Variables 1
Defining - done in the Input Statement sets attributes name type length informat (if any) format (if any) label (if any)
the default is numeric and length is 8 bytes (the length of numerical variables is not affected by informats or column specifications, but can be increased to something similar to double precision -- we will discuss this later Following the variable name with a $ changes the type of the variable to a character variable of length of 8 bytes for list input. You can push this to 200 characters by using either input name $ 1-200; or input name $200.;
We will talk about the "format" and "label" attributes at the end of the lecture.
2 1Line
# 1 of input records: pointer
input buffer column #1 the input statement brings data to the input buffer & gives you control over how to move the data from the buffer to the data vector via "the data pointer" Things that affect your choice of input style (see Chapter 2 of your text). -- How the data is entered on the records (cards, etc.)? ------How you would like to enter the data? Do character variables have imbedded blanks? Do numeric variables contain non-numeric character? ($ , % ) Do the data contain time or date values that require special instructions? Is there more than one observation per input record? Is the data for a single observation spread over several input records?
3
Input type:
LIST
Restrictions: -- must have data values separated by blanks -- data fields must be in same order as variables list in the input statement -- missing values are represented by a "." for numeric variables and must be present. -- character variables can't have embedded blanks -- default length for character variables is 8 bytes (longer values are truncated when SAS writes to the program data vector; you can change this with the LENGTH statement and still use LIST input. -- Must have data in standard character or numeric form (i.e. no $ , % in numeric etc.) List input requires the fewest specifications in the INPUT statement. However, you can not input all data sets with LIST therefore, input; we must learn other styles. Pointer Movement -Input idno name $ team $ strtwght endwght; cards; 1023 David Red 189 165 ; (See Program SAS_Lec#2_input_01.sas)
the pointer is left in the column immediately following the last read column.
4
Input type:
COLUMN INPUT
Data values occupy the same fields within each record. You specify these column locations in the INPUT statement. --------data must be standard character or numeric form when using column input, your aren't required to indicate missing values with a placeholder such as a period uses the columns specified to determine length of character input variables unlike LIST, it reads data until it reached the end of the last specified column, not until it reaches a blank can skip columns altogether read columns in any order can read only a part of a value or reread the value character variables can be up to 200 characters in length
(See Program SAS_Lec#2_input_02.sas) Input type: FORMATTED INPUT
Data can be stored in special formats such as binary, packed decimal, special formats (time & dates), or imbedded commas and monetary symbols. So we need ways to input this data. You must use SAS's pre-programmed formats. (See Program SAS_Lec#2_input_03.sas)
5
You can mix formatt...