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From |
Nick Cox <njcoxstata@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Need help converting values into factor variable |

Date |
Sat, 1 Dec 2012 12:53:53 +0000 |

sum() create running sum (see -help sum()-) year != year[_n-1] year not equal to previous year expression evaluated as 1 if true and 0 if false see FAQ . . . . . . . . . . . . . . . . . . . . . . . True and false in Stata . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . N. J. Cox 2/03 What is true and false in Stata? http://www.stata.com/support/faqs/data-management/true-and-false/ This works also for the _first_ observation for each patient as the previous year is then evaluated as missing (which is fine; missing is not any of 2009 ... 2012) inrange(year, 2009, 2012) year in range 2009 to 2012 (may be superfluous if you _don't_ have other years -- but you did not say that) Nick On Sat, Dec 1, 2012 at 12:44 PM, Michael Stewart <michaelstewartresearch@gmail.com> wrote: > I am trying to decipher the code written by you(sort, I am by no means > and stata expert ) > Can you explain what this code is doing; especially the argument ( > sum(year != year[_n-1] & >> inrange(year, 2009, 2012)) On Sat, Dec 1, 2012 at 7:17 AM, Nick Cox <njcoxstata@gmail.com> wrote: >> This is not "Statlist"! >> >> You should show us your code that you tried to get an explanation of >> what you are getting wrong. >> >> bysort patient (year) : gen flag = sum(year != year[_n-1] & >> inrange(year, 2009, 2012)) >> by patient : replace flag = flag[_N] >> >> Nick >> >> On Sat, Dec 1, 2012 at 11:55 AM, Michael Stewart >> <michaelstewartresearch@gmail.com> wrote: >> >>> Dear Statlist reader , >>> I am having trouble converting my values into factor variables and am >>> looking for help. My data looks as follows where "patientid" is pt >>> identification number and "year_elevated" is year in which a >>> particular lab value was elevated >>> >>> >>> patientid year_elevated >>> 111 2009 >>> 111 2009 >>> 222 2009 >>> 222 2011 >>> 222 2012 >>> 333 2009 >>> 333 2012 >>> 444 2011 >>> 444 2012 >>> 555 2009 >>> 555 2010 >>> 555 2011 >>> 555 2012 >>> >>> I want to create a factor variable (y )with values 1= ,2 , 3 and 4 >>> where for each distinct patientid >>> y=1 if year_elevated has anyone of ( 2009 or 2010 or 2011 or 2012) values >>> y=2 if year_elevated has any two of ( 2009 , 2010 , 2011 , 2012) values >>> y=3 if year_elevated has any three of ( 2009 , 2010 , 2011 , 2012) values >>> y=4 if year_elevated has all four of ( 2009 , 2010 , 2011 , 2012) values * * 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/

**Follow-Ups**:**Re: st: Need help converting values into factor variable***From:*Michael Stewart <michaelstewartresearch@gmail.com>

**References**:**st: Need help converting values into factor variable***From:*Michael Stewart <michaelstewartresearch@gmail.com>

**Re: st: Need help converting values into factor variable***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Need help converting values into factor variable***From:*Michael Stewart <michaelstewartresearch@gmail.com>

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