What does Nodupkey mean in SAS?

What does Nodupkey mean in SAS?

The NODUPKEY option removes duplicate observations where value of a variable listed in BY statement is repeated while NODUP option removes duplicate observations where values in all the variables are repeated (identical observations).

How do you delete duplicates in SAS data step?

The Sort Procedure with the NODUPKEY option is the simplest and most common way of removing duplicate values in SAS. Simply specify the NODUPKEY option in the PROC SORT statement. In the BY statement, specify the variables by which you want to remove duplicates.

How do you find duplicates in SAS?

When you use nodupkey and dupout in PROC SORT, you will remove the first of each set of duplicates in the output data set. That’s why each duplicated value has a frequency in dups that is one less than its frequency in test. To obtain ALL duplicates of a data set, you can take advantage of first. variable and last.

How does SAS Nodupkey work?

The NODUPKEY option checks for and eliminates observations with duplicate BY variable values. If an exact match using the BY variable values is found, the observation is not written to the output data set.

Does Nodupkey keep first record?

NODUPKEY writes only the first observation of each BY group to the new data set TOWNS. The BY statement specifies that observations should be ordered by town.

What is Dupout in SAS?

The DUPOUT= option is used with either the NODUPKEYS or NODUPRECS option to name a data set that will contain duplicate keys or duplicate observations. The DUPOUT= option is generally used when the data set is too large for visual inspection. In the next code example, the DUPOUT= and NODUPKEY options are specified.

What is the difference between Noduprecs and Nodupkey?

They work similarly in that they both can eliminate unwanted observations, but NODUPRECS compares all the variables in your data set while NODUPKEY compares just the BY variables.

How do you proc sort descending?

1. If you list just one variable, then SAS will sort the observations in the dataset based on ascending values of that variable.
2. You can sort in descending order by placing the keyword DESCENDING before the variable name that you want the dataset to be sorted on.
3. You can sort by as many variables as are in the dataset.

What does Noduprecs do in SAS?

PROC SORT’s NODUPRECS (or NODUPREC) (or NODUP) option identifies observations with identical values for all columns are removed from the output data set. The resulting output data saw the removal of the duplicate observations for Brave Heart and Rocky because they have identical data for all columns.

What is the difference between Nodup and Nodupkey?

The NODUP option in the SORT procedure eliminates observations that are exactly the same across all variables. The NODUPKEY option eliminates observations that are exactly the same across the BY variables.

What is Proc sort in SAS?

The SORT procedure orders SAS data set observations by the values of one or more character or numeric variables. The SORT procedure either replaces the original data set or creates a new data set. PROC SORT produces only an output data set. For more information, see Procedure Output.

How does the nodupkey work in Proc sort?

The NODUPKEY option in PROC SORT allows you to indicate that you would like records that repeat the key to be reduced down to one single observation. But SAS will randomly select one of the rows to keep. By following a PROC SORT with a DATA step, you can achieve a sorted data set, eliminate

What’s the difference between nodup and nodupkey in SAS?

Nodup. Though the Nodup also deals with duplicate observations, it does so in a different manner than the Nodupkey. While the Nodupkey considers only variabels in the By Statement, the Nodup Option considers entire observations. When Nodup is specified, the Sort Procedure compares the current observation to the previous observation.

How does nodup and nodupkey work in Excel?

The NODUPKEY option eliminates observations that are exactly the same across the BY variables. Keep in mind that both of these options compare adjacent observations in the output data set. Now that you know how the NODUP and NODUPKEY options work, you can use them in confidence to get the data set you want!

How does the proc sort in SAS work?

If you specify this option, PROC SORT compares all BY variable values for each observation to those for the previous observation written to the output data set. If an exact match using the BY variable values is found, the observation is not written to the output data set.