resources/papers/proceedings/pdfs/sgf2008/382-2008.pdf)
with replicate 80 replicate weights , wt01 to wt80. The macro below ...
- 153
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14
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Identifying groups with better response to treatment
We have tested a population (splitted in test 50% and control 50%) with a treatment. Overall, the treatment was effective - our test variable was significantly different in the treatment and control ...
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7
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SAS How to conduct paired t-test on off diagonal cells (proc surveymeans)
How to conduct paired t-test on off diagonal cells (proc surveymeans)
Posted 45 seconds ago (3 views)
Hi,
I'm trying to compare same users' response in two separate years. There are many ways to ...
- 153
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1
answer
41
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Weights for estimating ATE (rather than ATT) in SAS %CEM macro for coarsened exact matching?
I'm running Gary King's %CEM SAS macro (available here) for coarsened exact matching (CEM) for a project at work.
The macro works fine for estimating the Average Treatment Effect on the Treated (ATT) ...
- 4,504
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17
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How to weight my data in SAS - categorical and numerical variables
I've collected data from 1000 animals (categorical and numerical variables) from 2 different farms. My problems are: one farm corresponds to 68% of my data, in some of my variables I've observed more ...
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42
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AUC and misclassification rate [duplicate]
why do you think that is possible? I compare decision tree with neural network in SAS EM and it chooses DT as the best model, based on misclassification rate, I guess. But AUC is higher for neural ...
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21
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Pre-post model for ordinal outcome
I have outcome data collected at baseline and at one year follow-up. The responses are ordinal, with 0=better, 1=somewhat better, 2=somewhat worse, and 3=worse. My colleague is interested in seeing ...
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27
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Mediation analysis with covariates SAS
I am conducting a mediation analysis to analyze the effects on moral reasoning towards AVs. I already detected a suitable mediator and do now want to examine the effect of possible covariates (age, ...
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2
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50
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In Survival Analysis, does "Non - Cumulative" Hazard Exist?
In the context of Survival Analysis, I have seen that the standard (non-parametric) estimate of the Hazard Function is through the Nelson-Aalen Estimator :
As seen from this formula, the Nelson-Aalen ...
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9
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1
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1
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105
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SAS: Flat line forecast ARIMA model?
I'm trying to forecast a large dataset using ARIMA (The data does not have seasonality), I ended up getting an ARIMA(2,1,2) model where the log of volume was taken due to increase in variance over ...
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37
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Large dataset time series model help!
I'm doing a time series project on quite a large data set based on the stocks of a company over time. The first image shows quite a large increase in variance over time and suggests the series isn't ...
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1
answer
105
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How to construct probability plots for survival distributions in R? An example plot from SAS
Hello I am performing survival analysis I really like SAS's probability plots from lifereg as a way to visualize a distributions' fit and was curious if there is a way to do it in R? Here is the ...
- 105
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22
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It should be analyzed as Split-plot design or split-split plot design?
I have a field experiment with 4 blocks as shown in figure (1 block shown). I want to see the effects of Plant desity, spacing and irrigation. I am not sure how to analyze it.
Should it be treated as ...
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19
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Cumulative incidence vs Cumulative hazard: What's the difference?
Does anyone know what he difference between the 2 is? I want to calculate the cumulative incidence, but all I see is cumulative hazard in SAS.
2
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answers
231
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Negative Eigenvalues in EFA
Assuming a set of data meet all assumptions for EFA and we are doing a factor analysis (with the SMC used to define the shared variance), how do negative eigenvalues appear and what does that say ...
- 375
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31
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Heckman sample selection model
Instead of using a Heckman correction two-step solution, I used a one-step solution by means of multiple equations via SAS PROC QLIM.
Is it true that when using a Heckman correction model all ...
0
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0
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8
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Should I worry about a really small estimated G-matrix?
I am running cross-interaction with a generalized multi-level model (2-levels) with a Poisson distribution in SAS. I have a random intercept and a random slope as one of my predictors is time-varying. ...
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0
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55
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Restricting model parameters estimates to control the weights in logistic models in python/R
Referring to a similar problem as Restricting model parameters in logistic models in R, is there a method such that I can impose constraints on parameters for a logistic model in either ...
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3
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1
answer
129
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SAS and R survival package have different confidence interval estimates. Why?
Hello I am learning about Survival Analysis and I noticed that SAS and R survival package produce different confidence interval estimates for the median Survival ...
- 105
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0
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89
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Conditional Logistic Regression vs Stratified Cox Regression
I am working with matched case and control data (1:2 matching). And the outcome is binary. In this case, conditional logistic regression can be used to run analysis. To my knowledge, cox regression ...
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4
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1
answer
64
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Biostatistics book suggestion
I am a statistical programmer and am working on SAS in a pharma company.
Also I have masters in statistics and have interest in the subject.
Can anyone suggest me books on biostatistics, helps in SAS ...
1
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1
answer
194
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When is it valid to use lasso and adaptive lasso
I am brand new to LASSO. I have a problem in that I have a data set without about 440 usable cases only about 42 of them of one level of the DV (every level of the DV and predictor have two levels). I ...
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2
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210
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Is it worth it to consider a MS Business Analytics program that is heavily focused on SAS? [closed]
I'm completing my undergrad this year and I've finished my graduate applications. I've been accepted to Oklahoma State University MS Business Analytics and Data Science. Looking through the ...
2
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1
answer
73
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How do I choose which confident interval for proportion difference to use in SAS?
In SAS, there are different CIs for proportion difference ($\pi_1-\pi_2$) to choose?
1.Continuity-corrected Wald CIs based on normal approximation
2.exact method
3.Miettinen-Nurminen CIs based on ...
5
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1
answer
336
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Has R fluency overtaken SAS in terms of being more popular as a hiring requirement? [closed]
Seems like when I first graduated (was a while ago, life went in a different direction and I wasn't an analyst for long), almost all the job listings wanted SAS? While R had only got limited traction ...
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1
answer
57
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How to analyze proportions data: Does the proportion of spent time in option A differ from the proportion of time spent in option B?
My research question is whether sheep prefer lying down on straw bedding (option A) or on a new type of bedding (option B). If sheep spent more time lying down on one option, we will say they have a ...
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1
answer
50
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glmer (R) versus SAS output random effects
I have a binomial glmm model which I have analysed in both SAS and R. However, I have noticed a difference in the statistics which are given for the random effect. In SAS, there is a table called '...
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1
answer
22
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Comparison between two groups of time series?
I have two groups of people. One group of people are healthy and the other group of people is sick. For people in both groups, I let them do exercise for 10 mins and then let them rest for 3 mins. I ...
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76
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Reference books for mixed model
I am looking for reference to get a better understanding and overview of the mixed models. My goal is to understand the basic concepts and the formulas behind different models (I am having a hard time ...
0
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0
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142
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Multinominal conditional logistic regression
I have a dependant variable that comes with 3 categories A, B, and C, and I want to fit a multinominal logistic regression for an exposure variable, along with some confounding factors.
In order to ...
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Why would SAS proc mixed produce residual variance estimates under AR1 covariance structure, but none for unstructured covariance?
I am working on a program in SAS that seeks to extract r2 based on the residual variance produced by covariance parameter estimates in PROC MIXED.
The specification ...
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vote
1
answer
150
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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 ...
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1
answer
213
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What's the difference between Average Square Error and Mean Square Error ? Are they the same thing?
I have a bit of confusion regarding ASE and MSE as in SAS Enterprise Miner it shows these two measurement scales. What is the difference or similarity between the two and why are they both so similar? ...
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2
answers
91
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Material/courses for analyzing very large data sets
I am looking for good materials to learn more about analyzing very large data sets, say 5 million observations, with a reasonable computational time (say less than 10h).
My main interests is ...
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0
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42
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SAS: joint model with proc glimmix
I am attempting to perform a joint generalized linear mixed model with one binary variable and one continuous variable with proc glimmix. The preferred random effects structure for my binary variable ...
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182
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How do you solve this error Within-imputation Estimate missing for effect ... in the input PARMS = dataset.?
I am fitting a mixed-effects logistic model using PROC GLIMMIX. All the variables I am working with are either binary of categorical. Because there were a few variables that had 10% or more of missing ...
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