I am trying to do a user-specified contrast in a single factor repeated mea= sures design. These are fictions data. This is a one-way, repeated measures with measure= s at four time points. Variables are: Time 1, Time 2, Time 3, Time 4, N = =3D 10. =20 There is essentially no difference from T1 to T2. Improvement at T3. More= improvement at T4. =20 I want syntax for a contrast comparison for the following: T1 & 2 vs 3 T1 & 2 vs 4 3 vs 4 Here is the syntax I=E2=80=99m using: MANOVA time1 time2 time3 time4 /TRANSFORM(time1 time2 time3 time4)=3DSPECIAL (1 1 1 1, -1 -1 2 0, -1 -1 0 = 2, 0 0 1 -1) /RENAME=3Dskip one2vs3 one2vs4 threevs4. Here is the error message: Error # 12265 >Singular matrix for MANOVA--The special transformation matrix is singular. >The analysis is terminated. The problem appears to be with the last contrast: 0 0 -1 1 If I change it to anything else, the syntax works. For example, it works i= f I replace the last comparison with any of the following: 1 0 -1 0 0 -1 -1 2 -1 0 0 1 And on and on=E2=80=A6 Thoughts?

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11/12/2016 8:43:42 PM

On Sat, 12 Nov 2016 12:43:42 -0800 (PST), KSM <kand.mcqueen@gmail.com> wrote: >I am trying to do a user-specified contrast in a single factor repeated measures design. > >These are fictions data. This is a one-way, repeated measures with measures at four time points. Variables are: Time 1, Time 2, Time 3, Time 4, N = 10. > >There is essentially no difference from T1 to T2. Improvement at T3. More improvement at T4. > >I want syntax for a contrast comparison for the following: > >T1 & 2 vs 3 >T1 & 2 vs 4 >3 vs 4 > >Here is the syntax I’m using: > >MANOVA time1 time2 time3 time4 >/TRANSFORM(time1 time2 time3 time4)=SPECIAL (1 1 1 1, -1 -1 2 0, -1 -1 0 2, 0 0 1 -1) >/RENAME=skip one2vs3 one2vs4 threevs4. > >Here is the error message: > >Error # 12265 >>Singular matrix for MANOVA--The special transformation matrix is singular. >>The analysis is terminated. > >The problem appears to be with the last contrast: 0 0 -1 1 That is because it is, in its effect, exact the same as the difference, (contrast 1 minus contrast 2), so the matrix is singular. If that isn't obvious: Your groups 1&2 are treated together, so imagine that you have only 3 groups. With 3 groups, you can only have two independent contrasts since the d.f is 2. So you could not, independently, contrast 1 to 2, 1 to 3, and 2 to 3. That's what your dependency looks like. > >If I change it to anything else, the syntax works. For example, it works if I replace the last comparison with any of the following: > >1 0 -1 0 >0 -1 -1 2 >-1 0 0 1 > >And on and on… > >Thoughts? -- Rich Ulrich

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11/12/2016 9:47:58 PM

On Saturday, November 12, 2016 at 3:43:45 PM UTC-5, KSM wrote: > I am trying to do a user-specified contrast in a single factor repeated m= easures design. >=20 > These are fictions data. This is a one-way, repeated measures with measu= res at four time points. Variables are: Time 1, Time 2, Time 3, Time 4, N= =3D 10. =20 >=20 > There is essentially no difference from T1 to T2. Improvement at T3. Mo= re improvement at T4. =20 >=20 > I want syntax for a contrast comparison for the following: >=20 > T1 & 2 vs 3 > T1 & 2 vs 4 > 3 vs 4 >=20 > Here is the syntax I=E2=80=99m using: >=20 > MANOVA time1 time2 time3 time4 > /TRANSFORM(time1 time2 time3 time4)=3DSPECIAL (1 1 1 1, -1 -1 2 0, -1 -1 = 0 2, 0 0 1 -1) > /RENAME=3Dskip one2vs3 one2vs4 threevs4. >=20 > Here is the error message: >=20 > Error # 12265 > >Singular matrix for MANOVA--The special transformation matrix is singula= r. > >The analysis is terminated. >=20 > The problem appears to be with the last contrast: 0 0 -1 1 >=20 > If I change it to anything else, the syntax works. For example, it works= if I replace the last comparison with any of the following: >=20 > 1 0 -1 0 > 0 -1 -1 2 > -1 0 0 1 >=20 > And on and on=E2=80=A6 >=20 > Thoughts? I think that if you restructure your data from WIDE to LONG, and then use M= IXED to carry out the analysis, you might find its TEST sub-command easier = to work with than the special contrasts from either MANOVA or GLM. E.g.,= =20 COMPUTE Case =3D $CASENUM. FORMATS Case (F5.0). VARSTOCASES /MAKE Y FROM Time1 Time2 Time3 Time4 /INDEX=3DTime(4)=20 /KEEP=3DCase=20 /NULL=3DKEEP. MIXED Y BY Time /FIXED =3D Time /REPEATED =3D Time | SUBJECT(Case) COVTYPE(CS) /EMMEANS TABLES(Time) COMPARE /TEST "[1,2] v 3" ALL 0 1 1 -2 0 /TEST "[1,2] v 4" ALL 0 1 1 0 -2 /TEST "3 v 4" ALL 0 0 0 1 -1 .. HTH.

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11/14/2016 2:28:41 PM