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.
645
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4 views
Submitting Lasso Results For Publication
I am creating a model to predict cost of a particular surgery. I have n = ~20,000 and have >300 variables to choose from. I decided to use a 5 fold cross validation Lasso approach in SAS (proc ...
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6 views
PROC GENMOD Repeated Measures in SAS [closed]
I'm trying to run an analysis on a repeated measures anova. The study was nine months of data. Four treatments was applied to 3 separate blocks and the result is average cover of native plant species. ...
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17 views
Should I use fixed or random effects?
I have a healthcare data set with one (six meter walk test) and two predictors (baseline six meter walk test as a covariate, and days of treatment). We want to know if 6MWT improves over time (using ...
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12 views
Including all treatments in crossover design mixed model in SAS
I have a dataset effects of 3 treatments against ctrl on cell-lines collected from 4 donors.
...
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12 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:
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1answer
22 views
logistic mixed model very large standard error
I'm running a logistic mixed model (in SAS) and these are my results:
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3
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1answer
54 views
How to add error bar plots into a parameter table?
I saw a very neat and clear table in this paper https://link.springer.com/article/10.3758/s13421-018-0797-5:
As shown above, the authors added error bars of parameter estimates into a table, which ...
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7 views
Exact logit but for multinomial or conditional logit?
Logit uses MLE, which exhibits bias in small samples.
As a result there is a procedure "Exact Logit" that I believe uses a method different than MLE to account for this.
Is there something similar ...
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1answer
81 views
Evaluating the importance of a unit-root
I have a monthly time series and I'm trying to determine if such set of data is stationary or not; the dataset is about composed by 160 record.
Specifically, I'm running 2 test found in literature:
...
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1answer
11 views
What is the best way to examine the interaction between student gender at level 1 and instructor gender at level 2 in a multilevel model?
I am building a multilevel model with students at level 1 and instructors at level 2 and I have variables at each level to indicate the gender of the students and their instructors (see coding below). ...
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8 views
How to solve heavy-tails error terms in a linear regression model
I am doing a linear regression model using SAS. After box-cox transformation of the outcome variable from wage to lwage (log of wage). The residuals plot still not normally distributed. How to solve a ...
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0answers
11 views
How can I verify the linear hypothesis in a multiple logistic regression using SAS?
I have a multiple logistic regression where 2 of my independent variables are continuous. The rest are dichotomous. I am supposed to verify the linear hypothesis for the continuous variables. Is there ...
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15 views
Why in SAS proc glm, the SE of a difference just simply takes on the larger SE of the two means in comparison?
In SAS proc glm (simple one-way ANOVA), I noticed the SE of differences do not correspond to widely circulated uncertainty propagation technique (e.g. any variation of quadrature summation, pooled ...
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28 views
Converting SAS model to R model: treating intercept as random term
I have a binomial data set in SAS with the following column names:
loc, trt, succ, fail
I want the response to be the proportion of success, so in my data statement I have total = succ + fail
My ...
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0answers
18 views
Scaling credit risk scorecard
I need to build a credit risk scorecard using logistic and linear regression. The variables using to predict are all dummies, where each dummy is a bin of some variable. Let's say the variable age, I ...
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1answer
11 views
internal process of proc mianalyze procedure [closed]
Does proc mi analyze in sas consider only estimates of imputed values or complete data sets that is imputed values as well as non imputed values?
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1answer
37 views
Poisson Regression with overload of zeroes SAS
I am testing different models for the best fit and most robust statistics to my data. My dataset contains over 50000 observations, approx. over 99.3% of the data are zeroes - such 0.7% are actual ...
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1answer
33 views
Can SAS Least Squares Means estimation algorithm be translated for a design matrix in Reference coding?
My question is whether itās possible to compute lsmeans defined in this SAS algorithm if the design matrix is not in GLM form. In particular, in R, if one feeds that design to model.matrix(), then ...
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0answers
18 views
Interpreting Ljung-Box white-noise test p-value
Good evening all, I am having some trouble understanding the Ljung-Box white-noise test p-value from SAS Forecast. So there are lags where the p-value exceeds 0.05, meaning that we fail to reject the ...
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1answer
21 views
Getting unexplained negative coefficient in Logistic regression using SAS
I am using SAS in order to predict the probability that a borrower will default on his loan based on his age group.
The variable age is divided in to 4 age groups.
group 1 has 1315 customers and out ...
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62 views
How do I interpret parameter estimates in additive exponential smoothing?
I am trying doing a course on time series forecasting and did a forecast for an airport arrival on SAS forecast studio. Additive exponential smoothing is used for my choice of forecasting. How do I ...
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0answers
16 views
Could lower limit of a confidence interval be negative?
I am using proc glimmix in sas to find the effect of the different urine tests taken with one diagnostic urine test, called urine LAM test. I use least squares mean to find the point estimates and ...
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1answer
44 views
Difference in differences without a control group
I am interested in learning how to do a difference in differences without a control group using SAS.
In my data, everyone has been affected by the exposure (policy change), is it even possible to do ...
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45 views
How to estimate the n-year Hazard Ratio from PROC PHREG
Dear SAS users in the CV community:
I am using the sample data publicly available at:
https://stats.idre.ucla.edu/wp-content/uploads/2016/02/whas500.sas7bdat
The tutorial is found here along with a ...
6
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1answer
41 views
Logistic regression when there are more than one observation for each subject
I have a data for the urine test results. Two samples have been taken from each patient in different days and tested by the LAM test and urine dipstick for different biomarkers.
The data looks like ...
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18 views
appropriate error term for a randomized complete block design, possible split plot in time, with subsamples (in SAS PROC MIXED))
I am analyzing the results of an agricultural experiment, as follows:
Plots are laid out in a randomized complete block design with 3 replications. They have been either conventionally or organically ...
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23 views
What is the equivalence of BETWITHIN degrees of freedom in mixed-effect models R?
As in the title. Let's assume I cannot use the Kenward-Roger or Satterthwaite method in mixed-effect models. I was told to use the BETWITHIN method. Now I switched to R. I can use any package I want. ...
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0answers
49 views
Why cannot the sandwich SE be used when the Kenward-Roger denominator df are in use?
This question is about mixed models, and the use of both the Kenward-Roger correction (K-R) for small sample sizes and robust (sandwich) estimators for standard errors in the same model. Is it ...
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37 views
how to determine a priori probability distribution of sigama2 in montecarlo simulation?
1ćthe monte carlo simulation code in SASļ¼
Example1:
https://support.sas.com/rnd/app/stat/examples/BayesStd/new_example/index.html
...
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0answers
106 views
O'Brien Fleming Interim Analysis Interpretation with PROC SEQDESIGN
Quick question about the output of PROC SEQDESIGN. I was playing around with the O'Brien Fleming method trying to understand how we can interpret the results spit out by SAS for a mock study with ...
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0answers
130 views
“Back-casting” a Time Series
The problem I have is that i have a series of data (between 2000-2010) and i have another series (independant variable) which is available between 1980 and 2010. I need to backcast the value of the ...
2
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1answer
61 views
Replicate Stata 'variance' and 'robust' in R for mixed effects methods [closed]
I am working with a small dataset of clustered data. The experiment is on mice, testing the efficacy of a substance for neurons cells within mice, and delivery of a fatty acid substance between mice. ...
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24 views
LSMeans for repeated measures using GLM in SAS
I would like to obtain LSMeans comparisons for the within-subject factors of a repeated measures model using GLM.
Here is an example
...
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2answers
43 views
Split plot design with psudo replicates
I am working on a project and need to analyze data that I know is an example of a split plot design but I am having trouble setting the model up correctly.
Here's the situation:
A bakery is testing ...
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0answers
36 views
Logistic Regression Residual Analysis in R (replicate influence command from SAS)
I'm looking for a quick reference on how to do some residual analysis for logistic regression in R. Oddly enough, this has not been easy to find.
The data set I am working with is the Add.dat which ...
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16 views
SUR and cross equation restrictions in SAS
I am estimating a system of three equations using the option SUR in syslin procedure.
Code:
...
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30 views
Different results for Cox regression
I am trying to get my head around Cox regression. I found quite a good paper on the subject by R. Tibshirani: A plain man's guide to the proportional hazards model.
On page 67 he gives a toy example, ...
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9 views
Python lime on model from SAS
I have a gradient boosting model crated in SAS. I want to use python-LIME to look at local explanations for some of the cases (We don't have the lates SAS Viya platform where LIME is available). Is ...
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2answers
25 views
Factor expressed as standardised variable in factor analysis
I know that in principal component analysis, we can express PCs as a linear combination of the variables, but is it possible to do that for factors in factor analysis?
For my task I am given a ...
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0answers
77 views
Equivalence of proc mixed SAS and R lme/lmer
I am looking at a 2x2 crossover study with period-specific baseline measurements and the according post-treatment outcome values
Intervention (A or B)
Sequence (AB or BA)
Period (visit day1 and visit ...
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1answer
36 views
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1answer
66 views
Inquiry: Obtaining equivalent results between binom.test() in R and Proc Freq?
Problem
I am reading the Wikipedia article on the binomial test and I have been unable to duplicate the purported R and SAS code showing they are equivalent.
The p-value I get for R code is ...
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107 views
Estimated coefficients after SAS glmselect with Lasso
I did run a lasso logistic regression with SAS glmselect (Y=1 for event and Y=-1 for non event). My syntax is something like:
...
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35 views
Loan Vintage balance forecast
I have a Monthly Vintage level balance data from 2013-Jan at each Time on books/Month on books ( TOB_calculated). What is the best approach to project loan balance for the next 17 months for each of ...
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10 views
Define optimal Data Volume for Model Development Population?
I would like to ask and learn some approaches, analyzes about representativeness of modeling data. I want to know what is the optimal date range for model development population?
I want to ask that ...
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28 views
Discarding Observations during time series analysis
I'm studying Economics and we use SAS as our programming software. What I did notice is that with the AR and MA process we usually work with 250 observations. What confuses me though is the lecturer ...
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1answer
67 views
Time Origin in Survival Analysis
I am new to survival analysis, and I am confused about time origin, or what's called calendar data format and survival data format.
I have the following dataset, subjects were continuously entering ...
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1answer
82 views
P for trend test in multivariate analysis
I'm trying to analyze dose-response using trend anlysis in SAS.
In 2*2 table analysis, we can use Mantel-haenszel test with proc freq.
However, several study ...
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3answers
403 views
How does SAS compute standard error
I need help with estimated standard errors in SAS. I'm doing logistic regression of and I obtained the score, standard error, pd and lower and upper limit of confidence interval. I also computed these ...
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54 views
Suvival Analysis - Need Help with Converting SAS code to RStudio [closed]
In the past I have used the following SAS code to perform survival analysis for the purpose of predicting retirement.
...
