Notice: On April 23, 2014, Statalist moved from an email list to a forum, based at statalist.org.
From | Stas Kolenikov <skolenik@gmail.com> |
To | statalist@hsphsun2.harvard.edu |
Subject | Re: st: Constructing a variable from standard deviations |
Date | Sun, 21 Nov 2010 18:06:18 -0600 |
I am totally lost. So where are these standard deviations coming from? On Sun, Nov 21, 2010 at 5:33 AM, M.P.J. van Zaal <Matthias.vanZaal@student.uva.nl> wrote: > Thanks for your help mr Kolenikov. > > However, im not sure the tips you gave me adress my problem. I will > rephrase in more detail: > > The goal of my analysis is the examine sorting effects. The standard > deviations are measures of risk of different options individuals have. > The individuals sort themself in one of those options by choosing a > risk level of the liking. The 106 standard deviations are thus the > different possible "types" of the individuals in the sample. > I want to have a variable with the 106 different standard deviations > so i can use it as dependent variable in my regression. > > The 106 standard deviations have ofcourse different frequencies, > because some options are more frequently chosen. Do you think i should > incorporate this? > > Anyways, it would be awesome if you can give me some usefull STATA > procedures. Other STATAlist users are ofcourse also welcome to give > their advice! > > regards, > > Mathijs (first timer in a real research project involving stata) > > > > ----- Original Message ----- > From: Stas Kolenikov <skolenik@gmail.com> > Date: Sunday, November 21, 2010 0:26 am > Subject: Re: st: Constructing a variable from standard deviations > To: statalist@hsphsun2.harvard.edu > >> -tabstat- is far from the most appropriate command for this purpose. >> There are several ways to achieve what you need. >> >> 1. Use -egen- command: >> >> egen sdy = sd( y ) >> >> 2. Use saved results from -summarize- (type -return list- to find out >> what these are): >> >> sum y >> gen sdy = r(sd) >> >> I personally think that having a variable equal to a constant is a >> data management oxymoron... variable must vary, by the virtue of its >> name :). You probably only need it for another step or two in data >> analysis, e.g., if you want to simulate a new set of errors with the >> same variance: >> >> sum y >> gen new_y = rnormal()*r(sd) >> >> On Sat, Nov 20, 2010 at 9:36 AM, M.P.J. van Zaal >> <Matthias.vanZaal@student.uva.nl> wrote: >> > Dear reader, >> > >> > I have a problem with constructing a new a variable from the >> standard> deviations of regressions residuals. I have generated >> 104 different >> > regression residuals and then use tabstat to determine their >> standard> deviations. I need to construct a new variable from >> these 104 standard >> > deviations of the regression residuals for the next step in my >> analysis.> >> > I know that the tabstat has a save options to save the summary >> > statistics in a matrix. Unfortunately when I use this option no >> matrix> is created (nothing happens). Does anyone know how i can >> save the >> > standard deviations in as a new variable, possible using tabstat or >> > another method. >> > >> > Thanks for your attention and help >> > >> > regards, >> > >> > Mathijs >> > * >> > * 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/ >> > >> >> >> >> -- >> Stas Kolenikov, also found at http://stas.kolenikov.name >> Small print: I use this email account for mailing lists only. >> >> * >> * 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/ > -- Stas Kolenikov, also found at http://stas.kolenikov.name Small print: I use this email account for mailing lists only. * * 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/