The Automatic Recode dialog box allows you to convert string and numeric values into consecutive integers. When category codes are not sequential, the resulting empty cells reduce performance and increase memory requirements for many procedures. Additionally, some procedures cannot use string variables, and some require consecutive integer values for factor levels.
- The new variable(s) created by Automatic Recode retain any defined variable and value labels from the old variable. For any values without a defined value label, the original value is used as the label for the recoded value. A table displays the old and new values and value labels.
- String values are recoded in alphabetical order, with uppercase letters preceding their lowercase counterparts.
- Missing values are recoded into missing values higher than any nonmissing values, with their order preserved. For example, if the original variable has 10 nonmissing values, the lowest missing value would be recoded to 11, and the value 11 would be a missing value for the new variable.
Use the same recoding scheme for all variables. This option allows you to apply a single autorecoding scheme to all the selected variables, yielding a consistent coding scheme for all the new variables.
If you select this option, the following rules and limitations apply:
- All variables must be of the same type (numeric or string).
- All observed values for all selected variables are used to create a sorted order of values to recode into sequential integers.
- User-missing values for the new variables are based on the first variable in the list with defined user-missing values. All other values from other original variables, except for system-missing, are treated as valid.
Treat blank string values as user-missing. For string variables, blank or null values are not treated as system-missing. This option will autorecode blank strings into a user-missing value higher than the highest nonmissing value.
You can save the autorecoding scheme in a template file and then apply it to other variables and other data files.
For example, you may have a large number of alphanumeric product codes that you autorecode into integers every month, but some months new product codes are added that change the original autorecoding scheme. If you save the original scheme in a template and then apply it to the new data that contain the new set of codes, any new codes encountered in the data are autorecoded into values higher than the last value in the template, preserving the original autorecode scheme of the original product codes.
Save template as. Saves the autorecode scheme for the selected variables in an external template file.
- The template contains information that maps the original nonmissing values to the recoded values.
- Only information for nonmissing values is saved in the template. User-missing value information is not retained.
- If you have selected multiple variables for recoding but you have not selected to use the same autorecoding scheme for all variables or you are not applying an existing template as part of the autorecoding, the template will be based on the first variable in the list.
- If you have selected multiple variables for recoding and you have also selected Use the same recoding scheme for all variables and/or you have selected Apply template, then the template will contain the combined autorecoding scheme for all variables.
Apply template from. Applies a previously saved autorecode template to variables selected for recoding, appending any additional values found in the variables to the end of the scheme and preserving the relationship between the original and autorecoded values stored in the saved scheme.
- All variables selected for recoding must be the same type (numeric or string), and that type must match the type defined in the template.
- Templates do not contain any information on user-missing values. User-missing values for the target variables are based on the first variable in the original variable list with defined user-missing values. All other values from other original variables, except for system-missing, are treated as valid.
- Value mappings from the template are applied first. All remaining values are recoded into values higher than the last value in the template, with user-missing values (based on the first variable in the list with defined user-missing values) recoded into values higher than the last valid value.
- If you have selected multiple variables for autorecoding, the template is applied first, followed by a common, combined autorecoding for all additional values found in the selected variables, resulting in a single, common autorecoding scheme for all selected variables.
To Recode String or Numeric Values into Consecutive Integers
- From the menus
- Select one or more variables to recode.
- For each selected variable, enter a name for the new variable and click New Name.