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

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: Need help with working across variables |

Date |
Sun, 10 Feb 2013 15:15:47 +0000 |

One condition is redundant: gen x = . forval j = 1/4 { replace x = var`j' if missing(x) & inlist(var`j', 1, 2) replace x = . if var`j' != x & var`j' < . } On Sun, Feb 10, 2013 at 10:55 AM, Nick Cox <njcoxstata@gmail.com> wrote: > Corrected version: > > gen x = . > > forval j = 1/4 { > replace x = var`j' if missing(x) & inlist(var`j', 1, 2) > replace x = . if !missing(x, var`j') & var`j' != x > } > > > > On Sun, Feb 10, 2013 at 10:12 AM, Nick Cox <njcoxstata@gmail.com> wrote: >> Here is another way to do it: >> >> gen x = . >> >> forval j = 1/4 { >> replace x = var`j' if missing(x) & inlist(var`j', 1, 2) >> replace x = . if !missing(x) & var`j' != x >> } >> >> So, we initialise to missing; change our minds at the first instance >> of 1 or 2; but change it back again if we see a different value in the >> same observation. >> >> For a review of working rowwise, see >> >> SJ-9-1 pr0046 . . . . . . . . . . . . . . . . . . . Speaking Stata: Rowwise >> (help rowsort, rowranks if installed) . . . . . . . . . . . N. J. Cox >> Q1/09 SJ 9(1):137--157 >> shows how to exploit functions, egen functions, and Mata >> for working rowwise; rowsort and rowranks are introduced >> >> .pdf at http://www.stata-journal.com/sjpdf.html?articlenum=pr0046 >> >> Nick >> >> On Sun, Feb 10, 2013 at 5:34 AM, Cory Smith <corybsmith@gmail.com> wrote: >>> Too complicated in my opinion. >>> >>> gen x = 0 >>> >>> egen Vmin = rowmin(var1 - var4) >>> egen Vmax = rowmax(var1 - var4) >>> >>> replace x = 1 if Vmin == 1 & Vmax == 1 & Vmin != . >>> replace x = 2 if Vmin == 2 & Vmax == 2 & Vmin != . >>> >>> Actually, some of the terms in the above are unnecessary but I kept >>> them in for clarity. >>> >>> On Sun, Feb 10, 2013 at 12:27 AM, Alison Connor <alison.connor@gmail.com> wrote: >>>> Hi Michael, >>>> >>>> There might be a more efficient way to do it, but if you have egenmore >>>> you can do: >>>> >>>> egen x=rall(var1 var2 var3 var4), c(@==1) >>>> >>>> This will be 1 if all non-missing variables are 1, and 0 otherwise. If >>>> you only have two values for your variables, then you can run this >>>> command again, and then merge the two into a third variable: >>>> >>>> egen x1=rall(var1 var2 var3 var4), c(@==1) >>>> egen x2=rall(var1 var2 var3 var4), c(@==2) >>>> >>>> gen x=0 >>>> replace x=1 if x1==1 >>>> replace x=2 if x2==1 >>>> >>>> If you are going to do this for multiple values, then you can create a loop: >>>> >>>> gen x=0 >>>> forvalues i=1/2 { >>>> egen x`i'=rall(var1 var2 var3 var4), c(@==`i') >>>> replace x=`i' if x`i'==1 >>>> drop x`i' >>>> } >> >> On Sun, Feb 10, 2013 at 10:41 AM, Michael Stewart >> <michaelstewartresearch@gmail.com> wrote: >> >>>>> Here is my data format and my question: >>>>> id var1 var2 var3 var4 >>>>> 1 1 1 1 . >>>>> 2 1 1 1 1 >>>>> 3 1 2 1 . >>>>> 4 2 2 2 2 >>>>> 5 1 1 1 1 >>>>> 6 1 2 . . >>>>> 7 2 1 2 . >>>>> >>>>> I am trying to generate a new variable x =1 if all non missings values >>>>> for the variables(per observation) are equal to 1 and x =2 if all non >>>>> missings values for the variables(per observation) are equal to 2. I >>>>> tried to do foreach loop like >>>>> >>>>> gen x=0 >>>>> foreach x in var1 var2 var3 var4{ >>>>> replace x=1 if `x'=1 >>>>> } >>>>> but it doesnt seem to do the trick >>>>> >>>>> I am specifically interested in to change x =1 if all nonmissign >>>>> values for an observation are equal to one >>>>> For example: I would like to replace x=1 for id=1 but not for id 3 >>>>> Similarly, I would like to replace x=2 if all nom missing values for >>>>> an observation are equal to two. >>> * * 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 with working across variables***From:*Michael Stewart <michaelstewartresearch@gmail.com>

**References**:**st: Need help with working across variables***From:*Michael Stewart <michaelstewartresearch@gmail.com>

**Re: st: Need help with working across variables***From:*Alison Connor <alison.connor@gmail.com>

**Re: st: Need help with working across variables***From:*Cory Smith <corybsmith@gmail.com>

**Re: st: Need help with working across variables***From:*Nick Cox <njcoxstata@gmail.com>

**Re: st: Need help with working across variables***From:*Nick Cox <njcoxstata@gmail.com>

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