REPLACE Statement |
The REPLACE statement replaces values of observations in a SAS data set.
The arguments to the REPLACE statement are as follows:
specifies a range of observations.
selects a set of variables.
is evaluated for being true or false.
The REPLACE statement replaces the values of observations in a SAS data set with current values of matrices with the same name. Use the range, VAR, and WHERE arguments to limit replacement to specific variables and observations. Replacement matrices should be the same type as the data set variables. The REPLACE statement uses matrix elements in row order replacing the value in the th observation with the th matrix element. If there are more observations in range than matrix elements, the REPLACE statement continues to use the last matrix element.
For example, the following statements cause all occurrences of 'ILL' to be replaced by 'IL' for the variable STATE:
state="IL"; replace all var{state} where(state="ILL");
You can use any of the following keywords to specify a range of observations:
all observations
the current observation
the next observation or the next number of observations
all observations after the current one
observations by number, where value can be one of the following:
Value |
Example |
---|---|
a single record number |
point 5 |
a literal that contains several |
point {2 5 10} |
record numbers |
|
the name of a matrix |
point p |
that contains record numbers |
|
an expression in parentheses |
point (p+1) |
If the current data set has an index in use (see the INDEX statement, the POINT option is invalid.
You can specify a set of variables to use with the VAR clause. The variables argument can have the following values:
a literal that contains variable names
the name of a matrix that contains variable names
an expression in parentheses that yields variable names
one of the keywords described in the following list:
for all variables
for all character variables
for all numeric variables
The following examples demonstrate each possible way you can use the VAR clause.
var {x1 x5 x9}; /* a literal matrix of names */ var x; /* a matrix that contains the names */ var("x1":"x9"); /* an expression */ var _all_; /* a keyword */
The WHERE clause conditionally selects observations, within the range specification, according to conditions given in the clause. The general form of the WHERE clause is
The arguments to the WHERE clause are as follows:
is a variable in the SAS data set.
is any one of the following comparison operators:
less than
less than or equal to
equal to
greater than
greater than or equal to
not equal to
contains a given string
does not contain a given string
begins with a given string
sounds like or is spelled like a given string
is a literal value, a matrix name, or an expression in parentheses.
WHERE comparison arguments can be matrices. For the following operators, the WHERE clause succeeds if all the elements in the matrix satisfy the condition:
= ? < <= > >= |
For the following operators, the WHERE clause succeeds if any of the elements in the matrix satisfy the condition:
= ? =: =* |
Logical expressions can be specified within the WHERE clause by using the AND (&) and OR (|) operators. The general form is
clause & clause |
(for an AND clause) |
|
clause | clause |
(for an OR clause) |
where clause can be a comparison, a parenthesized clause, or a logical expression clause that is evaluated by using operator precedence.
Note: The expression on the left-hand side refers to values of the data set variables, and the expression on the right-hand side refers to matrix values.
The following statement replaces all variables in the current observation:
replace;