Sometimes you may have an option in a questionnaire which none of the respondents select. If you are using an Excel-style file or an SPSS file with incomplete code frames, the category will not appear when you create a table for the question. That is, if your variable is a scaled question 1-5 and no respondents selected 1, the Values for the variable in Displayr would be 2-5 and not show the 1 category. However, you may wish to have a table that includes the missing category with 0%.
You can add this missing category in a few ways:
Method 1 - Using a new R variable
Any will take you from a variable set with incomplete categories (shown in a table):
to one with the missing category included (Prefer not to answer below):
Requirements
- An Ordinal or Nominal variable set without negative category Values. This example uses the Gender variable from the cola example data set.
- For Method 3, you must have an Enterprise Displayr license and be familiar with How to Use QScripts in Displayr.
Method 1 - Using a new R variable
This is the most robust method for creating a new variable with the additional code. You call the original variable and manually set the order of the categories using the factor() function. Note that if a new category comes in for the original variable that is not listed in the hardcoded list of categories, it will appear blank in the data until it is added.
- In the Data Sources tree, select any variable and click + > Custom Code > R > Numeric.
-
Paste in the following code in the R Code editor and edit to your needs:
#get original variable
orig=Gender
#make vector of all the categories you want available including missing in the order you want
thecats=c("Male","Female","Prefer not to answer")
#do the conversion into categories
a=factor(orig,levels=thecats)
#click Calculate while Structure is numeric and then change to Nominal
- Click Calculate so the values are calculated when the variable is numeric.
- Then change Structure > Nominal to create the categories.
Method 2 - Using back coding
This method backcodes a dummy text variable into the original categorical variable and uses the Text Categorization module to add any missing categories. A couple of things to keep in mind:
- The values of the categories in the categorization tool must match the values of the categories in the original variable you are back-coding into. That is, the numbers next to the category in the tool must be what they were in the original variable.
- If you update the data later on and the missing option appears,
- If wanting to add a category into a variable set with a Binary - Multi or Nominal - Multi structure, see Additional details below.
To use this method:
- First, we'll create a fake text variable to use in the Text Categorization module. In the Data Sources tree, select any variable and click + > Custom Code > JavaScript > Text.
- Give it a Label like "dummy text".
- In the JavaScript Code editor box, simply type
NaNto create all missing values for the dummy text variable. - Click Calculate.
- With the dummy text variable selected, hover over the tree and select + > Text Categorization.
- Select Only one theme and click Start.
- The categorization tool will open.
- Click the Inputs and Back Coding button at the bottom.
- In the Corresponding back coding variables: field, select the variable you'd like to add the category to in the dropdown, such as Gender in our example:
- Click OK, and you will see the current gender categories added to the themes list on the left.
- Right-click and Add Theme.
- Give the new theme a name for the gender category you are missing and click OK.
- Repeat Steps 11-12 for as many categories as you are missing (note the number next to them in the list will be the underlying Value for that category in the new code frame).
- Click Save.
- You will now have a new variable with the missing categories added:
Additional details
When adding a category to a "-Multi" variable set using the back coding method, you cannot use a variable set with a - Multi structure directly in the process, so some additional steps are required. Before following the instructions above, first Split off one of the variables from the - Multi variable set and use that variable in the back-coding steps. Then, afterward, select that split-off variable and the larger variable set, then use Combine to add the back-coded variable to the larger variable set along with the new category.
Method 3 - Using a QScript
This method uses a QScript to add the value specified.
- Open the document with your data.
- Open the QScript editor through Tools
> QScript > New.
- Paste the below into the editor and look for ////EDIT for where to change the question name and add your new values:
includeWeb("QScript Utility Functions");
includeWeb("QScript Value Attributes Functions");
var data_file = project.dataFiles[0];
////EDIT Gender with your variable set label
var question = data_file.getQuestionByName("Gender");
var variable = question.variables[0];
// Create new copy of variable using JavaScript
var new_variable = data_file.newJavaScriptVariable(variable.name, false, preventDuplicateVariableName(data_file, variable.name), variable.label + " - Complete");
new_variable.question.questionType = "Pick One";
data_file.moveAfter([new_variable], variable);
// Copy existing values labels into new variable
copyValueAttributesForVariable(variable, new_variable);
// Add a new category by setting a label for a value that does not exist yet.
var value_attributes = new_variable.valueAttributes;
////EDIT change 3 to a new value for the new category
////change Prefer not to answer to your new category label
////to add more categories add additional copies of the line below
value_attributes.setLabel(3, "Prefer not to answer");
//OPTIONAL Show the results in a table
var new_table = project.report.appendTable();
new_table.primary = new_variable.question;
project.report.setSelectedRaw([new_table]);4. Press the Play button.
5. Click OK.
Your new "Gender - Complete" variable will now be found in the Data Sources tree.
Next
How to Modify Variables and Value Attributes via QScript
How to Add a Category for the Value Attributes Using the Displayr API