What is it you are trying to accomplish here? AGGREGATE operates on an entire dataset while loop operates on the values in a case, so the two don't go together.

Hello Jon,

I want to run a block of syntax so many times, till a certain variable becomes sysmiss. In this block are some compute, aggregate and match files commands

something like this:

while (~sysmis(myvar)) insert "C:\temp\block.sps"

whether one can via Python do it?

thanks!

baiyun

Are you saying that you want to run this insert code if any case has a sysmis value for myvar or if all the values are sysmis or if a certain case has a sysmis value? The sysmis test will run on a per-case value, but you can't execute, say, an AGGREGATE command in the middle of passing the cases, since AGGREGATE works on the whole dataset.

yes, if any case has a sysmis value for myvar

at the beginning myvar has some valid value, after do block.sps many times, myvar becomes sysmis

i could do this with a macro, like

DEFINE !doit(loopnr = !cmdend)

!DO !cnt=1 !TO !loopnr

!repeat

!DOEND

!ENDDEFINE.

!doit loopnr = 3.

but i have to check output everytime, I want to do this automatically.

Here is an example of how you might do this. Annotations below.

compute z = $sysmis.
begin program.
import spss
while True:
curs = spss.Cursor([10])
values = curs.fetchall()
curs.close()
if not (None,) in values:
break
spss.Submit("""compute z = rv.uniform(0,1).""")
end program.

z is the 11th variable in this dataset. First it gets a cursor object and reads all the values for index 10 (zero based).
If any value is None, i.e., sysmis, it Submits some syntax, which could be an insert command, and repeats the process.

Since fetchall returns a tuple containing one element for each case because of the definition of this cursor, the test is whether a tuple with one element, i.e. (None,) , is in any of the cases.

HTH,

Jon

thanks Jon!

you wrote :

If any value is None, i.e., sysmis, it Submits some syntax

block.sps should run till myvar becomes sysmis completely

I ran

get file = "C:\temp\test.sav".

begin program.
import spss
while True:
curs = spss.Cursor([12])
values = curs.fetchall()
curs.close()
if not (None,) in values:
break
spss.Submit("INSERT FILE='c:/temp/block.sps'.")
end program.

spss runs non-stop?

That loop will run until there are no sysmis values. You might want to insert a DESCRIPTIVES command to see what is happening to the test variable, or just run the loop once and look in the DE.

I understand now why spss ran non-stop! what I want is the reverse direction!

i want: That loop will run until there are only sysmis values!

should I write if (None,) in values: instead if not (None,) ?

yes

Hello Jon

i let the following lines run:

get file = "C:\temp\test1.sav".

begin program.
import spss
while True:
curs = spss.Cursor([12])
values = curs.fetchall()
print values
curs.close()
if (None,) in values:
print 'ok1'

break

else:
print 'ok'
spss.Submit("INSERT FILE='c:/temp/block.sps'.")
end program.

in the output :

((12.85061,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,), (None,))

ok1

it is strange, ok didn't appear, although 12.85061 isn't a None

block.sps didn't be run too.