Re: st: changing values of a string variable

[Ronnie Babigumira <rb.glists@gmail.com>]

As they say, there are many ways to skin a cat. 

Here is the label that is automatically created when you simply encode firms

. label list firm1
firm1:
1 id_131
2 id_2837
3 id_6429
4 id_90



So -replace firm1 = . if firm1 != 1- and -replace firm1 = . if firm1 != "id_131":firm1- would do the same thing. The later is closer to what Tashi wanted.

-- 
010100100110111101101110011011100110100101100101




On Tuesday, April 24, 2012 at 10:56 AM, Prakash Singh wrote:

> Thanks Nick for putting my words in a neat way.
> 
> I am not convince why use the command
> replace firm1 = . if firm1 != "id_131":firm1
> when you can use
> replace firm1 = . if firm1 != 1 (suppose the value correnponding to
> the value lebel id_131 is 1 which one can easly get to know)
> 
> Prakash
> 
> On Tue, Apr 24, 2012 at 1:47 PM, Ronnie Babigumira <rb.glists@gmail.com (mailto:rb.glists@gmail.com)> wrote:
> > Nick, this is neat, thanks.
> > 
> > Tashi, this is certainly closer to what you had in mind
> > 
> > encode firms, gen(firm1)
> > replace firm1 = . if firm1 != "id_131":firm1
> > 
> > Ronnie
> > 
> > --
> > 010100100110111101101110011011100110100101100101
> > 
> > 
> > 
> > 
> > On Tuesday, April 24, 2012 at 9:52 AM, Nick Cox wrote:
> > 
> > > Prakash's opening statement is incorrect. If you -encode- a string
> > > variable, it loses no property and indeed stays exactly as it is. What
> > > happens is that a numeric variable is created with value labels equal
> > > to the string values.
> > > 
> > > Tashi appears to be seeking something like the last line here
> > > 
> > > sysuse auto
> > > label def rep78 1 appalling 2 adequate 3 average 4 amazing 5 astounding
> > > label val rep78
> > > 
> > > . count if rep78=="average":rep78
> > > 30
> > > 
> > > For more, see in [U] and e.g.
> > > 
> > > SJ-4-4 dm0009 . . . . . . . Stata tip 14: Using value labels in expressions
> > > . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . K. Higbee
> > > Q4/04 SJ 4(4):488--489 (no commands)
> > > tips for using value labels in expressions
> > > 
> > > Ken Higbee's paper is accessible at
> > > 
> > > http://www.stata-journal.com/sjpdf.html?articlenum=dm0009
> > > 
> > > This syntax has been in Stata a very long time. I don't use it, partly
> > > because I keep forgetting about it and partly because I would need to
> > > look it up to remember what it is, and my wild guess is that many
> > > experienced users would say something similar.
> > > 
> > > Nick
> > > 
> > > 
> > > Prakash Singh [edited slightly]
> > > 
> > > > when you -encode- any variable it loses its string property so
> > > > there would be numeric value corresponding to id_131 in firms1 and you
> > > > should use that value in your command line
> > > 
> > > 
> > > 
> > > 
> > > 
> > > tashi lama
> > > 
> > > > > I found matters similar to what I am going to post have been been discussed in the past but I am not sure if I understood. Here is my dataset
> > > > > 
> > > > > hits firms
> > > > > 3 id_6429
> > > > > 10 id_131
> > > > > 8 id_2837
> > > > > 
> > > > > 12 id_90
> > > 
> > > > > The problem is to have sth like this
> > > > > 
> > > > > hits firms
> > > > > 
> > > > > 3 .
> > > > > 
> > > > > 10 id_131
> > > > > 8 .
> > > > > 
> > > > > 12 .
> > > > > 
> > > > > 
> > > > > so I said 1. encode firm, gen(firm1)
> > > > > 
> > > > > replace firm1=. if firm1!=id_131
> > > > > 
> > > > > drop firms
> > > > > 
> > > > > I also tried 2. replace firms="" if firms!="id_131"
> > > 
> > > > > It didn't give me the expected output although I feel like my codes are correct at least in principle. Any idea?
> > > 
> > > *
> > > * For searches and help try:
> > > * http://www.stata.com/help.cgi?search
> > > * http://www.stata.com/support/statalist/faq
> > > * http://www.ats.ucla.edu/stat/stata/
> > 
> > 
> > 
> > 
> > 
> > *
> > * For searches and help try:
> > * http://www.stata.com/help.cgi?search
> > * http://www.stata.com/support/statalist/faq
> > * http://www.ats.ucla.edu/stat/stata/
> 
> 
> 
> *
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> * http://www.ats.ucla.edu/stat/stata/



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