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From |
"Austin Nichols" <austinnichols@gmail.com> |

To |
statalist@hsphsun2.harvard.edu |

Subject |
Re: st: working with a vector and scalars |

Date |
Sun, 8 Jun 2008 21:00:38 -0400 |

Cathy L. Antonakos <cathya@umich.edu> I take it you don't want the reliability reported by -loneway-? Not sure what you want from your description... but I don't think that equation looks right, and I don't have the ref handy. Can you confirm that t cancels out? Is your calculated s equiv to d in your formula? I don't see where you've tried to calculate something and gotten an error, but try: egen N = count(crowdindx), by(placeXhr) g nr=1/N mean nr, over(placeXhr) mat b=e(b) mat N=b' loneway crowdindx placeXhr scalar t = r(sd_b) * r(sd_b) scalar s = r(sd_w) * r(sd_w) mat lambda = s*N mat li lamdba But if you need to calculate the element-wise reciprocal, it's easier in Mata... On Sun, Jun 8, 2008 at 8:23 PM, Cathy L. Antonakos <cathya@umich.edu> wrote: > I am working with scalars and a vector to estimate sample mean reliability > by group, using a formula from Bryk & Raudenbush (1992) Hierarchical Linear > Models: > > lambda-j = t / [ t / (d /Nj)] > > lambda-j is the reliability estimate for group j, t is between-group > variance, d is within-group variance, and Nj is the group N. > > Nj is a vector. The other parameters (t, d) are scalars. > > Here's what I tried using -matrix- and -scalar-. The vector comes from a > collapsed dataset. The scalars come from -loneway- using the original > (uncollapsed) dataset. I have no trouble producing the vector and scalars, > but can't figure out how to get them into the same matrix or file together > so I can calculate the reliability esimates. > > Any help will be much appreciated. > > Cathy Antonakos > > -------------- > . bys placeXhr: egen N = count(crowdindx) > . preserve > . collapse (max) N, by(placeXhr) > . mkmat N > . levelsof placeXhr, local(l) > . matrix rownames N = `l' . matrix list N > > N[49,1] > N > 2_10 2 > 2_11 81 > 2_12 150 > 2_13 340 > 2_14 138 > 2_15 82 > 2_16 102 > 2_17 119 > 2_18 288 > 2_19 160 > 2_8 48 > 2_9 265 > 3_10 166 > 3_11 71 > 3_12 63 > 3_13 25 > 3_14 53 > 3_15 68 > 3_16 44 > 3_17 61 > 3_18 33 > 3_19 35 > 3_8 36 > 3_9 16 > 6_10 33 > 6_11 69 > 6_12 82 > 6_13 30 > 6_14 87 > 6_15 90 > 6_16 90 > 6_17 92 > 6_18 63 > 6_19 79 > 6_8 86 > 6_9 41 > 9_10 57 > 9_11 135 > 9_12 113 > 9_13 83 > 9_14 152 > 9_15 168 > 9_16 160 > 9_17 151 > 9_18 97 > 9_19 147 > 9_8 216 > 9_9 166 > 9_9 190 > > . restore > > . *create matrices from -loneway- parameter estimates. > . preserve > . loneway crowdindx placeXhr > > One-way Analysis of Variance for crowdindx: Crowding Index (wtd. sum) > > Number of obs = 5121 > R-squared = 0.5384 > > Source SS df MS F Prob > F > ------------------------------------------------------------------------- > Between placeXhr 682650.69 47 14524.483 125.87 0.0000 > Within placeXhr 585364.53 5073 115.38824 > ------------------------------------------------------------------------- > Total 1268015.2 5120 247.65922 > > Intraclass Asy. > correlation S.E. [95% Conf. Interval] > ------------------------------------------------ > 0.54152 0.06135 0.42126 0.66177 > > Estimated SD of placeXhr effect 11.67412 > Estimated SD within placeXhr 10.74189 > Est. reliability of a placeXhr mean 0.99206 > (evaluated at n=105.73) > > . return list > > scalars: > r(lb) = .4212643949911408 > r(ub) = .6617675540515819 > r(se) = .0613539740927638 > r(sd_w) = 10.74189173110937 > r(sd_b) = 11.67412402231762 > r(rho_t) = .9920556043556278 > r(rho) = .5415159745213614 > r(N) = 5121 > > . scalar t = r(sd_b) * r(sd_b) . scalar s = r(sd_w) * r(sd_w) > . restore > > * > * For searches and help try: > * http://www.stata.com/support/faqs/res/findit.html > * http://www.stata.com/support/statalist/faq > * http://www.ats.ucla.edu/stat/stata/ > * * For searches and help try: * http://www.stata.com/support/faqs/res/findit.html * http://www.stata.com/support/statalist/faq * http://www.ats.ucla.edu/stat/stata/

**Follow-Ups**:**Re: st: working with a vector and scalars***From:*"Cathy L. Antonakos" <cathya@umich.edu>

**References**:**st: working with a vector and scalars***From:*"Cathy L. Antonakos" <cathya@umich.edu>

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