6781097196

other character functions can be useful in determining where to start sub stringing.

Some examples -

• The last three characters of a variable are an id that requires a new variable. An additional hurdle is that the variable length is not constant.

To extract the last 3 characters in this case the LENGTH function is used to define the starting position.

Data cleandata;

Set dirtydata;

a = substr(oldid,length(oldid)-3); put a;

Oldid_New    Id

A123B24    B24

AS1456B35    B35

A character or a specific set ot characters occur where the character string starts. Using the data from the last example, the last 3 characters can be extracted using INDEX to define the starting position.

data cleandata; set dirtydata; oldidx = upcase(oldid); a = substr(oldid,index(oldidx,’B'),3);

In this case, the length of the character string to be extracted was specified. Notę - case is important here so the following variation removes any case problems without affecting the case of the extracted string.

Date/Time Functions

Date/Time functions are a set of functions that return portions of datę time, datę, or time values or convert numeric values for month, day and year or hour, minutę and seconds into SAS datę or time values. These functions are especially useful for extracting the datę and time from a datę time value or converting separate month, day and year values into a SAS datę value.

The following is a list of date/time functions that are extremely useful in data cleansing.

For example -

The new mailing list has in one case separate yariables for month, day, and year for one datę. The problem is that this data needs to be added to a pre-existing data set that contains this information as a single SAS datę. If the data is numeric, then the use of the MDY function converts the separate variables into a single datę value variable. However, if the data is character then the conversion to numeric should occur first and then the conversion to the

The following codes shows how this two(2) part process can occur within one (1) statement.

data newlist;

set newdata.maillist;

newdate=mdy(input(mon,2.), input(day,2.), input(yr,4.);

run;

Notę: as noted before if the character variables are not converted to numeric before the use in the MDY function, SAS will automatically convert these values to numeric and issue a warning at the end of the DATA step. However, good programming practices prefer the conversion of character yariables into numeric before their use in a function like MDY.

“Geographic” Functions

“Geographic" functions consist of a set of State and zip codę functions that can be used to verify State name spelling and State abbreviations (to a point). Ali useful when data cleansing, especially the conversion of the zip codę to the abbreviation. This

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