**Introduction to Important PROCs – FREQ, SUMMARY and FUNCTIONS in SAS**

- Proc Freq
- To determine the frequency of occurrence of values in categorical variables
- Results in frequency, cumulative frequency, percentage and cumulative percentage
- Can create a n-way crosstab using tables statement and * between the variables
- Crosstab results in frequency, percentage, row percent and column percent
- norow, nocol, nocumm, nopercent options can be used with Tables statement to customise the result

- Proc Summar
*y*- Similar to proc Means, used to extract basic statistics / summarize data
- Print or Output option MUST be used in Proc Summary to get the result
- By and Class statements can be used in Proc Summary

- Functions in SAS
- There are different types of functions in SAS, mainly used for data manipulation
- Text functions, Data Type conversion functions, Math / Stat functions, Date and Time functions
- Type conversion functions
- Input – to convert character data type to numeric
- Put – to convert numeric data type to character

- Text functions
- Substr – to extract part of a string, based on number of characters
- Scan – to extract part of a string, based on a delimiter