How To Find The Number Of Observations In A Dataset

Video How to find the number of observations in a dataset The SAS dataset consists of a descriptor part and a data part containing data values. The descriptor portion of the SAS dataset holds detailed information about the dataset. This information includes:

Dataset name and its ember type
Data set creation time
The number of observations
Number of variables
Engine type

Most of us need to count the number of observations in the SAS dataset and pass it to a macro variable. Reading the descriptor is one of the most efficient and fastest ways to determine the number of observations in a SAS dataset. Read: how to find the number of observations in a dataset In this post, we will see different methods to count the number of rows (records) in a SAS dataset.

1. Using PROC SQL

Contents

Using the PROC SQL method is not considered an efficient way because it does not use the metadata information of the SAS dataset. Instead, it reads through each record (row) of your SAS dataset, which requires processing power. However, it is simple to understand and develop and can be used for smaller datasets.

2. Use END = Statement

This method is also ineffective. It reads the entire dataset and increments a counter to get the last value of the dataset. The END option returns true or 1 if the observation is the last observation in the data set.

3. Using the Data Step

NOBS . macros.

4. Use IF 0 and STOP . statements

During the compile phase, the data step reads in the variables from the data set in the Set Statement. During execution, SAS reads observations from the input dataset in sequential order. By using if 0 then set we can skip execution part of Set Statement which is conditional logic always failThe ‘if 0’ statement is not processed at all because the IF statement does not hold TRUE. The entire IF-THEN statement is used to pull the header information of the dataset and then pass it to the compiler to adapt it to PDV.If 0 then Set can also be encoded as If (1 = 2) then SetThe STOP statement is used to stop an endless loop. Read – Exploring the SET statement in SAS

5. SQL Proc Dictionary Method

The dataset metadata information that can be accessed with PROC SQL topqa.info is an efficient method because it does not look at each dataset’s value to determine the count. Read more: How to calculate spot rate for load name of library in which data is stored. MEMNAME = reference to a SAS table (data set). Delimited by ” in this case is used to left-align the numeric value.

6. Using the Library panel – topqa.infoLE

As we know that SAS library tables contain metadata related to your dataset and we can get this information from topqa.infoLE by specifying LIBNAME and the name of the dataset. The two variables you need from the table are Nobs which contains the total number of observations including those marked for deletion and Delobs which contains only the number of observations marked for deletion. in a SAS dataset has advantages over the previous methods described so far. That is if you (or someone else) is modifying the dataset, you need to know the total number of observations in the dataset as well as the number of observations that have been marked for deletion (but still counted when you use NOBS = optional). select SET).

7. Using automatic variables PROC SQL – SQLOBS

Proc SQL automatically creates the SALOBS macro variable, when it runs an SQL Step. The SQLOBS macro variable will have the observable count of the last SQL proc statement executed.