Can’t find your question? Try checking our General FAQ page.

**Installing, Customizing, Updating, Renewing**

- See the pages on Installing, Customizing,Updating, Renewing for help with these topics.
- How do I update my SAS setinit (when my SAS has not yet expired)?
- How do I update my SAS setinit when my SAS/Windows has expired?

## Reading/Writing Files

**Converting among SAS, SPSS and Stata Data Files**

**Reading & writing data files**

- How do I read a data file that uses commas, tabs or spaces as delimiters between variables?
- How do I write a data file that uses commas, tabs or spaces as delimiters between variables?
- How do I read a delimited file with missing values?
- How do I read a delimited file that has delimiters embedded in the data?
- What are some common infile options for reading a raw data file?
- How do I read raw data files compressed with gzip (.gz files) in SAS?
- How do I read raw data via FTP in SAS?
- How can I read multiple raw data files in SAS?
- How do I read/write Excel files with .xls extensions in SAS?
- How do I create an ASCII file from a sas data set using put statement?
- How do I read multiple raw data files with the same structure in one data step?
- How do I read in a character variable with varying length in a space delimited dataset?
- How do I write out a fixed-format file in SAS?

**Transferring Files to & from other computer platforms**

**Reading/Writing SAS files with formats**

## Data Management

**General data management tasks**

- How do I use keep and drop efficiently?
- How do I check that the same data input by two people are consistently entered?
- How do I create a format out of a string variable?
- How do I display information for all the SAS datasets in a directory?
- How do I make unique anonymous ID variables for my data?
- How do I standardize variables (make them have a mean of 0 and sd of 1)?
- Is there a quick way to create dummy variables?
- How to access and use SAS ZIPCODE data files for the United States?
- How can I recode my ID variable to be short and numeric?
- Where can I find more functions to create new variables?
- How can I reshape pairs data long to wide?

**Date and time related**

**Manipulating string variables**

**Missing data issues**

**Multilevel data issues**

## Statistics

**Analysis of variance**: when predictors are categorical

- How can I do test of simple main effects?
- How can I do ANOVA contrasts?
- How can I perform a repeated measures ANOVA with proc mixed?
- How can I minimize loss of data due to missing observations in a repeated measures ANOVA?
- How can I test contrasts and interaction contrasts using the estimate statement?

**Linear regression**: for continuous or normally distributed variables

- How do I interpret the parameter estimates for dummy variables in proc reg or proc glm?
- How can I compare regression coefficients between two groups?
- How can I compare regression coefficients across three (or more) groups?
- How can I test differences in means using a cell means model?
- How can I compute omega squared in SAS after proc glm?
- Why are Type III p-values different from the estimate p-values in proc glm?

**Logistic regression**: for binary or dichotomous outcomes

- How do I interpret odds ratios in logistic regression?
- Why are my logistic results reversed?
- How do I do a conditional logit model analysis in SAS?
- How to estimate relative risk in SAS using proc genmod for common outcomes in cohort studies?
- In Proc Logistic why aren’t the coefficients consistent with the odds ratios?
- How can I get “adjusted” predicted values from a logistic model in SAS?
- How can I create contrasts with proc logistic?

**Multilevel**: for hierarchical or non
independent data

**Spatial statistics**

**Survival analysis**

**Survey**: for modeling complex surveys and
using weights

- What types of weights do SAS, Stata and SPSS support?
- Sample setups for commonly used survey data sets
- Choosing the correct analysis for various survey designs, including
- How can I take a simple random sample with or without replacement using proc surveyselect?
- How can I take a stratified random sample using proc surveyselect?

**Multiple imputation**: for missing data

**Other statistics**

- Simple linear and nonlinear models using nlmixed.
- From an OLS model to full mixed models using proc nlmixed.
- How can I do zero-truncated count models using nlmixed?
- Using the predict statement with nlmixed for predictions based on fixed and random effects.
- How can I do path analysis in SAS?
- Kappa statistic for variables with unequal ranges of scores
- How can I compute Mahalanobis distance?
- How can I obtain percentiles not automatically calculated?
- How can I compute Durbin-Watson statistic and 1st order autocorrelation in time series data?
- How do I compute tetrachoric correlations in SAS?
- How can I perform a bivariate probit analysis using proc olim in SAS 9.1?
- How do I test on Pearson correlation using Fisher’s Z transformation in SAS 9.x?
- How Do I perform Chow test in SAS using proc autoreg?
- How can I test for equality of distribution?
- How can I bootstrap estimates in SAS?
- How can I generate a dose response curve in SAS?

## Graphics

**Graphics**

- How can I graph two (or more) groups using different symbols?
- What are some of the different symbols that I can use on a scatter plot?
- How can I move text on a plot?
- How can I use the SAS output delivery system?
- How do I make a histogram with percentage on top of each bar?
- How can I visualize longitudinal data in SAS?
- How can I generate maps in SAS using an external shape file?
- How can I overlay density plots of different variables by group in SAS?

## Other

**Macro Variables and Macro Programs**

**Output**

- How can I create tables using proc tabulate?
- How can I change the way variables are displayed in proc freq?
- How can I export my SAS results to an Excel spreadsheet?
- How can I send SAS data/results to specific cells in an Excel spreadsheet?
- How can I include cells with zero counts in proc freq with the list option?
- How can I generate pdf and html files for my SAS output?