Some SPSS commands such as RECODE and ALTER TYPE can make irreversible changes to variables. Before using these, I like to clone the variables that I'm about to edit. This allows me to compare the edited to the original versions.
This tutorial presents a super easy tool for making exact clones of variables in SPSS. We'll use bank-clean.sav (partly shown below) for all examples.
Prerequisites & Installation
Installing this tool requires
- SPSS version 24 or higher with
- the SPSS Python 3 essentials installed.
Recent SPSS versions usually meet these requirements.
Download our tool from SPSS_TUTORIALS_CLONE_VARIABLES.spe. You can install it from as shown below.
After completing these steps, you'll find SPSS tutorials - Clone Variables under Transform.
Clone Variables Example I
Let's first clone jtype -short for job type- as illustrated below.
Completing these steps results in the SPSS syntax below. Let's run it.
SPSS_TUTORIALS_CLONE_VARIABLES VARIABLES=jtype
/OPTIONS FIX="c" FIXTYPE=PREFIX ACTION=RUN.
Result
Note that SPSS has now added a new variable to our data: cjtype as shown below.
Except for its name, cjtype is an exact clone of jtype: it has the same
- variable type and format;
- value labels;
- user missing values;
- and so on...
There's one minor issue with our first example: the syntax we just pasted only runs on SPSS installations with our tool installed.
The solution for this is to have the tool print native syntax instead: this syntax is typically (much) longer but it does run on any SPSS installation. Our second examples illustrates how to do just that.
Clone Variables Example II
Let's create native syntax for cloning a couple of different variables, including a string variable and a date variable.
This option has our tool print native syntax into our output window.
Because we chose to print (rather than run) syntax, this is one of the rare occasions at which we click Ok instead of Paste.
Result
Note that we now have native syntax for cloning several variables in our output window.
For actually running this syntax, we can simply copy-paste-run it in a syntax window.The entire syntax is shown below.
STRING clast_name (A30).
RECODE last_name (ELSE = COPY) INTO clast_name.
APPLY DICTIONARY FROM * /SOURCE VARIABLES = last_name /TARGET VARIABLES = clast_name.
RECODE gender (ELSE = COPY) INTO cgender.
APPLY DICTIONARY FROM * /SOURCE VARIABLES = gender /TARGET VARIABLES = cgender.
RECODE dob (ELSE = COPY) INTO cdob.
APPLY DICTIONARY FROM * /SOURCE VARIABLES = dob /TARGET VARIABLES = cdob.
RECODE educ (ELSE = COPY) INTO ceduc.
APPLY DICTIONARY FROM * /SOURCE VARIABLES = educ /TARGET VARIABLES = ceduc.
If our tool creates very long syntax, you could copy it into a separate file and run it from an INSERT command.
Right, I guess that should cover this simple but handy little tool. Hope you'll give it a try and hope you'll find it helpful. If you've any remarks, feel free to throw me a quick comment below.
Thanks for reading!
THIS TUTORIAL HAS 40 COMMENTS:
By Catherine on August 29th, 2016
Super! I didn't know the difference between these two types of variables. They were indeed string variables. I could therefore convert them into numeric variables and make the desired operations. Heel erg bedankt!
By Jon Peck on December 20th, 2017
Note that there are two other built-in tools with related functionality. APPLY DICTIONARY can copy selected metadata from one variable to another in the same or a different dataset. And the Visual Binner can collapse variables while generating appropriate metadata.
By Ruben Geert van den Berg on December 20th, 2017
Hi Jon!
The tool relies heavily on APPLY DICTIONARY. However, APPLY DICTIONARY can't copy-paste dictionary information from many to many variables in one dataset so the tool kinda speeds that up by spss.Submit-ting one command for each variable.
Also, if one or many string variables are entered, the tool throws in the required STRING commands with the right lengths.
So in short, whatever variable types/formats, the tool clones everything with a single line of syntax. I shouldn't say it but I really like this one myself actually.
By PATRICK KOOMSON on March 3rd, 2019
I have used SPSS for the past 16 years and had not heard of clone variables before. I recently faced a challenge of converting strings to numeric and luckily found this website. Its really cool. Thanks very much.
By Daniel on June 28th, 2019
That's a very useful Python Code. A few years ago I wrote the following SPSS Macro which basically does the same, but it can't handle the "TO" statement. And it uses a suffix instead of a prefix.
define !copy1to1 (suffix=!CHAREND('/') /source=!CMDEND)
!DO !var !IN (!source)
!concat("SHIFT VALUES VARIABLE=", !var, " RESULT=", !var, !suffix," SHIFT=0").
!DOEND
!DO !var !IN (!source)
!concat("APPLY DICTIONARY /FROM * /SOURCE VARIABLES =", !var, " /TARGET VARIABLES = ", !var, !suffix," /FILEINFO /VARINFO ALIGNMENT FORMATS LEVEL MISSING VALLABELS = REPLACE VARLABEL WIDTH").
!DOEND
!enddefine.
!copy1to1 suffix=_old /source=v1 v2 v3.