1) Explain what is SAS? What are the functions does it performs?
Ans: SAS means Statistical Analysis System, which is an integrated set of software products.
- Information retrieval and data management
• Writing reports and graphics
• Statistical analysis, econometrics and data mining
• Business planning, forecasting and decision support
• Operation research and Project management
• Quality Improvement
• Data Warehousing
• Application Development
2) Explain what is the basic structure of SAS programing?
Ans: The basic structure of SAS are
- Program Editor
• Explorer Window
• Log Window
3) What is the basic syntax style in SAS?
Ans: To run program successfully, and you have following basic elements:
- There should be a semi-colon at the end of every line
• A data statement that defines your data set
• Input statement
• There should be at least one space between each word or statement
• A run statement
For example: Infile ‘H: \StatHW\yourfilename.dat’;
4) Explain what is Data Step?
Ans: The Data step creates an SAS dataset which carries the data along with a “data dictionary.” The data dictionary holds the information about the variables and their properties.
5) Explain what is PDV?
Ans: The logical area in the memory is represented by PDV or Program Data Vector. At the time, SAS creates a database of one observation at a time. An input buffer is created at the time of compilation which holds a record from an external file. The PDV is created following the input buffer creation
6) Mention what are the data types does SAS contain?
Ans: The data types in SAS are Numeric and Character.
7) In SAS explain which statement does not perform automatic conversions in comparisons?
Ans: In SAS, the “where” statement does not perform automatic conversions in comparisons.
8) Explain how you can debug and test your SAS program?
Ans: You can debug and test your SAS program by using Obs=0 and systems options to trace the program execution in log
9) Mention what is the difference between nodupkey and nodup options?
Ans: The difference between the NODUP and NODUPKEY is that, NODUP compares all the variables in our dataset while NODUPKEY compares just the BY variables
10) Mention the validation tools used in SAS?
Ans: For DataSet : Data set name/ debug Data set: Name/stmtchk
For Macros: Options: mprint mlogic symbolgen