Praktikum 10

Materi: Model Log Linear untuk Data Respon Poisson

Penyelesaian dengan bantuan program R

Definisi Peubah

X = Information Program Opinion (I)

Y = Health Care Opinion (H)

Z = Gender (G)

## Program R P10 Materi Praktikum (2) Problem 8.1 (Agresti,hlm.347) ##

##=====================## 
# INPUT DATA 
##=====================## 
z.gender<-factor(rep(c("1M","2F"),each=4)) 
x.IO<-factor(rep(c("1support","2oppose"),each=2,times=2)) 
y.HO<-factor(rep(c("1support","2oppose"),times=4)) 
counts<-c(76,160,6,25,114,181,11,48) 
data.frame(z.gender,x.IO,y.HO,counts) 
##   z.gender     x.IO     y.HO counts
## 1       1M 1support 1support     76
## 2       1M 1support  2oppose    160
## 3       1M  2oppose 1support      6
## 4       1M  2oppose  2oppose     25
## 5       2F 1support 1support    114
## 6       2F 1support  2oppose    181
## 7       2F  2oppose 1support     11
## 8       2F  2oppose  2oppose     48
##=============================## 
# Penentuan kategori reference
##=============================##
x.IO<-relevel(x.IO,ref="2oppose") 
y.HO<-relevel(y.HO,ref="2oppose") 
z.gender<-relevel(z.gender,ref="2F")

##=====================## 
# Model 1: Saturated model
##=====================##
#saturated 
model1<- glm(counts~x.IO+y.HO+z.gender+x.IO*y.HO+x.IO*z.gender+ y.HO*z.gender+x.IO*y.HO*z.gender,            
            family=poisson("link"=log)) 
summary(model1)
## 
## Call:
## glm(formula = counts ~ x.IO + y.HO + z.gender + x.IO * y.HO + 
##     x.IO * z.gender + y.HO * z.gender + x.IO * y.HO * z.gender, 
##     family = poisson(link = log))
## 
## Deviance Residuals: 
## [1]  0  0  0  0  0  0  0  0
## 
## Coefficients:
##                                      Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                           3.87120    0.14434  26.820  < 2e-16 ***
## x.IO1support                          1.32730    0.16235   8.175 2.95e-16 ***
## y.HO1support                         -1.47331    0.33428  -4.407 1.05e-05 ***
## z.gender1M                           -0.65233    0.24664  -2.645  0.00817 ** 
## x.IO1support:y.HO1support             1.01101    0.35502   2.848  0.00440 ** 
## x.IO1support:z.gender1M               0.52900    0.26946   1.963  0.04962 *  
## y.HO1support:z.gender1M               0.04619    0.56428   0.082  0.93476    
## x.IO1support:y.HO1support:z.gender1M -0.32833    0.59339  -0.553  0.58005    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for poisson family taken to be 1)
## 
##     Null deviance:  4.4582e+02  on 7  degrees of freedom
## Residual deviance: -2.1094e-14  on 0  degrees of freedom
## AIC: 61.382
## 
## Number of Fisher Scoring iterations: 3
##=====================## 
#Model 2: Interaksi XY XZ YZ (Interaksi GH,GI,HI)
##=====================## 
#Homogenous Model  
model2 <- glm(counts~x.IO+y.HO+z.gender+x.IO*y.HO+x.IO*z.gender+ y.HO*z.gender,              
              family=poisson("link"=log))
summary(model2)
## 
## Call:
## glm(formula = counts ~ x.IO + y.HO + z.gender + x.IO * y.HO + 
##     x.IO * z.gender + y.HO * z.gender, family = poisson(link = log))
## 
## Deviance Residuals: 
##        1         2         3         4         5         6         7         8  
## -0.10362   0.07183   0.39073  -0.17923   0.08516  -0.06730  -0.26626   0.13173  
## 
## Coefficients:
##                           Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                 3.8521     0.1415  27.219  < 2e-16 ***
## x.IO1support                1.3514     0.1575   8.578  < 2e-16 ***
## y.HO1support               -1.3750     0.2750  -5.001 5.71e-07 ***
## z.gender1M                 -0.5976     0.2242  -2.666  0.00768 ** 
## x.IO1support:y.HO1support   0.8997     0.2852   3.155  0.00160 ** 
## x.IO1support:z.gender1M     0.4636     0.2406   1.927  0.05401 .  
## y.HO1support:z.gender1M    -0.2516     0.1749  -1.438  0.15035    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for poisson family taken to be 1)
## 
##     Null deviance: 445.82335  on 7  degrees of freedom
## Residual deviance:   0.30072  on 1  degrees of freedom
## AIC: 59.683
## 
## Number of Fisher Scoring iterations: 4
##chisquare table
qchisq(0.05,1,lower.tail=FALSE)
## [1] 3.841459
##=====================## 
#Menguji interaksi YZ
#Model 3: Interaksi XY XZ (Interaksi GI,HI)
##=====================##
#Conditional Association on X (tanpa YZ/GH)
model3<-glm(counts~x.IO+y.HO+z.gender+x.IO*y.HO+x.IO*z.gender,            
            family=poisson("link"=log)) 
summary(model3)
## 
## Call:
## glm(formula = counts ~ x.IO + y.HO + z.gender + x.IO * y.HO + 
##     x.IO * z.gender, family = poisson(link = log))
## 
## Deviance Residuals: 
##        1         2         3         4         5         6         7         8  
## -0.93493   0.67971   0.05945  -0.02883   0.81131  -0.61817  -0.04336   0.02087  
## 
## Coefficients:
##                           Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                 3.8682     0.1398  27.675  < 2e-16 ***
## x.IO1support                1.3759     0.1548   8.886  < 2e-16 ***
## y.HO1support               -1.4572     0.2693  -5.411 6.26e-08 ***
## z.gender1M                 -0.6436     0.2218  -2.901  0.00372 ** 
## x.IO1support:y.HO1support   0.8724     0.2841   3.071  0.00214 ** 
## x.IO1support:z.gender1M     0.4204     0.2384   1.763  0.07782 .  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for poisson family taken to be 1)
## 
##     Null deviance: 445.8233  on 7  degrees of freedom
## Residual deviance:   2.3831  on 2  degrees of freedom
## AIC: 59.765
## 
## Number of Fisher Scoring iterations: 3
##chisquare table
qchisq(0.05,1,lower.tail=FALSE)
## [1] 3.841459
##=====================## 
#Menguji interaksi XZ
#Model 4: Interaksi XY YZ (Interaksi GH,HI)
##=====================## 
#Conditional Association on Y (tanpa XZ/GI)
model4<-glm(counts~x.IO+y.HO+z.gender+x.IO*y.HO+y.HO*z.gender,              
            family=poisson("link"=log)) 
summary(model4)
## 
## Call:
## glm(formula = counts ~ x.IO + y.HO + z.gender + x.IO * y.HO + 
##     y.HO * z.gender, family = poisson(link = log))
## 
## Deviance Residuals: 
##        1         2         3         4         5         6         7         8  
##  0.08450   0.61232  -0.28835  -1.39207  -0.06863  -0.55869   0.22653   1.16424  
## 
## Coefficients:
##                           Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                3.69832    0.12510  29.563  < 2e-16 ***
## x.IO1support               1.54142    0.12896  11.953  < 2e-16 ***
## y.HO1support              -1.36951    0.27864  -4.915 8.88e-07 ***
## z.gender1M                -0.21337    0.09885  -2.158  0.03090 *  
## x.IO1support:y.HO1support  0.87239    0.28411   3.071  0.00214 ** 
## y.HO1support:z.gender1M   -0.20823    0.17311  -1.203  0.22903    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for poisson family taken to be 1)
## 
##     Null deviance: 445.8233  on 7  degrees of freedom
## Residual deviance:   4.1267  on 2  degrees of freedom
## AIC: 61.509
## 
## Number of Fisher Scoring iterations: 4
##chisquare table
qchisq(0.05,1,lower.tail=FALSE)
## [1] 3.841459
##=====================## 
#Menguji interaksi XY
#Model 5: Interaksi XZ YZ (Interaksi GH,GI)
##=====================##
#Conditional Association on Z (tanpa XY/HI)
model5<-glm(counts~x.IO+y.HO+z.gender+x.IO*z.gender+y.HO*z.gender,            
            family=poisson("link"=log))
summary(model5)
## 
## Call:
## glm(formula = counts ~ x.IO + y.HO + z.gender + x.IO * z.gender + 
##     y.HO * z.gender, family = poisson(link = log))
## 
## Deviance Residuals: 
##       1        2        3        4        5        6        7        8  
##  0.4103  -0.2763  -1.2251   0.7402   0.9489  -0.7181  -2.3699   1.5298  
## 
## Coefficients:
##                         Estimate Std. Error z value Pr(>|z|)    
## (Intercept)               3.6420     0.1360  26.783  < 2e-16 ***
## x.IO1support              1.6094     0.1426  11.285  < 2e-16 ***
## y.HO1support             -0.6054     0.1112  -5.444 5.21e-08 ***
## z.gender1M               -0.5749     0.2289  -2.511   0.0120 *  
## x.IO1support:z.gender1M   0.4204     0.2384   1.763   0.0778 .  
## y.HO1support:z.gender1M  -0.2082     0.1731  -1.203   0.2290    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for poisson family taken to be 1)
## 
##     Null deviance: 445.823  on 7  degrees of freedom
## Residual deviance:  11.666  on 2  degrees of freedom
## AIC: 69.048
## 
## Number of Fisher Scoring iterations: 4
##chisquare table
qchisq(0.05,1,lower.tail=FALSE)
## [1] 3.841459

For model (GH, GI, HI) berarti mengacu pada model homogenous.

##=====================## 
#Model 2: Interaksi XY XZ YZ (Interaksi GH,GI,HI)
##=====================## 
#Homogenous Model  
model2 <- glm(counts~x.IO+y.HO+z.gender+x.IO*y.HO+x.IO*z.gender+ y.HO*z.gender,              
              family=poisson("link"=log))
summary(model2)
## 
## Call:
## glm(formula = counts ~ x.IO + y.HO + z.gender + x.IO * y.HO + 
##     x.IO * z.gender + y.HO * z.gender, family = poisson(link = log))
## 
## Deviance Residuals: 
##        1         2         3         4         5         6         7         8  
## -0.10362   0.07183   0.39073  -0.17923   0.08516  -0.06730  -0.26626   0.13173  
## 
## Coefficients:
##                           Estimate Std. Error z value Pr(>|z|)    
## (Intercept)                 3.8521     0.1415  27.219  < 2e-16 ***
## x.IO1support                1.3514     0.1575   8.578  < 2e-16 ***
## y.HO1support               -1.3750     0.2750  -5.001 5.71e-07 ***
## z.gender1M                 -0.5976     0.2242  -2.666  0.00768 ** 
## x.IO1support:y.HO1support   0.8997     0.2852   3.155  0.00160 ** 
## x.IO1support:z.gender1M     0.4636     0.2406   1.927  0.05401 .  
## y.HO1support:z.gender1M    -0.2516     0.1749  -1.438  0.15035    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## (Dispersion parameter for poisson family taken to be 1)
## 
##     Null deviance: 445.82335  on 7  degrees of freedom
## Residual deviance:   0.30072  on 1  degrees of freedom
## AIC: 59.683
## 
## Number of Fisher Scoring iterations: 4