sem package fails when no of factors increase from 3 to 4
Dear Xiaoxu LI, sem.mod(mod4, cor18, 500, debug=TRUE) will show you what went wrong with the optimization. Since the three-factor solutions look reasonable, I tried using them to get better start values for the parameters in the four-factor model, producing the solution shown below. As well, I noticed that your correlation matrix was given only to two decimal places, and that some of the correlations have only one significant digit. It's possible, though not necessarily the case, that using a more precise correlation matrix would produce the solution more easily. I hope this helps, John --------------- snip ----------------
mod4 <- specify.model()
1: X1 <-> X1, TD11, 0.30397 2: X2 <-> X2, TD22, 0.33656 3: X3 <-> X3, TD33, 0.48680 4: X4 <-> X4, TD44, 0.62441 5: X5 <-> X5, TD55, 0.78681 6: X6 <-> X6, TD66, 0.68547 7: X7 <-> X7, TD77, 0.79154 8: X8 <-> X8, TD88, 0.67417 9: X9 <-> X9, TD99, 0.60875 10: X10 <-> X10, TDaa, 0.37764 11: X11 <-> X11, TDbb, 0.74658 12: X12 <-> X12, TDcc, 0.85765 13: X1 <- xi1, LY11, 0.83428 14: X2 <- xi1, LY21, 0.81452 15: X3 <- xi1, LY31, 0.71638 16: X4 <- xi2, LY42, 0.61285 17: X5 <- xi2, LY52, 0.46173 18: X6 <- xi2, LY62, 0.56084 19: X7 <- xi3, LY73, 0.45658 20: X8 <- xi3, LY83, 0.57082 21: X9 <- xi3, LY93, 0.62550 22: X10 <- xi4, LXa4, 0.78890 23: X11 <- xi4, LXb4, 0.50340 24: X12 <- xi4, LXc4, 0.37729 25: xi1 <-> xi1, NA, 1 26: xi2 <-> xi2, NA, 1 27: xi3 <-> xi3, NA, 1 28: xi4 <-> xi4, NA, 1 29: xi1 <-> xi2, PH12, 0.13185 30: xi1 <-> xi3, PH13, 0.17445 31: xi2 <-> xi3, PH23, 0.25125 32: xi4 <-> xi1, PH41, 0.35819 33: xi4 <-> xi2, PH42, 0.12253 34: xi4 <-> xi3, PH43, 0.22137 35: Read 34 records
summary(sem(mod4, cor18, 500))
Model Chisquare = 80.675 Df = 48 Pr(>Chisq) = 0.0021920
Chisquare (null model) = 1106.4 Df = 66
Goodness-of-fit index = 0.9747
Adjusted goodness-of-fit index = 0.95888
RMSEA index = 0.036935 90% CI: (0.022163, 0.050657)
Bentler-Bonnett NFI = 0.92708
Tucker-Lewis NNFI = 0.95682
Bentler CFI = 0.9686
SRMR = 0.032512
BIC = -217.63
Normalized Residuals
Min. 1st Qu. Median Mean 3rd Qu. Max.
-1.71000 -0.23300 -0.00337 0.08850 0.26700 2.13000
Parameter Estimates
Estimate Std Error z value Pr(>|z|)
TD11 0.30641 0.037053 8.2694 2.2204e-16 X1 <--> X1
TD22 0.33226 0.037158 8.9419 0.0000e+00 X2 <--> X2
TD33 0.48899 0.039007 12.5358 0.0000e+00 X3 <--> X3
TD44 0.62205 0.076640 8.1165 4.4409e-16 X4 <--> X4
TD55 0.78652 0.063364 12.4126 0.0000e+00 X5 <--> X5
TD66 0.68780 0.070102 9.8114 0.0000e+00 X6 <--> X6
TD77 0.79474 0.062019 12.8144 0.0000e+00 X7 <--> X7
TD88 0.67378 0.069039 9.7595 0.0000e+00 X8 <--> X8
TD99 0.60536 0.075437 8.0247 1.1102e-15 X9 <--> X9
TDaa 0.39902 0.094378 4.2279 2.3590e-05 X10 <--> X10
TDbb 0.74223 0.060911 12.1854 0.0000e+00 X11 <--> X11
TDcc 0.84956 0.060891 13.9523 0.0000e+00 X12 <--> X12
LY11 0.83282 0.040846 20.3895 0.0000e+00 X1 <--- xi1
LY21 0.81715 0.041065 19.8990 0.0000e+00 X2 <--- xi1
LY31 0.71485 0.042041 17.0036 0.0000e+00 X3 <--- xi1
LY42 0.61478 0.066956 9.1818 0.0000e+00 X4 <--- xi2
LY52 0.46204 0.059887 7.7152 1.1990e-14 X5 <--- xi2
LY62 0.55875 0.064082 8.7192 0.0000e+00 X6 <--- xi2
LY73 0.45306 0.058293 7.7721 7.7716e-15 X7 <--- xi3
LY83 0.57116 0.062721 9.1064 0.0000e+00 X8 <--- xi3
LY93 0.62821 0.065434 9.6007 0.0000e+00 X9 <--- xi3
LXa4 0.77523 0.069569 11.1434 0.0000e+00 X10 <--- xi4
LXb4 0.50771 0.056580 8.9733 0.0000e+00 X11 <--- xi4
LXc4 0.38786 0.056614 6.8510 7.3350e-12 X12 <--- xi4
PH12 0.13207 0.064099 2.0604 3.9361e-02 xi2 <--> xi1
PH13 0.17417 0.063512 2.7423 6.1006e-03 xi3 <--> xi1
PH23 0.25059 0.077099 3.2503 1.1529e-03 xi3 <--> xi2
PH41 0.36109 0.055310 6.5285 6.6416e-11 xi1 <--> xi4
PH42 0.12606 0.072905 1.7292 8.3780e-02 xi2 <--> xi4
PH43 0.22301 0.071781 3.1068 1.8913e-03 xi3 <--> xi4
Iterations = 14
Warning message:
In sem.mod(mod4, cor18, 500) :
The following observed variables are in the input covariance or raw-moment
matrix but do not appear in the model:
X13, X14, X15, X16, X17, X18
------------------------------ John Fox, Professor Department of Sociology McMaster University Hamilton, Ontario, Canada web: socserv.mcmaster.ca/jfox
-----Original Message----- From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org]
On
Behalf Of Xiaoxu LI Sent: December-22-08 3:58 PM To: r-help at r-project.org Subject: [R] sem package fails when no of factors increase from 3 to 4 #### I checked through every 3 factor * 3 loading case. #### While, 4 factor * 3 loading failed. #### the data is 6 factor * 3 loading require(sem); cor18<-read.moments(); 1 .68 1 .60 .58 1 .01 .10 .07 1 .12 .04 .06 .29 1 .06 .06 .01 .35 .24 1 .09 .13 .10 .05 .03 .07 1 .04 .08 .16 .10 .12 .06 .25 1 .06 .09 .02 .02 .09 .16 .29 .36 1 .23 .26 .19 .05 .04 .04 .08 .09 .09 1 .11 .13 .12 .03 .05 .03 .02 .06 .06 .40 1 .16 .09 .09 .10 .10 .02 .04 .12 .15 .29 .20 1 .24 .26 .22 .14 .06 .10 .06 .07 .08 .03 .04 .02 1 .21 .22 .29 .07 .05 .17 .12 .06 .06 .03 .12 .04 .55 1 .29 .28 .26 .06 .07 .05 .06 .15 .20 .10 .03 .12 .64 .61 1 .15 .16 .19 .18 .08 .07 .08 .10 .06 .15 .16 .07 .25 .25 .16 1 .24 .20 .16 .13 .15 .18 .19 .18 .14 .11 .07 .16 .19 .21 .22 .35 1 .14 .25 .12 .09 .11 .09 .09 .11 .21 .17 .09 .05 .21 .23 .18 .39 .48 1 mod3.1_9<-specify.model(); X1 <-> X1,TD11,NA X2 <-> X2,TD22,NA X3 <-> X3,TD33,NA X4 <-> X4,TD44,NA X5 <-> X5,TD55,NA X6 <-> X6,TD66,NA X7 <-> X7,TD77,NA X8 <-> X8,TD88,NA X9 <-> X9,TD99,NA X1 <- xi1,LY11, NA X2 <- xi1,LY21, NA X3 <- xi1,LY31, NA X4 <- xi2,LY42, NA X5 <- xi2,LY52, NA X6 <- xi2,LY62, NA X7 <- xi3,LY73, NA X8 <- xi3,LY83, NA X9 <- xi3,LY93, NA xi1 <-> xi1,NA,1 xi2 <-> xi2,NA,1 xi3 <-> xi3,NA,1 xi1 <-> xi2 ,PH12,NA xi1 <-> xi3 ,PH13,NA xi2 <-> xi3 ,PH23,NA mod3.1_6AND10_12<-specify.model(); X1 <-> X1,TD11,NA X2 <-> X2,TD22,NA X3 <-> X3,TD33,NA X4 <-> X4,TD44,NA X5 <-> X5,TD55,NA X6 <-> X6,TD66,NA X10 <-> X10,TD77,NA X11 <-> X11,TD88,NA X12 <-> X12,TD99,NA X1 <- xi1,LY11, NA X2 <- xi1,LY21, NA X3 <- xi1,LY31, NA X4 <- xi2,LY42, NA X5 <- xi2,LY52, NA X6 <- xi2,LY62, NA X10 <- xi3,LY73, NA X11 <- xi3,LY83, NA X12 <- xi3,LY93, NA xi1 <-> xi1,NA,1 xi2 <-> xi2,NA,1 xi3 <-> xi3,NA,1 xi1 <-> xi2 ,PH12,NA xi1 <-> xi3 ,PH13,NA xi2 <-> xi3 ,PH23,NA mod3.1_3AND7_9AND10_12<-specify.model(); X1 <-> X1,TD11,NA X2 <-> X2,TD22,NA X3 <-> X3,TD33,NA X10 <-> X10,TD44,NA X11 <-> X11,TD55,NA X12 <-> X12,TD66,NA X7 <-> X7,TD77,NA X8 <-> X8,TD88,NA X9 <-> X9,TD99,NA X1 <- xi1,LY11, NA X2 <- xi1,LY21, NA X3 <- xi1,LY31, NA X10 <- xi2,LY42, NA X11 <- xi2,LY52, NA X12 <- xi2,LY62, NA X7 <- xi3,LY73, NA X8 <- xi3,LY83, NA X9 <- xi3,LY93, NA xi1 <-> xi1,NA,1 xi2 <-> xi2,NA,1 xi3 <-> xi3,NA,1 xi1 <-> xi2 ,PH12,NA xi1 <-> xi3 ,PH13,NA xi2 <-> xi3 ,PH23,NA mod3.4_6AND7_9AND10_12<-specify.model(); X10 <-> X10,TD11,NA X11 <-> X11,TD22,NA X12 <-> X12,TD33,NA X4 <-> X4,TD44,NA X5 <-> X5,TD55,NA X6 <-> X6,TD66,NA X7 <-> X7,TD77,NA X8 <-> X8,TD88,NA X9 <-> X9,TD99,NA X10 <- xi1,LY11, NA X11 <- xi1,LY21, NA X12 <- xi1,LY31, NA X4 <- xi2,LY42, NA X5 <- xi2,LY52, NA X6 <- xi2,LY62, NA X7 <- xi3,LY73, NA X8 <- xi3,LY83, NA X9 <- xi3,LY93, NA xi1 <-> xi1,NA,1 xi2 <-> xi2,NA,1 xi3 <-> xi3,NA,1 xi1 <-> xi2 ,PH12,NA xi1 <-> xi3 ,PH13,NA xi2 <-> xi3 ,PH23,NA mod4<-specify.model(); X1 <-> X1,TD11,NA X2 <-> X2,TD22,NA X3 <-> X3,TD33,NA X4 <-> X4,TD44,NA X5 <-> X5,TD55,NA X6 <-> X6,TD66,NA X7 <-> X7,TD77,NA X8 <-> X8,TD88,NA X9 <-> X9,TD99,NA X10 <-> X10,TDaa,NA X11 <-> X11,TDbb,NA X12 <-> X12,TDcc,NA X1 <- xi1,LY11, NA X2 <- xi1,LY21, NA X3 <- xi1,LY31, NA X4 <- xi2,LY42, NA X5 <- xi2,LY52, NA X6 <- xi2,LY62, NA X7 <- xi3,LY73, NA X8 <- xi3,LY83, NA X9 <- xi3,LY93, NA X10 <- xi4,LXa4,NA X11 <- xi4,LXb4,NA X12 <- xi4,LXc4,NA xi1 <-> xi1,NA,1 xi2 <-> xi2,NA,1 xi3 <-> xi3,NA,1 xi4 <-> xi4,NA,1 xi1 <-> xi2 ,PH12,NA xi1 <-> xi3 ,PH13,NA xi2 <-> xi3 ,PH23,NA xi4 <-> xi1,PH41,NA xi4 <-> xi2,PH42,NA xi4 <-> xi3,PH43,NA summary(sem(mod3.1_9,cor18,500))$RMSEA; summary(sem(mod3.1_6AND10_12,cor18,500))$RMSEA; summary(sem(mod3.1_3AND7_9AND10_12,cor18,500))$RMSEA; summary(sem(mod3.4_6AND7_9AND10_12,cor18,500))$RMSEA; summary(sem(mod4,cor18,500))$RMSEA;##fail [[alternative HTML version deleted]]
______________________________________________ R-help at r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.