Bookmark and Share

Notice: On March 31, it was announced that Statalist is moving from an email list to a forum. The old list will shut down at the end of May, and its replacement, statalist.org is already up and running.


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: st: Extracting numbers from code


From   Donald Spady <dspady@ualberta.ca>
To   statalist@hsphsun2.harvard.edu
Subject   Re: st: Extracting numbers from code
Date   Mon, 12 Nov 2012 11:46:47 -0700

Daniel
  Don't jump on Sanja.  I wrote her privately because used Statalist to responded initially to her request; however, I never saw my response to her on the Statalist, so I wrote her privately to ensure she got my comment (as to whether or not it was useful is up to her).  For some reason, when I reply on Statalist (not often) I never see my response.  When I submit a new request, no problem.

Don

On 2012-11-12, at 10:21 AM, daniel klein <klein.daniel.81@gmail.com> wrote:

> Sanja,
> 
> it is very important to reply to the list, not write its members
> private messages. One reason for this is, that what you do not
> undestand, others might also find hard to understand, and they will
> benefit from an public answer. This motivates me more to put extra
> effort into an explanation of my code. Second, you get a chance others
> look at my code or modifications, too. In this case this is crucial,
> because my code still does not do the job!
> 
> I will start with an explanation of what the code does.
> 
> The first logical expression
> 
> substr(strofreal(item), 1, 1) == "1"
> 
> checks whether the first character in <item> is a "1" or not. It
> returns "true" (1) if it is, "false" (0) if not. See -help string
> functions- for this. The problem is, that there might be respondents
> who checked items 10 or 11 only. These respondents will be coded as if
> the had checked item 1, even though this is not the case. The line
> 
> !(inlist(substr(strofreal(item), 2, 1), "0", "1"))
> 
> therefore checks, whether the second character in <item> correspoonds
> to a "0" (as is the case for 10) or "1" (as is the case for 11). See
> -help inlist()- for this. The idea is/was not falsly to code those who
> checked either 10 or 11 as if they had checked item 1.
> 
> However, as should be evident, this code does not work either. For
> those who did not only check item 1, but also item 10, or 11, or both,
> the variable <item> will take the values 110, 111, or 11011. With the
> above logic, neither of these cases will be coded correctly, because
> the second character in <item> is a "0" or a "1" in any case. Now, I
> have an ugly work-around for this. It will (probably) work, but it is
> an ad-hoc fix, and not very general. Try
> 
> g byte dummy1 = (substr(strofreal(item), 1, 1) == "1") & ///
> (cond((strlen(strofreal(item)) < 3), ///
> cond(!(inlist(substr(strofreal(item), 2, 1)), "0", "1"), 1, 0), 1))
> 
> See -help cond()- for this.
> 
> Best
> Daniel
> --
> Hi Daniel.
> I just wanted to thank you very much for the answers you just sent me
> on the statalist! They work great!!!! This will save me SO much time.
> If you have a second, could you explain what the second line of code
> does? If not, no problem
> !(inlist(substr(strofreal(item), 2, 1), "0", "1"))
> Thank you again!
> *
> *   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/
> 

Donald Spady

--
dspady@ualberta.ca





*
*   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/


© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   Site index