Looping in SPSS to work through the cases - spss

I have a data set in SPSS containing a sequence of six variables from which I have to create a new variable which should contain the last value present in the sequence. Let's say the data look like this: (the second row contains all missing values but represents a case to which I'll merge some other variables later, so I need this too.)
DATA LIST /V1 TO V6 1-6.
BEGIN DATA
423451
73453
929
0257
END DATA.
Now if I wish to generate a variable named lastscr which should have values 1, ., 3, 9, 7. Can anyone help me on how should I do it in SPSS? I could not find any clue about it. Thank you in advance for any help.

This can easily be done with the DO REPEAT command:
DO REPEAT Var = V1 TO V6.
IF NOT(SYSMIS(Var)) lastscr = Var.
END REPEAT.

Related

We giving a task for Lua table but it is not working as expectable

Our task is create a table, and read values to the table using a loop. Print the values after the process is complete. - Create a table. - Read the number of values to be read to the table. - Read the values to the table using a loop. - Print the values in the table using another loop. for this we had written code as
local table = {}
for value in ipairs(table) do
io.read()
end
for value in ipairs(table) do
print(value)
end
not sure where we went wrong please help us. Our exception is
Input (stdin)
3
11
22
abc
Your Output (stdout)
~ no output ~
Expected Output
11
22
abc
Correct Code is
local table1 = {}
local x = io.read()
for line in io.lines() do
table.insert(table1, line)
end
for K, value in ipairs(table1) do
print(value)
end
Let's walk through this step-by-step.
Create a table.
Though the syntax is correct, table is a reserved pre-defined global name in Lua, and thus cannot should not be declared a variable name to avoid future issues. Instead, you'll need to want to use a different name. If you're insistent on using the word table, you'll have to distinguish it from the function global table. The easiest way to do this is change it to Table, as Lua is a case-sensitive language. Therefore, your table creation should look something like:
local Table = {}
Read values to the table using a loop.
Though Table is now established as a table, your for loop is only iterating through an empty table. It seems your goal is to iterate through the io.read() instead. But io.read() is probably not what you want here, though you can utilize a repeat loop if you wish to use io.read() via table.insert. However, repeat requires a condition that must be met for it to terminate, such as the length of the table reaching a certain amount (in your example, it would be until (#Table == 4)). Since this is a task you are given, I will not provide an example, but allow you to research this method and use it to your advantage.
Print the values after the process is complete.
You are on the right track with your printing loop. However, it must be noted that iterating through a table always returns two results, an index and a value. In your code, you would only return the index number, so your output would simply return:
1
2
3
4
If you are wanting the actual values, you'll need a placeholder for the index. Oftentimes, the placeholder for an unneeded variable in Lua is the underscore (_). Modify your for loop to account for the index, and you should be set.
Try modifying your code with the suggestions I've given and see if you can figure out how to achieve your end result.
Edited:
Thanks, Piglet, for corrections on the insight! I'd forgotten table itself wasn't a function, and wasn't reserved, but still bad form to use it as a variable name whether local or global. At least, it's how I was taught, but your comment is correct!

Replacing empty cells in a variable with values from another

I have a dataset with a number of columns. Two of them are practically the same however in variable column 1 there are string data that I would like to extract and replace in empty cells of variable column 2.
I tried using the syntax
If
variable_2 = "".
Compute variable_1 = variable_2.
End If
But do not get anything. Please, could someone help with this?
Much appreciated.
This should be either
if var2="" var2=var1.
(no period after the condition, no "end if")
OR
do if var2="".
compute var2=var1.
end if.
(this is a "do if" and not just an "if" - enables you to add commands after the condition, and not needed here).
In any case, if variable_2 is empty you want to run variable_2=variable_1 and not the reverse.

Syntax to add a new case to the data

If i have a variable in SPSS, with name (My_Variable), label (My Variable), values(1: Yes, 2: No) etc but without data (the column in data view is empty), i want to add data using syntax! For example, i want to add a participant in 1st row, who answered "Yes", so i want 1 to be added!!! How can i do it???
I found similar questions, but the solutions refers to creating A NEW SPSS window and add the values there! But i dont want this! I want to add data in an existing variable, without creating new SPSS file!
Apparently there is no way to directly add cases to an SPSS dataset through syntax.
But the following seems to me pretty close - you don't create new files but you create a new dataset and add it to your original.
Let's first create a small data to demonstrate on:
Data list list/ID (a5) var1 var2 var3 (3f2).
begin data
"first" 1 17 7
"secnd" 5 5 12
"third" 34 11 91
end data.
dataset name originalDataset.
So this is your original data. Now imaging that you want to add a new case to the data, with the ID value of "hello" and the number 42 in all the columns. This is what you do:
* creating the new case in a separate dataset.
Data list list/ID (a5) var1 var2 var3 (3f2).
begin data
"hello" 42 42 42
end data.
dataset name addition.
* going back to original dataset and adding the new case.
dataset activate originalDataset.
add files /file=* /file=addition.
exe.
dataset close addition.
You don't have to create data in the first data set. Just create the variables and define them however you want.
DATASET CLOSE ALL.
INPUT PROGRAM.
NUMERIC My_Variable (F1).
VARIABLE LABELS My_Variable "I want this!".
VALUE LABELS My_Variable 1 "Yes" 2 "No".
END FILE.
END INPUT PROGRAM.
DATASET NAME Empty.
DATA LIST FREE /My_Variable.
BEGIN DATA.
1 2
END DATA.
APPLY DICTIONARY /FROM Empty
/SOURCE VARIABLES=My_Variable
/TARGET VARIABLES=My_Variable
/VARINFO VALLABELS=REPLACE VARLABEL.
DATASET CLOSE Empty.
FREQUENCIES VARIABLES ALL.
I used DATASET but you could have save the empty file to disk.
See the APPLY DICTIONARY command for more details about how it works.
Using python you can add data with the cases.append() method
begin program.
import spss
spss.StartDataStep()
dataset = spss.Dataset()
dataset.cases.append([1])
spss.EndDataStep()
end program.
Say you have 3 variables, you can assign values to each by appending the list passed to the method
begin program.
spss.StartDataStep()
dataset = spss.Dataset()
dataset.cases.append([1,2,3])
spss.EndDataStep()
end program.
Would add a case wit value 1 in the first variable, value 2 in the second variable, 3 in the third variable.
Note: the method will only work within an open datastep.
Check out the ADD FILES command. You can also add cases with Python code.

How to read out a list of cases in one variable in SPSS and use that to add data?

To explain my problem I use this example data set:
SampleID Date Project Problem
03D00173 03-Dec-2010 1,00
03D00173 03-Dec-2010 1,00
03D00173 28-Sep-2009 YNTRAD
03D00173 28-Sep-2009 YNTRAD
Now, the problem is that I need to replace the text "YNTRAD" with "YNTRAD_PILOT" but only for the cases with Date = 28-Sep-2009.
This is example is part of a much larger database, with many more cases having Project=YNTRAD and Data=28-Sep-2009, so I can not simply select first all cases with 28-Sep-2009, then check which of these cases have Project=YNTRAD and then replace. Instead, what I need to do is:
Look at each case that has a 1,00 in Problem (these are problem
cases)
Then find the SampleID that corresponds with that sample
Then find all other cases with the same SampleID BUT WITH
Date=28-Sep-2009 (this is needed because only those samples are part
of a pilot study) and then replace YNTRAD in Project to
YNTRAD_PILOT.
I read a lot about:
LOOP
- DO REPEAT
- DO IF
but I don't know how to use these in solving this problem.
I first tried making a list containing only the sample ID's that need eventually to be changed (again, this is part of a much larger database).
STRING SampleID2 (A20).
IF (Problem=1) SampleID2=SampleID.
EXECUTE.
AGGREGATE
/OUTFILE=*
/BREAK=SampleID2
/n_SampleID2=N.
This gives a dataset with only the SampleID's for which a change should be made. However I don't know how to read out this dataset case by case and looking up each SampleID in the overall file with all the date and then change only those cases were Date = 28-Sep-2009.
It sounds like once we can identify the IDs that need to be changed we've done the tricky part here. We can use AGGREGATE with MODE=ADDVARIABLES to add a problem Id counter variable to our dataset. From there, it's as you'd expect.
* Add var IdProblemCnt to your database . Stores # of times a given Id had a record with Problem = 1.
AGGREGATE
/OUTFILE=* MODE=ADDVARIABLES
/BREAK=SampleId
/IdProblemCnt=CIN(Problem, 1, 1) .
EXE .
* once we've identified the "problem" Ids we can use `RECODE` Project var.
DO IF (IdProblemCnt>0 AND Date = DATE.MDY(9,28,2009) .
RECODE Project ('YNTRAD' = 'YNTRAD_PILOT') .
END IF .
EXE .

Print ResponseIDs of missing values SPSS

I'm creating a variable that will hold missing values from a specific variable. Currently, this works but it gives the missing a value a 1. How do I tell spss to print the respondent's ResponseID instead?
My code below:
COMPUTE Q_2_MIS = MISSING(Q_2).
EXECUTE.
Thanks
Your code returns value of 1 because the condition missing(q_2) is evaluated to TRUE.
Try this:
DO IF MISSING(Q_2).
COMPUTE Q_2_MIS = ResponseID .
END IF.
EXECUTE.
or (as per eli-k's comment) simply use IF:
IF MISSING(Q_2) Q_2_MIS = ResponseID .
EXECUTE.
Note that you might need to create the Q_2_MIS variable first, if you do not have it in your dataset.
Alternatively, if you want to print out the IDs of the respondents with missing in Q_2:
TEMPORARY.
SELECT IF missing(q_2).
LIST ResponseID q_2.
You will see a list of IDs in the SPSS Output, with a (blank) Q_2 next to each ID.

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