SAS is a proprietary cross-platform general-purpose statistical software package. [Official Website](http://www.sas.com/index.html)
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1answer
15 views
Clustering mixed variables in SAS
I have following variables in my dataset:
Working hours (numerical:ordinal)
Effectiveness (categorical:ordinal ; 4 values-> (poor,average,good,best))
Satisfaction (categorical:ordinal ; 4 values-> ...
48
votes
19answers
11k views
R vs SAS, why is SAS prefered by private companies?
I learned R but it seems that companies are much more interested in SAS experience. What are the advantages of SAS over R?
1
vote
0answers
59 views
Repeated Measures in R, SAS or SPSS: Whale Body Temperature Data
I have a question regarding a repeated measures experiment. I have 5 whales (randomly selected) that I recorded body temperature on. Data was collected via satellite, programmed to transmit records at ...
1
vote
1answer
38 views
ARIMA and external regressors in SAS and R
So I remember reading somewhere that when we have external regressors, auto.arima cannot make correct predictions for the order of difference for either ...
2
votes
1answer
588 views
SAS Proc Arima - DF, ADF, SIC, AIC, autocorrelation in residuals
I am using Proc Arima to produce the Dickey-Fuller and the augmented Dickey-Fuller tests. According to documentation Proc Arima uses the Dickey-Fuller method that tests the following hypothesis:
...
1
vote
0answers
32 views
Difference between GLM with intercept of subject VS repeated-measures ANOVA? [SAS code]
I've spent days trying to determine the difference between these two methods, which, as best I can tell, represent the univariate and multivariate approaches to a within-subjects design. Can anybody ...
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0answers
19 views
Different results from SAS PROC MIXED procedure and R lme function
I have 3(treatment)x3(period)x6(sequence) crossover design data. I have used SAS PROC MIXED procedure and I got the results with following code:
...
1
vote
1answer
101 views
R equivalent of Proc Nnpar1way with D option
I am trying to match SAS output with R. I am using Proc Npar1way with D option to get KS test statistic.
Here X is a binary ...
0
votes
1answer
193 views
How to calculate 95% CI for OR for a different reference category without running the SAS logistics again?
My question is about calculation of confidence interval (CI) for odds ratio (OR) from a SAS output of a logistic regression model for a different reference category without running the SAS program ...
0
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0answers
17 views
Proc GENMOD estimate statement with 2 continuous variables?
I'm testing an ordinal scale measuring dyskinesia (range=0-4) via proc genmod, with the independent variables in the model being Drug1 and Drug2. Both of these variables are continuous. I want to ...
1
vote
1answer
86 views
Pre-Post analysis with repeated measure
I've 50 subjects and ran an experiement 4 times for each subject and collected the pre and post vlaues for each run. I need to do pre post analysis. Here a sample of my data:
...
1
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0answers
16 views
Survival analysis in SAS-is there a way to include a random effect with interval censored data?
I'm trying to use some form of survival analysis (e.g. accelerated failure time or proportional hazards) to study seed germination time. My data is interval censored (also called "grouped-time") and ...
2
votes
1answer
75 views
Frequency ratio test with correlation structures
I have some data about two machines, each machine has 10-15 operation logs, and inside the log are the time-stamped status checks that takes on the value of 1 if ...
1
vote
1answer
53 views
2
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0answers
20 views
Comparing two different but related datasets
Background: I used a principal component analysis to re-define neighborhood boundaries. Each neighborhood is made up of at least 2 census tracts. There were 40 neighborhoods in my old model. I have ...
2
votes
1answer
229 views
Getting the good prediction standard error with R and/or SAS
Consider for instance the balanced one-way random effects ANOVA model:
$$(y_{ij} \mid \mu_i) \sim_{\text{iid}} {\cal N}(\mu_i, \sigma^2_w), \quad j=1,\ldots,J,
\qquad
\mu_i \sim {\cal N}(\mu, ...
4
votes
2answers
101 views
ARIMA — Residual autocorrelation is non-significant upto lag 6 and significant beyond lag 6
I tried to fit an AR(1) model and was examining the estimates of the model. I had a question on the output (ran in SAS - Proc ARIMA):
The residual auto-correlation up to lag 6 was non-significant (in ...
1
vote
1answer
49 views
How to analyze ordinal repeated measures data
I have data from an ordinal scale, with the score ranging from 1-4. Each subject has 9 assessments on this scale (study is a 9-way crossover design), and there are no missing data. What is the ...
1
vote
1answer
97 views
Backward selection in a Cox regression model
My goal is to fit a cox regression model in SAS, for which I use the PROC PHREG statement. As I am still new to regression methods, I would appreciate a little of ...
8
votes
4answers
265 views
Out-of-Core Data Analysis Options
I have been using SAS professionally for close to 5 years now. I have it installed on my laptop and frequently have to analyze datasets with 1,000-2,000 variables and hundreds of thousands of ...
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0answers
19 views
Reporting predicted outcome of mixed effects models
I am analyzing some group-randomized longitudinal trial data with three time points using mixed effects model. Some people missed 1-2 time points, and I didn't exclude any cases with missing dependent ...
0
votes
1answer
42 views
SAS and Principal Components Analysis
I'm new to SAS coding from SPSS point and click. I don't currently have SPSS, so SAS is my only option.
My question is: how do I get the percent variance explained and cumulative variance explained ...
7
votes
2answers
2k views
Difference between ridge regression implementation in R and SAS
I have been reading the description of ridge regression in Applied Linear Statistical Models 5th Ed chapter 11. The ridge regression is done on a data set available at body fat data
The textbook ...
1
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0answers
37 views
Avoiding the Generalized Variance Formula for the NYC Housing and Vacancy Survey
I am attempting to devise a replication-based survey design that closely replicates a taylor-series design used by the US Government publication - where I do not have access to all of the ...
3
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0answers
115 views
Are GAMMs/GLM the best choice for calculating number of germs on hands?
We would like your opinion on whether GAMMs are a good option and how best to go about implementing for the following:
During a period of patient care, a nurse will accrue $Y$ colonies of bacteria on ...
0
votes
0answers
62 views
How big of a dataset can R or SAS handle for regression?
On a standard computer (~3-6gb RAM) with 2 - 4 processors.
What are the size restrictions on a matrix of data for R or SAS?
2
votes
1answer
185 views
Profile likelihood confidence intervals
The theory behind profile likelihood (PL) confidence intervals (CIs) is clear to me. (See here, for example).
SAS is surprisingly quick in calculating the PL CIs for all the covariates in a given ...
7
votes
2answers
256 views
R as an alternative to SAS for large data
I know that R is not particularly helpful for analysing large datasets given that R loads all the data in memory whereas something like SAS does sequential analysis. That said, there are packages like ...
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1answer
36 views
What is the difference between estimate and contrasts in SAS?
I am having difficulty determining the difference between the two statements.
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0answers
20 views
Estimating Smoothing Parameters Simultaneously with Regression Coeffecients
I am developing a forecasting model that relies on a smoothed leading indicator. The indicator is the ratio of two smoothed series, and the forecasting regression equation uses a lagged value of the ...
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0answers
29 views
Degrees of freedom for mixed model
Using data and code the example from http://www.ats.ucla.edu/stat/sas/faq/anovmix1.htm:
...
-1
votes
1answer
105 views
Fault causal analysis
I have some time-series data, which deal with various incidents / asset failures / faults somewhere in the network that have an effect on performance (we call them Key Performance Indicators). Now, I ...
0
votes
0answers
45 views
What is the Survival Function using SAS LIFEREG with lognormal distribution?
I am trying to plot the survival curve using output from PROC LIFEREG with a lognormal distribution. Is my formula for the survival function (prob[i], where i is time) correct?
Below is my SAS code. ...
4
votes
1answer
343 views
Fitting a particular Gaussian model
Using R or SAS, I want to fit the following Gaussian model:
$$
\begin{pmatrix}
y_{1j1} \\ y_{1j2} \\ y_{1j3} \\ y_{2j1} \\ y_{2j2} \\ y_{2j3}
\end{pmatrix}
\sim_{\text{i.i.d.}}
{\cal N}
...
2
votes
2answers
146 views
Which are the correct sum of squares for repeated measures ? (balanced example)
Below are three ways to fit a MANOVA model in R and to extract ANOVA tables from the fitted model. The design is balanced. All methods give different results.
The data are 5 groups of 4 individuals ...
3
votes
1answer
197 views
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0answers
37 views
Media or market mix modeling?
Can anyone tell me how to build media mix model? Is it similar to market mix model?
What are the steps and variables in the model? If I want to build in SAS which procedure should I use?
1
vote
2answers
74 views
How to generate the time series from a given model?
we consider a sparse autoregressive time series of length 1000 obeying the model
X(t)=0.2X(t-1)+0.1X(t-3)+0.2X(t-5)+0.3X(t-10)+0.1X(t-15)+Z（t）
with nonzero coefficients at lags 1,3,5,10 and 15,where ...
0
votes
0answers
30 views
Experimental design & model
I'm testing the effect of land history and soil organisms on the growth of Stinging nettle.
To investigate the effect of land history ("hist") on growth, soil samples ("sample") were collected at 10 ...
7
votes
5answers
2k views
Is there an R equivalent of SAS PROC FREQ?
Does anyone know of an R equivalent to SAS PROC FREQ?
I am trying to generate summary descriptive statistics for multiple variables at once.
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votes
0answers
61 views
Frequency Table for Repeated Measures
I've 12 unique subjects, and in total I've almost 1700 observations.
I've an ordinal response variable (has 4 levels) and 3 categorical covariates (each one has different levels 3, 5, 2, and 4 ...
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0answers
140 views
Results from multinomial ordinal logistic regression model
I've an ordinal response variable (has 4 levels) and 3 categorical covariates (each one has different levels 3, 5, 2, and 4 respectively). We also are dealing with repeated observations. I fitted a ...
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votes
0answers
47 views
How do I get individual values of the random effect intercept in SPSS?
I am implementing a random intercept model in SPSS, and would like to obtain the subject-specific values of the random intercept to test it for normality. Does anyone know what's the SAS equivalent of ...
1
vote
0answers
82 views
SAS error: variance covariance matrix singular
I am now working with a classmate on an estimate of an Almost Ideal Demand System for tobacco consumption. We have chosen to make an AIDS regression using goods tobacco and alchol, and the CPI price ...
2
votes
1answer
158 views
Mixed model runs well in R whereas a random effect has only one level
How do you explain that ? There's only one operator but the mixed model returns an estimate for the operator random effect. Furthermore the ...
5
votes
4answers
476 views
Improving accuracy of a binary classification when the target is unbalanced
I am working on the BRFSS dataset with the goal of predicting Diabetes. The dataset has 500,000 rows and 405 columns. It is a 0/1 classification problem, the ratio of 0 to 1 is 90:10. I tried using ...
3
votes
0answers
186 views
How to specify in r spatial covariance structure similar to SAS sp(pow) in a marginal model?
I'm currently translating existing code from SAS to R. I'm working on longitudinal data (CD4 count over time). I have the following SAS code :
...
0
votes
0answers
46 views
Repeated measure problem (Discrete variables) [duplicate]
Possible Duplicate:
Difference between generalized linear models & generalized linear mixed models in SPSS
Repeated measure problem
I have 6 subjects. For each subject, we measured ...
0
votes
1answer
77 views
Repeated measure problem
I have 6 subjects. For each subject, we measured two variables over six-week period once a week. Let’s call the variables A and B. Variable A is binary (male or female), and variable B is continuous ...
0
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0answers
102 views
Interpretation of sas output of survival Frailty model using Proc NLMIXED
I am new to the site, I am trying to fit a Weibull gamma frailty model in SAS for multiple event times per subject, using proc nlmixed procedure. Please how do I ...
