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Data Step

Data <new name>; 

Retain <variables>; can be used to set the order of variables in the table (must come before the set statement)

Set <libref.file>; libref not required if the file is in the working library

Length <variable><$> W or <variable> w.d; where W=number of print places for character variable or for numerical W=bites and .d = decimal places

Assign new variables; type new variable name and then define

Label;

Format;

Where; create a data subset by limiting the table to a particular level of a variable

Drop <variables>; if the drop statement is used within set statement then variables are not read into the PDV (drop= ) and are thus not available for processing

Keep <variables>; limits the variables that are saved to the new dataset

If condition;

 run run; 

Multiple data sets an be created in one data step, which is best done with a select function:

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Otherwise; optional to otherwise output other

end;

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To avoid errors due to capitalisation, use the upcase or lowcase function, e.g., select (lowcase(<variable>))

To collapse levels of a variable, e.g, to collapse value 3 into 2

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if variable1=3 then variable2=2;

Converting character to numerical variables:

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<variable> = <variable> + 0

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Conditional Processing

If <argument>; restricts data set to the condition

Use else if for mutually exclusive statements (more efficient). Only 1 executable statement is allowed per IF-THEN statement; to perform multiple arguments then use IF-DO statement:

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Inclusive range for IF statement can be achieved with: 5 le <variable> le 7; gives observations between 5-7 inclusive

Numerical operators

Logical  operators

Modify where expressions: not / and / or

Eg where city not in('London','Rome','Paris') = city is not London, Rome or Paris

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Comparison operators

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Special where operators (can only be used for where statements)

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