Re: st: extracting of data

[Prakash Singh <prakashbhu@gmail.com>]

Nick first of all I should tell you I am not use to with programming,
what I have written is through reading the stata post and using my
small capability, so there is huge chances of error for that reason I
seek help.

Now, I would try to explain you the logic of my code and loop.
As you know the raw data is structured so that I need to extract 81
(9*9) data files and then append set of 9 files into one. This takes
lot of space in the system, so I thought of writing code where I can
extract the data but finally I should have only appended data files.
I just wanted to get rid off 81 data file space consumption.

One more bit of information, it seems that the code I have written is
only reading the first dct file.

I hope this will help you to understand and help me come out of this.
I tried to work out the suggestion of Daniel and yours but I failed. I
am still trying to work it out.

Regards
Prakash

On Tue, Jan 22, 2013 at 12:00 AM, Nick Cox <njcoxstata@gmail.com> wrote:
> You are resurrecting a thread from January 1, but your code raises
> questions very similar to those in a thread you started today,
> principally that
>
> 1. The logic of your loop is hard to follow.
>
> 2. Using -capture- prevents you (and us) from seeing error messages
> that might be informative.
>
> As I understand it, you have 9 files for levels 1...9 and within your loop you
>
>          infile using D:\TEAM_PC\level`l'\level`l'.dct, clear
>          capture append using `mydata'
>          save `mydata', replace
>          keep if level==`l'
>          save "D:\TEAM_PC\level`l'_list.dta", replace
>
> However, whatever the -append- and -save- do is cancelled out by the
> -keep-, so you might as well go
>
>          infile using D:\TEAM_PC\level`l'\level`l'.dct, clear
>          save "D:\TEAM_PC\level`l'_list.dta"
>
> So that will give you 9 files and you can -append- them in one
> command; no loop is needed. See the on-line help for -append-
>
> http://www.stata.com/help.cgi?append
>
> (If your Stata version does not support this multiple file syntax,
> then as advised in the FAQ you should be telling us what version you
> have.)
>
> I can't tell you what is going on with your `mydata'. As Daniel
> pointed out earlier today, it is unclear why you are using a temporary
> file here, but that's another detail.
>
> Nick
>
> On Mon, Jan 21, 2013 at 6:15 PM, Prakash Singh <prakashbhu@gmail.com> wrote:
>> Nick
>> Though I managed to write the code and run it but I realised today
>> that for each level stata is extracting data from only one txt file.
>> which means that only one dct file is being read.
>>
>> here is the revised code
>>
>> clear
>> set more off
>> set mem 500m
>> tempfile mydata
>> forv l=1/9 {
>>         infile using D:\TEAM_PC\level`l'\level`l'.dct, clear
>>         capture append using `mydata'
>>         save `mydata', replace
>>         keep if level==`l'
>>         save "D:\TEAM_PC\level`l'_list.dta", replace
>> }
>>
>>
>> Regards
>> Prakash
>>
>> On Tue, Jan 1, 2013 at 9:32 PM, Prakash Singh <prakashbhu@gmail.com> wrote:
>>> Thanks Nick
>>> I got it finally
>>>
>>> Best wishes to all stata listers for 2013
>>>
>>> Regards
>>> Prakash
>>>
>>> On Mon, Dec 31, 2012 at 11:10 PM, Nick Cox <njcoxstata@gmail.com> wrote:
>>>> I don't understand what is holding you up. Your code shows that you
>>>> are familiar with -foreach- and -forval-. So you need to write another
>>>> big loop using that construct.
>>>>
>>>> Nick
>>>>
>>>> On Mon, Dec 31, 2012 at 4:37 PM, Prakash Singh <prakashbhu@gmail.com> wrote:
>>>>> Nick, I thanked you for that
>>>>>
>>>>> I mentioned in the first mail that the structure of the data is such
>>>>> that to have final data I need to extract 9 (using 9 dct file for each
>>>>> level) different level files then some of them I need to reshape and
>>>>> then merge them.
>>>>>
>>>>>
>>>>> Hope, I have made my query more clear to you.
>>>>>
>>>>> regards
>>>>> Prakash
>>>>> On Mon, Dec 31, 2012 at 9:48 PM, Nick Cox <njcoxstata@gmail.com> wrote:
>>>>>> You don't comment on my replacement of 9 lines of code with 1.
>>>>>>
>>>>>> Your main loop looks like another -forval- or -foreach- loop but you
>>>>>> don't explain why you want to save different levels in different
>>>>>> datasets.
>>>>>>
>>>>>> Nick
>>>>>>
>>>>>> On Mon, Dec 31, 2012 at 2:27 PM, Prakash Singh <prakashbhu@gmail.com> wrote:
>>>>>>> Nick sorry but that is type error.
>>>>>>> Thanks for the suggestion anyway.
>>>>>>>
>>>>>>> Moreover I am looking some help on creating look so that I can repeat
>>>>>>> the following code for each level 1 to 9.
>>>>>>>
>>>>>>> clear
>>>>>>> set more off
>>>>>>> set mem 500m
>>>>>>> tempfile mydata
>>>>>>> foreach l of numlist 11/19 {
>>>>>>>    infile using D:\TEAM_PC\level`l'.dct, clear
>>>>>>>    capture append using `mydata'
>>>>>>>     save `mydata', replace
>>>>>>> }
>>>>>>> use `mydata', clear
>>>>>>> keep if level==1
>>>>>>> save level1_list.dta", replace
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