Re: st: RE: re. strings and non-string: the month case

[Nick Cox <njcoxstata@gmail.com>]

<>

What's more your previous variable is garbage, as first you -encode-d
it without a label specified, so that

"April" meant 1
"August" meant 2

etc.

and then you defined the labels so that 1 means "January". This means that

"April" originals are now "January"
"August" originals are now "February"
etc.

so make sure you start again and destroy the false creations.

Nick
njcoxstata@gmail.com


On 21 November 2013 17:36, Joe Canner <jcanner1@jhmi.edu> wrote:
> As Richard Goldstein noted, you must use the -label- option, which implies that you must also put the label definition before the -encode- statement:
>
> . label define label_mon 1 "Jan" 2 "Feb" 3 "Mar" 4  "Apr" 5 "May" 6 "Jun" 7 "Jul" 8 "Aug" 9 "Sep" 10 "Oct" 11 "Nov" 12 "Dec"
> . enc Month, gen(MONTHS_NUM) label(label_mon)
> . label values  MONTHS_NUM label_mon
>
> Otherwise, encode will use the alphabetical order of months; hence, April is #1, August is #2, etc...
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of PAPANIKOLAOU P.
> Sent: Thursday, November 21, 2013 12:24 PM
> To: statalist@hsphsun2.harvard.edu
> Subject: RE: st: RE: re. strings and non-string: the month case
>
> Dear All,
> Thank you so much.
> I have followed your suggestions through: 1. Use the encode with the generate option, creating a numerical variable.  Use label define and label values, see below.  Following this, I run the tab command to get the frequencies, which are presented in the correct order (jan-Dec).
> But, when I do label list, I do not understand why the list is in different order (1 April, 2 August and so forth) and with the full names of the month. I would have expected to see that the label list would present the months in the jan-dec order. I am confused why this has happened. Would you please let me know.  Many thanks, Panos
>
> enc Month, gen(MONTHS_NUM)
>
> label define label_mon 1 "Jan" 2 "Feb" 3 "Mar" 4  "Apr" 5 "May" 6 "Jun"
> 7 "Jul" 8 "Aug" 9 "Sep" 10 "Oct" 11 "Nov" 12 "Dec"
>
> . label values  MONTHS_NUM label_mon
>
> . tab  MONTHS_NUM
>
>       Month |      Freq.     Percent        Cum.
> ------------+-----------------------------------
>         Jan |        393        8.92        8.92
>         Feb |        330        7.49       16.41
>         Mar |        340        7.72       24.13
>         Apr |        348        7.90       32.03
>         May |        379        8.60       40.64
>         Jun |        376        8.54       49.17
>         Jul |        368        8.35       57.53
>         Aug |        418        9.49       67.01
>         Sep |        423        9.60       76.62
>         Oct |        328        7.45       84.06
>         Nov |        347        7.88       91.94
>         Dec |        355        8.06      100.00
> ------------+-----------------------------------
>       Total |      4,405      100.00
>
> . label list MONTHS_NUM
> MONTHS_NUM:
>            1 April
>            2 August
>            3 December
>            4 February
>            5 January
>            6 July
>            7 June
>            8 March
>            9 May
>           10 November
>           11 October
>           12 September
>
>> -----Original Message-----
>> From: owner-statalist@hsphsun2.harvard.edu
>> [mailto:owner-statalist@hsphsun2.harvard.edu] On Behalf Of Nick Cox
>> Sent: Thursday, November 21, 2013 11:22 AM
>> To: statalist@hsphsun2.harvard.edu
>> Subject: Re: st: RE: re. strings and non-string: the month case
>>
>> understanding what it does and doesn't do is important.
>>
>> Joe is creating a daily date from monthly information alone and then
> extracting the month. That works because it is what is wanted, but the dates themselves are 1 Jan 1960, 1 Feb 1960, and so forth as without a day of the month Stata assumes 1 and without a year it assumes 1960.
>> You discard that day and year  information in this case, but know how
> the trick was done.
>>
>> Nick
>> njcoxstata@gmail.com
>>
>>
>> On 21 November 2013 16:04, Joe Canner <jcanner1@jhmi.edu> wrote:
>>> Panos,
>>>
>>> In conjunction with -encode-, as suggested by Richard Goldstein, you
> might want to use the following statement to convert month names to month numbers:
>>>
>>> . gen month_num=month(date(MONTH,"M"))
>>
>> PAPANIKOLAOU P.
>>
>>> I have got a string variable: MONTH, where records the months of the
> year (e.g., January, February and so forth) on micro-data basis.
>>> Would you please assist me how best I would attach a set of label
> values where 1 refers to January, 2 is for February and so forth.

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/faqs/resources/statalist-faq/
*   http://www.ats.ucla.edu/stat/stata/