How to Use MONOTONIC Function in SAS (With Examples)

You can use the MONOTONIC() function in SAS to generate row numbers for a dataset.

Here are two common ways to use this function in practice:

Method 1: Use MONOTONIC() to Create Column of Row Numbers

/*create column called row_ID that contains row numbers*/
proc sql;
    select team, monotonic() as row_ID
    from my_data;
quit;

Method 2: Use MONOTONIC() to Filter Dataset by Row Numbers

/*filter where row number is less than 5*/
proc sql;
    select *
    from my_data
    where monotonic() < 5;
quit;

The following examples show how to use each method in practice with the following dataset in SAS:

/*create dataset*/
data my_data;
    input team $ points assists;
    datalines;
Cavs 12 5
Cavs 14 7
Warriors 15 9
Hawks 18 9
Mavs 31 7
Mavs 32 5
Mavs 35 3
Celtics 36 9
Celtics 40 7
;
run;

/*view dataset*/
proc print data=my_data;

Example 1: Use MONOTONIC() to Create Column of Row Numbers

The following code shows how to use the MONOTONIC() function to create a new column called row_ID that contains the row number (starting from 1) for each observation in the dataset:

/*create column called row_ID that contains row numbers*/
proc sql;
    select team, monotonic() as row_ID
    from my_data;
quit;

Notice that a new column has been created called row_ID that contains the row number for each observation in the dataset, ranging from 1 to 9.

Example 2: Use MONOTONIC() to Filter Dataset by Row Numbers

The following code shows how to use the MONOTONIC() function to filter a dataset where the row number is less than 5:

/*filter where row number is less than 5*/
proc sql;
    select *
    from my_data
    where monotonic() < 5;
quit;

Notice that only the first four rows from the dataset are shown since we used the MONOTONIC() function to specify that the row number must be less than 5.