Question-: What is the use of automatic variable generated in the Data step?
Answer: There are two automatic variables generated in the Data step which are as below, this both variables has initial value set as missing. As on when Data step process each step they are updated accordingly - _N_ : It represents how many time DATA step has been iterated. - _ERROR_ : It has binary value either 0 or 1 , if while processing the records if there is any error then this would be set as 1 else remain 0. Both of this variable are not printed as output, once the DATA step completed.
Question-: Can SAS proc process the RAW data directly?
Answer: Generally, not, your RAW data first needs to be converted into SAS Dataset then SAS proc can process this SAS Dataset.
Question-: What all are the possible ways to tell the SAS for reading data?
Answer: There are mainly three input styles in the SAS - List input: This style is used when each field in the raw data is separated by at least one space and field value does not have embedded space in it. You have to provide the list of the variable names. - Column Input: In this case each column has fixed width. - Formatted input: In this case you have to specify the format of the data. For instance, numeric data can contain special symbol.
Question-: What is informats?
Answer: While using Formatted input read style you have to provide specific instructions about the format of the data. These instructions are known as informats. For example what is the format of the date.