How Does Your Data Compare? Differences in record count - patient selection and count, visits and dates. Differences in variable count - missing variables. Differences in data values - data values. You can use this procedure also to compare two variables from the same dataset.
The syntax of this procedure is very simple and easy to remember. For this purpose, we create two datasets work. As base dataset we use work. The comparison dataset is work. In other words, it compares the values in the first row of the base dataset with the values in the first row of the comparison dataset. Then, it compares the values of the second row in both datasets, etc. Later we will discuss how to specify matching observations.
The Data Set Summary shows you which two datasets were taken into account and compares their meta-data. It summarizes the moment when the datasets were created and modified, the number of variables, the number of observations, and the dataset labels.
It shows you that the number of variables NVar is the same, but that the number of observations NObs and the labels are different. Do you know? The Variables Summary provides information about the differences in the variables of the compared datasets.
It compares the variables and their attributes i. The image above shows the Variables Summary of the comparison between work. It summarizes that both datasets have two variables in common namely, FirstName and LastName , as well as one unique variable Age and Salary.
The summary also shows that there are two common variables with different attributes. The Listing of Common Variables with Differing Attributes contains the differences in Length, Label, and Format of variables that are present in both datasets. The image above shows that the variables FirstName and LastName have different attributes. In the work. Data Sets. These datasets contain a list of customers, their unique customer IDs, first names, last names and middle initials. Basic Comparison of Two Datasets.
After running the above code, you will notice the Results are divided into 5 summaries. Limiting the Comparison to Certain variables. In many cases when you are comparing two datasets, there will be a common ID variable or multiple ID variables between the two datasets. If both datasets have a unique ID number you can merge the files together and conduct a more in-depth record level comparison.
Although we are comparing the same two datasets as in the first example, the results are much different now with the ID option included. When the NAME variable is used with the ID option, the Observation Summary now indicates that of the 19 observations in each dataset, all 19 ID values are common between the 2 datasets. Furthermore, for those common variables, there are no unequal values in any variable now that we have matched the datasets on NAME:.
Comparing Metadata Dataset Attributes. Now, the output will be expanded to list all the variables in one dataset but not the other, and vice versa:. Do you have a hard time learning SAS? Start Course for Free! Comparing Datasets by Observations. If for example you wanted to examine how many times the predicted value was different from the actual value, the largest difference between values as well as the specific differences and percentage differences between the two you can use a single call to PROC COMPARE.
The syntax for within dataset comparisons is quite simple. Next, you use the VAR statement to list any variables you want to compare. After specifying the variables you want to compare, the WITH statement is used to specify the corresponding variables you want to compare the first set of variables with. Comparing Specific Values in an Output Dataset. It is often convenient to the SAS Data Scientist to compare data sets and check if two data sets are identical.
The procedure compares two data sets and provides information on possibles differences between them. It also lets you check if two data sets are exactly identical, which is important if you move data sets between servers or libraries and want to keep exact copies of your production data sets. This example page demonstrates how to check if two data sets are exactly identical.
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