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Re: st: tostring for large double type variables?


From   Nick Cox <njcoxstata@gmail.com>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: tostring for large double type variables?
Date   Tue, 9 Aug 2011 07:00:01 +0100

That is very clear.

You are going to want to process these individually, so why not read
them in as 45 distinct numeric variables?

On Mon, Aug 8, 2011 at 7:44 PM, Paul Burkander <paul@burkander.com> wrote:
> yes, the numbers are just identifiers.  Specifically, they are the
> concatenated answers from a multiple choice test.  The test might have
> about 45 questions for a given subject, and the answers are 1-5, for
> instance.
>
> We receive new files each year with updated test results.  The format
> for the files changes quite frequently.  I'm trying my best to come up
> with a general system that will append all the files as future files
> arrive.  I'm striving to avoid requiring specific coding for specific
> problems.  I carefully categorize variables based on whether they can
> be easily set to the same type.  For those that can't be, I do a force
> destring, but then I lose some information.  I thought it would be
> useful to set up an alternative process where instead I change the
> "problem" variables to strings, but unfortunately I've run into this
> problem.  Ultimately I'd like a general method of reconciling all
> variable types across data sets that doesn't require a case-by-case
> approach.
>
> Let me know if more clarification would be useful.
>
> Paul
>
> On Mon, Aug 8, 2011 at 12:47 PM, Nick Cox <njcoxstata@gmail.com> wrote:
>> As its original author, I am not clear that this is a good use of
>> -tostring-, but its -format()- option offers in principle what you
>> seek.
>>
>> You might get better advice if you said more about the data and quite
>> how this strange situation occurs. The bottom line is that what you
>> intend to do with the variable should have most influence on how it is stored.
>>
>> At the moment I'm having real difficulty imagining a measurement
>> process that yields 45 digits. Is there a decimal point? Are these
>> "numbers" just identifiers of some kind?
>>
>> Nick
>>
>> On Mon, Aug 8, 2011 at 4:11 PM, Paul Burkander <paul@burkander.com> wrote:
>>>  I'm appending files over multiple years where the variable type
>>> changes over time.  I have a variable that's a long string of numbers
>>> (about 45 numbers) in some years, but which is stored as double in
>>> other years.  I'd like to be able to store the variable as either a
>>> string or double in the appended file, but I can't figure out a way to
>>> use the tostring command that doesn't truncate the double variable.
>>>
>>>  Is there an easy way to preserve the information and string the variable?
>>

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