Fisher LSD test following MANOVA?

[Zack Berman]

Hey everyone,

I'm wondering if there is any way to use Fisher's post hoc LSD test after a MANOVA in stata? I need to run this test for a class but can't find any command language that runs this test. Really don't want to have to jump over to SPSS ;P

Thanks!

[Joseph Coveney]

Yes, there's a way: you can use Stata's -pwcompare- after -manova-, specifying the equation(s) as desired. See below for an illustration of the command language:

The illustration uses the worked example shown in the YouTube video here. The illustration follows along with the SPSS worked example in that video, showing that the analogous results from Stata match those for SPSS at the video's elapsed times noted in the comments below.

.ÿ
.ÿversionÿ17.0

.ÿ
.ÿclearÿ*

.ÿ
.ÿ/*ÿDatasetÿsourceÿ
>ÿÿÿÿproximalÿhttps://www.randomservices.org/random/data/Cicada.html
>ÿÿÿÿreferenceÿ"Theÿtableÿbelowÿgivesÿtheÿbodyÿweightÿ(inÿgrams),ÿbodyÿlength,ÿ
>ÿÿÿÿwingÿlength,ÿwingÿwidthÿ(inÿmillimeters),ÿgenderÿ(0ÿfemale,ÿ1ÿmale),ÿandÿ
>ÿÿÿÿspeciesÿ(0ÿtredecula,ÿ1ÿtredecassini,ÿ2ÿtredecim)ÿforÿaÿsampleÿofÿ13-yearÿ
>ÿÿÿÿcicadasÿ(Magicicada)ÿcollectedÿinÿtheÿmiddleÿTennesseeÿarea.ÿTheÿnumberÿ
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.ÿ
.ÿimportÿexcelÿ"CicadaÿData.xlsx",ÿsheet(Sheet1)ÿcellrange(A2:G106)ÿfirstrow
(7ÿvars,ÿ104ÿobs)

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.ÿ
.ÿrenameÿgÿsex

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.ÿ
.ÿ//ÿFollowingÿSPSSÿworkedÿexampleÿhereÿhttps://www.youtube.com/watch?v=YAhZvp8IU4Q
.ÿmanovaÿbwÿwlÿblÿ=ÿspecies

ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿNumberÿofÿobsÿ=ÿÿÿÿÿÿÿÿ104

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ÿÿÿÿÿÿÿÿÿÿ-----------+-------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿÿspeciesÿ|Wÿÿÿ0.7819ÿÿÿÿÿÿÿÿÿ2ÿÿÿÿÿÿ6.0ÿÿÿÿ198.0ÿÿÿÿÿ4.32ÿ0.0004ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Pÿÿÿ0.2276ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ6.0ÿÿÿÿ200.0ÿÿÿÿÿ4.28ÿ0.0004ÿa
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Lÿÿÿ0.2669ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ6.0ÿÿÿÿ196.0ÿÿÿÿÿ4.36ÿ0.0004ÿa
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ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|-------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿResidualÿ|ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ101
ÿÿÿÿÿÿÿÿÿÿ-----------+-------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿTotalÿ|ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ103
ÿÿÿÿÿÿÿÿÿÿ-------------------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿeÿ=ÿexact,ÿaÿ=ÿapproximate,ÿuÿ=ÿupperÿboundÿonÿF

.ÿ
.ÿ//ÿMatchesÿLSDÿresultsÿforÿBWÿshownÿinÿtableÿatÿ2:43–3:10ÿinÿvideo
.ÿpwcompareÿspecies,ÿpveffects

Pairwiseÿcomparisonsÿofÿmarginalÿlinearÿpredictions

Margins:ÿasbalanced

-------------------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿUnadjusted
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|ÿÿÿContrastÿÿÿStd.ÿerr.ÿÿÿÿÿÿtÿÿÿÿP>|t|
---------------------------+---------------------------------------
bwÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿspeciesÿ|
TredecassiniÿvsÿTredeculaÿÿ|ÿÿÿÿÿÿ.0175ÿÿÿ.0118063ÿÿÿÿÿ1.48ÿÿÿ0.141
ÿÿÿÿTredecimÿvsÿTredeculaÿÿ|ÿÿÿÿÿÿ.0575ÿÿÿ.0252992ÿÿÿÿÿ2.27ÿÿÿ0.025
ÿTredecimÿvsÿTredecassiniÿÿ|ÿÿÿÿÿÿÿÿ.04ÿÿÿ.0250165ÿÿÿÿÿ1.60ÿÿÿ0.113
-------------------------------------------------------------------

.ÿ
.ÿ//ÿMatchesÿLSDÿresultsÿforÿWLÿshownÿinÿtableÿatÿ5:14–5:56ÿinÿvideo
.ÿpwcompareÿspecies,ÿpveffectsÿequation(wl)

Pairwiseÿcomparisonsÿofÿmarginalÿlinearÿpredictions

Margins:ÿasbalanced

-------------------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿUnadjusted
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---------------------------+---------------------------------------
wlÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|
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TredecassiniÿvsÿTredeculaÿÿ|ÿÿÿ1.188552ÿÿÿ.4466308ÿÿÿÿÿ2.66ÿÿÿ0.009
ÿÿÿÿTredecimÿvsÿTredeculaÿÿ|ÿÿÿ1.484848ÿÿÿ.9570661ÿÿÿÿÿ1.55ÿÿÿ0.124
ÿTredecimÿvsÿTredecassiniÿÿ|ÿÿÿ.2962963ÿÿÿ.9463722ÿÿÿÿÿ0.31ÿÿÿ0.755
-------------------------------------------------------------------

.ÿ
.ÿ//ÿConsiderÿalso
.ÿmatrixÿdefineÿTredeculavTredecassiniÿ=ÿ(1,ÿ-1,ÿ0,ÿ0)

.ÿmanovatestÿ,ÿtest(TredeculavTredecassini)

ÿTestÿconstraint
ÿ(1)ÿÿÿÿ0.speciesÿ-ÿ1.speciesÿ=ÿ0

ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿWÿ=ÿWilks'ÿlambdaÿÿÿÿÿÿLÿ=ÿLawley-Hotellingÿtrace
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿPÿ=ÿPillai'sÿtraceÿÿÿÿÿRÿ=ÿRoy'sÿlargestÿroot

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ÿÿÿÿÿÿÿÿÿÿ-----------+-------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿmanovatestÿ|Wÿÿÿ0.9319ÿÿÿÿÿÿÿÿÿ1ÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ2.41ÿ0.0714ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Pÿÿÿ0.0681ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ2.41ÿ0.0714ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Lÿÿÿ0.0731ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ2.41ÿ0.0714ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Rÿÿÿ0.0731ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ2.41ÿ0.0714ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|-------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿResidualÿ|ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ101
ÿÿÿÿÿÿÿÿÿÿ-------------------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿeÿ=ÿexact,ÿaÿ=ÿapproximate,ÿuÿ=ÿupperÿboundÿonÿF

.ÿ/*ÿcf.ÿhotellingÿbwÿwlÿblÿifÿinlist(species,ÿ"Tredecula":Species,ÿ"Tredecassini":Species),ÿby(species)ÿnotableÿ*/
.ÿ
.ÿmatrixÿdefineÿTredeculavTredecimÿ=ÿ(1,ÿ0,ÿ-1,ÿ0)

.ÿmanovatestÿ,ÿtest(TredeculavTredecim)

ÿTestÿconstraint
ÿ(1)ÿÿÿÿ0.speciesÿ-ÿ2.speciesÿ=ÿ0

ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿWÿ=ÿWilks'ÿlambdaÿÿÿÿÿÿLÿ=ÿLawley-Hotellingÿtrace
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿPÿ=ÿPillai'sÿtraceÿÿÿÿÿRÿ=ÿRoy'sÿlargestÿroot

ÿÿÿÿÿÿÿÿÿÿÿÿÿÿSourceÿ|ÿStatisticÿÿÿÿÿÿÿÿdfÿÿÿÿF(df1,ÿÿÿÿÿdf2)ÿ=ÿÿÿFÿÿÿProb>F
ÿÿÿÿÿÿÿÿÿÿ-----------+-------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿmanovatestÿ|Wÿÿÿ0.8275ÿÿÿÿÿÿÿÿÿ1ÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ6.88ÿ0.0003ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Pÿÿÿ0.1725ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ6.88ÿ0.0003ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Lÿÿÿ0.2085ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ6.88ÿ0.0003ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Rÿÿÿ0.2085ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ6.88ÿ0.0003ÿe
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ÿÿÿÿÿÿÿÿÿÿÿÿResidualÿ|ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ101
ÿÿÿÿÿÿÿÿÿÿ-------------------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿeÿ=ÿexact,ÿaÿ=ÿapproximate,ÿuÿ=ÿupperÿboundÿonÿF

.ÿ/*ÿcf.ÿhotellingÿbwÿwlÿblÿifÿinlist(species,ÿ"Tredecula":Species,ÿ"Tredecim":Species),ÿby(species)ÿnotableÿ*/
.ÿ
.ÿmatrixÿdefineÿTredecassinivTredecimÿ=ÿ(0,ÿ1,ÿ-1,ÿ0)

.ÿmanovatestÿ,ÿtest(TredecassinivTredecim)

ÿTestÿconstraint
ÿ(1)ÿÿÿÿ1.speciesÿ-ÿ2.speciesÿ=ÿ0

ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿWÿ=ÿWilks'ÿlambdaÿÿÿÿÿÿLÿ=ÿLawley-Hotellingÿtrace
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿPÿ=ÿPillai'sÿtraceÿÿÿÿÿRÿ=ÿRoy'sÿlargestÿroot

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ÿÿÿÿÿÿÿÿÿÿ-----------+-------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿmanovatestÿ|Wÿÿÿ0.8550ÿÿÿÿÿÿÿÿÿ1ÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ5.60ÿ0.0014ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Pÿÿÿ0.1450ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ5.60ÿ0.0014ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Lÿÿÿ0.1696ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ5.60ÿ0.0014ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|Rÿÿÿ0.1696ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ3.0ÿÿÿÿÿ99.0ÿÿÿÿÿ5.60ÿ0.0014ÿe
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ|-------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿResidualÿ|ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ101
ÿÿÿÿÿÿÿÿÿÿ-------------------------------------------------------------------
ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿeÿ=ÿexact,ÿaÿ=ÿapproximate,ÿuÿ=ÿupperÿboundÿonÿF

.ÿ/*ÿcf.ÿhotellingÿbwÿwlÿblÿifÿinlist(species,ÿ"Tredecassini":Species,ÿ"Tredecim":Species),ÿby(species)ÿnotableÿ*/
.ÿ
.ÿexit

endÿofÿdo-file


.

[Zack Berman]

Thank you!