Sometimes, we prefer to sort variables manually with a custom sort order rather than alphabetically or Numerical sequence.
For example, we have a variable called ‘DelayCategory’. It contains three unique values such as ‘1-10 Minutes’, ’11+ Minutes’ and ‘No Delay’.
You want to reorder this chore list so that all the chores are grouped by DelayCategory, starting with No Delay followed by 1-10 Minutes and then 11+ Minutes. Simply using Proc Sort to sort by DelayCategory makes the list appear in Numerical Sequence followed by alphabetical sequence: 1-10 Minute, 11+ Minutes, No Delay.
For more information, see our guide on Default Sorting Order of Characters in SAS.
Method 1: Creating a custom sort order using Proc Format
The first solution is to create user-defined formats that map the DelayCategory to a number that represents the order in which the records will appear.
Download the example dataset from here.
proc format; value $delayfmt 'No Delay' = 1 '1-10 Minutes' = 2 '11+ Minutes' = 3; run;
The $delayfmt format is created to define the custom sort order.
BY variables in most SAS procedures including PROC SORT are sorted according to their internal values and not according to the formatted values.
In order, to use proc sort, we need an extra step to create the sort variable and use the new variable in Proc Sort By statement.
data flightdelays2; set flightdelays; neworder=put(delaycategory, delayfmt.); run; proc sort data=flightdelays2; by neworder; quit;
SAS offers alternatives to sort a dataset according to formatted values. You can use a proc SQL procedure to sort a dataset by formatted values. PROC SQL is similar to the data step and proc sort but is more powerful.
proc sql; select * from flightdelays order by put(delaycategory, $delayfmt.); quit;
Here, the put function is used to apply the manual sort order and ORDER BY is used to sort the variable. This yields a sorted data according to the formatted values.
Method 2: Creating a custom sort order using SQL Case when Statement
proc sql; select * from flightdelays order by case when delaycategory = 'No Delay' then 1 when delaycategory = '1-10 Minutes' then 2 when delaycategory = '11+ Minutes' then 3 end; quit;
This solution uses an in-line case when statements are used as an ORDER BY column. The CASE expression to map the delaycategory variable.
You can download this entire code from here.
So, this was our side of Creating a custom sort order in SAS. We really hope that you must have found it useful.
Moreover, if you have any other suggestions suggest them in the comment section.
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