In this case, it's mandatory that everyone in the subset be male after that, they can either be in-state students or at least juniors. The parentheses identify the "order of operations" in terms of how the conditional logic statement is read.
Notice that you can use multiple sets of parentheses to group conditional statements.
#DATA MERGE SAS DELETING RECORDS CODE#
The code required to make this subset is given below. Every subject included in the subset must be male, and in addition to being male, the subject must either a) be an in-state student, or b) be "at least a junior" - i.e., a junior or a senior. For example, how would we write the conditional logic for a subset containing only male students, and that live in-state or are at least juniors? In this case, there are three criteria variables: gender, state residency, and class rank. (Can you name what groups of students are included in this subset? Hint: there are four different groups.) Example - Extract cases matching a logical conditionĬonditional logic can get very complex, particularly when the criteria are based on multiple variables and/or multiple values. The resulting subset has 288 observations. To do this, we can use the DELETE keyword to remove observations where Rank = 1, which is the indicator value for freshman. Let's create a subset of the sample data that doesn't contain any freshmen students. Example - Delete cases with a specific value The inclusion or exclusion criteria appear after the IF statement. The "disqualifying" values you specify are called the exclusion criteria. DATA New-Dataset-Name (OPTIONS) Ĭreating a subset that contains only records without a certain value: In this case, your subset will be all of the cases that remain after dropping observations with "disqualifying" values. The criteria for keeping an observation is called the inclusion criteria. Inclusion and exclusion criteria are both statements of conditional logic that are based on one or more variables, and one or more values of those variables.Ĭreating a subset that contains only records with a certain value: In this case, your subset will keep the records that meet the criteria you specify. Subsets can be created using either inclusion or exclusion criteria.
#DATA MERGE SAS DELETING RECORDS HOW TO#
For instructions on how to drop or keep variables from a dataset, see our Data Step tutorial. Note: A related task is to select a subset of variables (columns) from a dataset. The difference between the two processes is in how the cases are selected. Both processes create new datasets by pulling information out of an existing dataset based on certain criteria. When splitting a dataset, you will have two or more datasets as a result.īoth subsetting and splitting are performed within a data step, and both make use of conditional logic. When subsetting a dataset, you will only have a single new dataset as a result.Ī split acts as a partition of a dataset: it separates the cases in a dataset into two or more new datasets. You can also think of this as "filtering" a dataset so that only some cases are included. In this tutorial, we use the following terms to refer to these two tasks:Ī subset is selection of cases taken from a dataset that match certain criteria. When preparing data for analysis, you may need to "filter out" cases (rows) from your dataset, or you may need to divide a dataset into separate pieces.
0 kommentar(er)
