Notice: On March 31, it was **announced** that Statalist is moving from an email list to a **forum**. The old list will shut down on April 23, and its replacement, **statalist.org** is already up and running.

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

From |
Tirthankar Chakravarty <tirthankar.chakravarty@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: AW: levelsof problem? |

Date |
Tue, 27 Jul 2010 22:50:06 +0530 |

Nick, Not sure, but I think this: levelsof country if eu==1, local(lev) clean egen eutotal = rowtotal(`lev') will work only if you set -varabbrev- on. The -unab- tip is a good one and I thought about it, but the "US_F" variable could be a moving target (or not). T 2010/7/27 Nick Cox <n.j.cox@durham.ac.uk>: > This problem seems to me simpler than is being implied. > > The direct problem is that that Joe J needs a varlist to feed to -egen-'s -rowtotal()- function. > > His starting point could be the wildcard *_F which catches all the variable names ending in _F. The difficulty is that this includes the US_F variable which for Joe J is a step too far. (At this point I merely hint at the possibility of numerous obvious political jokes without actually making any of them.) > > The command -unab-, although usually billed as a programmer's command, is useful here. It does just one thing, unabbreviate (meaning expand) a varlist to all its implied names, so that > > unab all : *_F > > unpacks all the names of the variables ending in _F and puts the result in a local macro. To remove US_F from the list we can turn to macro manipulation > > local US US_F > local eu : list all - US > > which gives us a macro -eu- containing the desired names. > > Some people might want to emphasise that the varlist expansion is also done by other commands: see e.g. help on -describe, varlist-, -ds-, or -findname- (SJ). But any of those does much more than this one thing, so it is most straightforward to stick to -unab-. > > It also happens that the names of the countries concerned are held as values of Joe J's string variable -country-. The only real problem here is that the list result returned by -levelsof- is complicated by double quote delimiters, but as Tirthankar shows -- and the help file clearly explains -- an option -clean- gets rid of those. > > For Joe J's example dataset > > levelsof country if eu==1, local(lev) clean > egen eutotal = rowtotal(`lev') > > should have worked so far as I can see. There is no need, for the example dataset, to spell out the _F suffix, although Tirthankar's code shows how to do it if needed. > > Confusion on names: Joe J mixed references to > > 1. -egen, rsum()- and -egen, rowtotal()-. > 2. -levels- and -levelsof-. > > In both cases (just a coincidence, this) the second name has been the preferred name since Stata 9. > > Nick > n.j.cox@durham.ac.uk > > joe j > > Thanks a lot, Tirthankar! > > Tirthankar Chakravarty > >> Then this (cumbersome) script should do what you want: >> ********************************************* >> clear >> input str2 country eu GE_F NL_F UK_F US_F >> US 0 1 1 1 0 >> US 0 1 1 1 0 >> NL 1 1 0 1 1 >> IN 0 1 1 1 1 >> GE 1 0 1 1 1 >> GE 1 0 1 1 1 >> US 0 1 1 1 0 >> US 0 1 1 1 0 >> US 0 1 1 1 0 >> PT 1 1 1 1 1 >> end >> g PT_F = 2 >> levelsof country if eu==1, local(lev) clean >> local lev2 >> foreach x of local lev { >> local lev2 " `lev2' `x'_F " >> } >> egen eutotal = rowtotal(`lev2') >> ********************************************* > > joe j > >>> Thanks, Martin. This is not quite what I wanted; The following command >>> is good enough. >>> egen eutotal=rowtotal(GE_F NL_F UK_F) >>> >>> The *_F variables need to be selected based on whether they belong to >>> eu or not (GE_F NL_F UK_F are selected, but not US_F) (The values of >>> _*F variables are not based on whether eu=1 or otherwise). But there >>> are many groupings, like eu, and a lot of countries, so I was looking >>> for an easy method to select. But it seems to me that manual selection >>> is the only choice. > > Martin Weiss > >>>> You could of course -replace- to the values you want based on the -if- >>>> qualifier after the fact: >>>> >>>> >>>> ************* >>>> egen eutotal=rowtotal(GE_F NL_F UK_F) >>>> replace eutotal=. if !eu >>>> ************* >>>> >>>> >>>> The reason that your second approach does not work is that Stata expects a >>>> -varlist- while you feed it >>>> >>>> `"GE"' `"NL"' `"PT"'_F >>>> >>>> which it cannot process. Type -ma di- to see the contents of your -macro-s. > > joe j > >>>> >From a data set roughly like the following >>>> clear >>>> input str2 country eu GE_F NL_F UK_F US_F >>>> US 0 1 1 1 0 >>>> US 0 1 1 1 0 >>>> NL 1 1 0 1 1 >>>> IN 0 1 1 1 1 >>>> GE 1 0 1 1 1 >>>> GE 1 0 1 1 1 >>>> US 0 1 1 1 0 >>>> US 0 1 1 1 0 >>>> US 0 1 1 1 0 >>>> PT 1 1 1 1 1 >>>> end >>>> >>>> I want to calculate the row sum of all *_F variables pertaining to eu >>>> countries (all excluding US_F): >>>> egen eutotal=rowtotal(GE_F NL_F UK_F) >>>> >>>> However, I would prefer to follow some rules in selecting the variables, >>>> like >>>> >>>> levels country if eu==1, local(lev) >>>> egen eutotal=rsum(`lev'_F) >>>> >>>> This doesn't work, however. Any pointers would be appreciated. > > * > * 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/ > -- To every ω-consistent recursive class κ of formulae there correspond recursive class signs r, such that neither v Gen r nor Neg(v Gen r) belongs to Flg(κ) (where v is the free variable of r). * * 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/

**Follow-Ups**:**RE: st: AW: levelsof problem?***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

**References**:**st: levelsof problem?***From:*joe j <joe.stata@gmail.com>

**Re: st: AW: levelsof problem?***From:*joe j <joe.stata@gmail.com>

**Re: st: AW: levelsof problem?***From:*Tirthankar Chakravarty <tirthankar.chakravarty@gmail.com>

**Re: st: AW: levelsof problem?***From:*joe j <joe.stata@gmail.com>

**RE: st: AW: levelsof problem?***From:*"Nick Cox" <n.j.cox@durham.ac.uk>

- Prev by Date:
**st: RE: Re: question about working with dates and times** - Next by Date:
**RE: st: AW: levelsof problem?** - Previous by thread:
**RE: st: AW: levelsof problem?** - Next by thread:
**RE: st: AW: levelsof problem?** - Index(es):