Responsi 7 STA1543-Analisis Data Kategorik

2022-09-20

Minggu ke-7 Bagian 2 ini akan membahas mengenai: Penerapan Regresi Logistik Multinomial

Pendahuluan

Regresi logistik multinomial digunakan untuk memodelkan hubungan antara peubah respon lebih dari dua kategori dengan satu atau lebih peubah penjelas. Peubah penjelasnya bisa berupa data kontinu atau kategorik. Peubah responnya berskala nominal (tidak ada tingkatan).

Soal 1

setwd("C:\\Users\\ACER\\Downloads\\")

Jawaban Soal 1

Input Data

size <- factor(rep(c("<=2.3",">2.3"),40))
food <-factor(rep(c("Fish","Inver","Rept","Bird","Other"),rep(16,5)))
gender<-rep(factor(rep(c("Male","Female"),rep(2,2))),20)
lake<-rep(factor(rep(c("Han","Okl","Tra","Geo"),rep(4,4))),5)
counts<-c(7,4,16,3,2,13,3,0,3,8,2,0,13,9,3,8,1,0,3,0,2,7,9,1,7,6,4,1,10,0,9,1,0,0,2,1,0,6,1,0,1,6,1,0,0,0,1,0,0,1,2,2,0,0,0,1,0,3,1,0,2,1,0,0,5,2,3,3,1,0,2,0,1,5,4,0,2,2,1,1)

Penentuan Referensi

size <- relevel(size, ref=">2.3")
food <- relevel(food, ref="Fish")
gender <- relevel(gender, ref="Female")
lake <- relevel(lake, ref="Geo")
makan <- data.frame(lake, gender, size, food, counts)
datafood <- makan[rep(row.names(makan),counts),1:4]
head(datafood)
##     lake gender  size food
## 1    Han   Male <=2.3 Fish
## 1.1  Han   Male <=2.3 Fish
## 1.2  Han   Male <=2.3 Fish
## 1.3  Han   Male <=2.3 Fish
## 1.4  Han   Male <=2.3 Fish
## 1.5  Han   Male <=2.3 Fish
dim(datafood)
## [1] 219   4

Bagian A

library(foreign)
library(nnet)
model_1 <- multinom(food ~ lake + size, data=datafood)
## # weights:  30 (20 variable)
## initial  value 352.466903 
## iter  10 value 271.607785
## iter  20 value 270.046051
## final  value 270.040140 
## converged
summary(model_1)
## Call:
## multinom(formula = food ~ lake + size, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan      lakeOkl  lakeTra  size<=2.3
## Bird    -2.093358  0.6954256 -0.652622721 1.088098 -0.6306329
## Inver   -1.549021 -1.6581178  0.937237973 1.122002  1.4581457
## Other   -1.904343  0.8263115  0.005792737 1.516461  0.3315514
## Rept    -3.314512  1.2428408  2.458913302 2.935262 -0.3512702
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3
## Bird    0.6622972 0.7813123 1.2020025 0.8417085 0.6424863
## Inver   0.4249185 0.6128466 0.4719035 0.4905122 0.3959418
## Other   0.5258313 0.5575446 0.7765655 0.6214371 0.4482504
## Rept    1.0530577 1.1854031 1.1181000 1.1163844 0.5800207
## 
## Residual Deviance: 540.0803 
## AIC: 580.0803
exp(summary(model_1)$coefficients)
##       (Intercept)   lakeHan    lakeOkl   lakeTra size<=2.3
## Bird   0.12327247 2.0045620  0.5206784  2.968624 0.5322548
## Inver  0.21245592 0.1904972  2.5529204  3.070995 4.2979825
## Other  0.14892051 2.2848753  1.0058095  4.556075 1.3931278
## Rept   0.03635178 3.4654441 11.6920989 18.826431 0.7037936

Persamaan prediksi odds dimana alligator memilih memakan bird dibandingkan dengan fish adalah:

\[log\left ( \frac{\widehat{\pi }_B}{\widehat{\pi }_F} \right )=-2.09-0.63sz+0.7lk_H-0.65lk_O+1.09lk_T\]

Interpretasi:

  1. \(e^{−2.09}= 0.123\)

Untuk alligator berukuran > 2.3 m di Lake George, odds alligator memakan bird dibandingkan alligator memakan fish adalah 0.123.

  1. \(e{−0.63}= 0.532\)

Untuk alligator berukuran ≤ 2.3 m, odds alligator memakan bird dibandingkan fish adalah 0.532 kalinya odds alligator beukuran > 2.3 m.

  1. \(e^{0.7}= 2.005\)

Untuk alligator di Lake Hancock, odds alligator memakan bird dibandingkan fish adalah 2.005 kalinya odds alligator di Lake George.

  1. \(e^{−0.65}= 0.521\)

Untuk alligator di Lake Oklawaha, odds alligator memakan bird dibandingkan fish adalah 0.521 kalinya odds alligator di Lake George.

  1. \(e^{1.09}= 2.97\)

Untuk alligator di Lake Trafford, odds alligator memakan bird dibandingkan fish adalah 2.97 kalinya odds alligator di Lake George.

Persamaan prediksi odds dimana alligator memilih memakan invertebrata dibandingkan dengan fish adalah:

\[log\left ( \frac{\widehat{\pi }_I}{\widehat{\pi }_F} \right )=-1.55+1.46sz-1.66lk_H+0.94lk_O+1.12lk_T\]

Interpretasi:

  1. \(e^{-1.55}= 0.21\)

Untuk alligator berukuran > 2.3 m di Lake George, odds alligator memakan invertebrata dibandingkan fish adalah 0.21.

  1. \(e^{1.46}= 4.3\)

Untuk alligator berukuran ≤ 2.3 m, odds alligator memakan invertebrata dibandingkan fish adalah 4.3 kalinya odds alligator beukuran > 2.3 m.

  1. \(e^{−1.66= 0.19\)

Untuk alligator di Lake Hancock, odds alligator memakan invertebrata dibandingkan fish adalah 0.19 kalinya odds alligator di Lake George.

  1. \(e^{0.94= 2.55\)

Untuk alligator di Lake Oklawaha, odds alligator memakan invertebrata dibandingkan fish adalah 2.55 kalinya odds alligator di Lake George.

  1. \(e^{1.12}= 3.07\)

Untuk alligator di Lake Trafford, odds alligator memakan invertebrata dibandingkan fish adalah 3.07 kalinya odds alligator di Lake George.

Persamaan prediksi odds dimana alligator memilih memakan others dibandingkan dengan fish adalah:

\[log\left ( \frac{\widehat{\pi }_O}{\widehat{\pi }_F} \right )=-1.9+0.33sz+0.83lk_H+0.01lk_O+1.52lk_T\]

Interpretasi:

  1. \(e^{−1.9}= 0.15\)

Untuk alligator berukuran > 2.3 m di Lake George, odds alligator memakan others dibandingkan fish adalah 0.15.

  1. \(e^{0.33}= 1.39\)

Untuk alligator berukuran ≤ 2.3 m, odds alligator memakan others dibandingkan fish adalah 1.39 kalinya odds alligator beukuran > 2.3 m.

  1. \(e^{0.83}= 2.28\)

Untuk alligator di Lake Hancock, odds alligator memakan others dibandingkan fish adalah 2.28 kalinya odds alligator di Lake George.

  1. \(e^{0.01}= 1.01\)

Untuk alligator di Lake Oklawaha, odds alligator memakan others dibandingkan fish adalah 1.01 kalinya odds alligator di Lake George.

  1. \(e^{1.52}= 4.56\)

Untuk alligator di Lake Trafford, odds alligator memakan others dibandingkan fish adalah 4.56 kalinya odds alligator di Lake George.

Persamaan prediksi odds dimana alligator memilih memakan reptile dibandingkan dengan fish adalah:

\[log\left ( \frac{\widehat{\pi }_R}{\widehat{\pi }_F} \right )=-3.31-0.35z+1.24lk_H+2.46lk_O+2.94lk_T\]

Interpretasi:

  1. \(e^{−3.31}= 0.036\)

Untuk alligator berukuran > 2.3 m di Lake George, odds alligator memakan reptile dibandingkan fish adalah 0.036.

  1. \(e^{−0.35}= 0.7\)

Untuk alligator berukuran ≤ 2.3 m, odds alligator memakan reptile dibandingkan fish adalah 0.7 kalinya odds alligator beukuran > 2.3 m.

  1. \(e^{1.24}= 3.47\)

Untuk alligator di Lake Hancock, odds alligator memakan reptile dibandingkan fish adalah 3.47 kalinya odds alligator di Lake George.

  1. \(e^{2.46}= 11.7\)

Untuk alligator di Lake Oklawaha, odds alligator memakan reptile dibandingkan fish adalah 11.7 kalinya odds alligator di Lake George.

  1. \(e^{2.94}= 18.83\)

Untuk alligator di Lake Trafford, odds alligator memakan reptile dibandingkan fish adalah 18.83 kalinya odds alligator di Lake George.

Bagian B

model_2 <- multinom(food ~ lake + size + gender, data=datafood)
## # weights:  35 (24 variable)
## initial  value 352.466903 
## iter  10 value 270.967533
## iter  20 value 268.934907
## final  value 268.932740 
## converged
summary(model_2)
## Call:
## multinom(formula = food ~ lake + size + gender, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan     lakeOkl  lakeTra  size<=2.3 genderMale
## Bird    -1.701750  0.5751767 -0.55073594 1.236877 -0.7302898 -0.6064571
## Inver   -1.167210 -1.7805263  0.91314471 1.155786  1.3362563 -0.4629756
## Other   -1.721273  0.7665622  0.02600333 1.557716  0.2905663 -0.2525879
## Rept    -2.858940  1.1294537  2.53024455 3.061047 -0.5570885 -0.6276206
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird    0.7690488 0.7952037 1.2099728 0.8660879 0.6522819  0.6888490
## Inver   0.5337511 0.6232106 0.4761165 0.4927850 0.4111930  0.3955225
## Other   0.6313811 0.5685499 0.7777727 0.6256727 0.4599253  0.4663465
## Rept    1.1456331 1.1928006 1.1221172 1.1297303 0.6466081  0.6852751
## 
## Residual Deviance: 537.8655 
## AIC: 585.8655
abs(model_1$edf-model_2$edf)
## [1] 4
qchisq(0.05, 4, lower.tail=FALSE)
## [1] 9.487729
  1. Hipotesis:

\(H_0\): peubah gender tidak berpengaruh nyata terhadap perbedaan odds bagi semua tive makanan utama alligator

\(H_1\): peubah gender berpengaruh nyata terhadap perbedaan odds bagi semua tive makanan utama alligator

  1. Taraf Signifikan

\(\alpha=5\%\)

  1. Statistik Uji

\(\bigtriangleup Deviance=540.0803-537.8655=2.2148\)

  1. RR

Tolak \(H_0\) jika \(\bigtriangleup Deviance > \chi ^{2}_{0.05,4}\)

  1. Keputusan

Karena 2.2148<9.49, maka gagal tolak \(H_0\)

  1. Kesimpulan

Dengan taraf nyata \(5\%\) tidak ada cukup bukti untuk mengatakan bahwa gender berpengaruh nyata terhadap perbedaan odds bagi semua tive makanan utama alligator

model_3 <- multinom(food ~ lake + gender, data=datafood)
## # weights:  30 (20 variable)
## initial  value 352.466903 
## iter  10 value 279.421076
## iter  20 value 277.733691
## final  value 277.732884 
## converged
summary(model_3)
## Call:
## multinom(formula = food ~ lake + gender, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan     lakeOkl   lakeTra genderMale
## Bird  -2.12320607  0.4818741 -0.47393004 1.2811363 -0.4245404
## Inver  0.01048504 -1.7605713  0.59314476 0.9609816 -0.8577619
## Other -1.51431307  0.7842964 -0.07500933 1.4829188 -0.2871253
## Rept  -3.37256725  1.1400408  2.55949903 3.0361432 -0.1834060
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra genderMale
## Bird    0.7212115 0.7960695 1.1922056 0.8381776  0.6476502
## Inver   0.3584792 0.6187324 0.4425069 0.4722548  0.3694164
## Other   0.5318941 0.5701319 0.7661014 0.6158038  0.4542938
## Rept    1.0863463 1.1945082 1.1088625 1.1134113  0.5873043
## 
## Residual Deviance: 555.4658 
## AIC: 595.4658
abs(model_3$edf-model_2$edf)
## [1] 4
qchisq(0.05, 4, lower.tail=FALSE)
## [1] 9.487729
  1. Hipotesis:

\(H_0\): peubah size tidak berpengaruh nyata terhadap perbedaan odds bagi semua tive makanan utama alligator

\(H_1\): peubah size berpengaruh nyata terhadap perbedaan odds bagi semua tive makanan utama alligator

  1. Taraf Signifikan

\(\alpha=5\%\)

  1. Statistik Uji

\(\bigtriangleup Deviance=555.4658-537.8655=17.6003\)

  1. RR

Tolak \(H_0\) jika \(\bigtriangleup Deviance > \chi ^{2}_{0.05,4}\)

  1. Keputusan

Karena 17.6003>9.49, maka tolak \(H_0\)

  1. Kesimpulan

Dengan taraf nyata \(5\%\) ada cukup bukti untuk mengatakan bahwa size berpengaruh nyata terhadap perbedaan odds bagi semua tive makanan utama alligator

model_4 <- multinom(food ~ size + gender, data=datafood)
## # weights:  20 (12 variable)
## initial  value 352.466903 
## iter  10 value 294.669539
## final  value 294.091727 
## converged
summary(model_4)
## Call:
## multinom(formula = food ~ size + gender, data = datafood)
## 
## Coefficients:
##       (Intercept)  size<=2.3  genderMale
## Bird   -1.2790620 -0.7533726 -0.61466393
## Inver  -0.9638861  0.9210878 -0.09004848
## Other  -1.0905582  0.2328891 -0.19634008
## Rept   -1.2170166 -0.8681379 -0.03140815
## 
## Std. Errors:
##       (Intercept) size<=2.3 genderMale
## Bird    0.5806349 0.6439387  0.6337949
## Inver   0.4001729 0.3730328  0.3538182
## Other   0.4584432 0.4373966  0.4378935
## Rept    0.5455407 0.5629537  0.5693974
## 
## Residual Deviance: 588.1835 
## AIC: 612.1835
abs(model_4$edf-model_2$edf)
## [1] 12
qchisq(0.05, 12, lower.tail=FALSE)
## [1] 21.02607
  1. Hipotesis:

\(H_0\): peubah lake tidak berpengaruh nyata terhadap perbedaan odds bagi semua tipe makanan utama alligator

\(H_1\): peubah lake berpengaruh nyata terhadap perbedaan odds bagi semua tipe makanan utama alligator

  1. Taraf Signifikan

\(\alpha=5\%\)

  1. Statistik Uji

\(\bigtriangleup Deviance=588.1835-537.8655=50.318\)

  1. RR

Tolak \(H_0\) jika \(\bigtriangleup Deviance > \chi ^{2}_{0.05,4}\)

  1. Keputusan

Karena 50.3183>21.03, maka tolak \(H_0\)

  1. Kesimpulan

Dengan taraf nyata \(5\%\) ada cukup bukti untuk mengatakan bahwa lake berpengaruh nyata terhadap perbedaan odds bagi semua tive makanan utama alligator

Jadi, berdasarkan hasil pengujian di atas dapat disimpulkan bahwa peubah yang berpengaruh nyata terhadap tipe makanan utama Alligator adalah peubah Lake dan peubah Size.

Bagian C

new=data.frame(size=as.factor("<=2.3"),gender=as.factor("Male"),lake=as.factor("Tra"))
#model2
predict(model_2,newdata=new,"probs") 
##       Fish       Bird      Inver      Other       Rept 
## 0.20881597 0.03446118 0.49438276 0.18417282 0.07816727

Berdasarkan output dari program R peluang yang paling besar adalah aliigator tersebut akan memakan Invertebrata.

Bagian D

model_1c1 <- multinom(food ~ lake,data=datafood)
## # weights:  25 (16 variable)
## initial  value 352.466903 
## iter  10 value 281.030560
## iter  20 value 280.583926
## final  value 280.583844 
## converged
summary(model_1c1)
## Call:
## multinom(formula = food ~ lake, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan     lakeOkl   lakeTra
## Bird   -2.3982809  0.6065505 -0.49188808 1.2197770
## Inver  -0.5008393 -1.5137909  0.55488981 0.8263598
## Other  -1.7048477  0.8686390 -0.08689071 1.4425750
## Rept   -3.4962205  1.1937161  2.55175319 3.0107928
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra
## Bird    0.6031161 0.7727128 1.1912598 0.8310587
## Inver   0.2833774 0.6029744 0.4341550 0.4612870
## Other   0.4438217 0.5542879 0.7654142 0.6114775
## Rept    1.0148749 1.1817886 1.1083250 1.1099095
## 
## Residual Deviance: 561.1677 
## AIC: 593.1677
model_1c2 <- multinom(food ~ size,data=datafood)
## # weights:  15 (8 variable)
## initial  value 352.466903 
## iter  10 value 294.670879
## final  value 294.606678 
## converged
summary(model_1c2)
## Call:
## multinom(formula = food ~ size, data = datafood)
## 
## Coefficients:
##       (Intercept)  size<=2.3
## Bird    -1.727214 -0.5551882
## Inver   -1.034070  0.9489120
## Other   -1.241709  0.2943162
## Rept    -1.241705 -0.8583649
## 
## Std. Errors:
##       (Intercept) size<=2.3
## Bird    0.3836949 0.6063277
## Inver   0.2910708 0.3568648
## Other   0.3148735 0.4149523
## Rept    0.3148729 0.5349960
## 
## Residual Deviance: 589.2134 
## AIC: 605.2134
model_1c3 <- multinom(food ~ gender,data=datafood)
## # weights:  15 (8 variable)
## initial  value 352.466903 
## iter  10 value 301.192714
## final  value 301.129428 
## converged
summary(model_1c3)
## Call:
## multinom(formula = food ~ gender, data = datafood)
## 
## Coefficients:
##       (Intercept) genderMale
## Bird   -1.7635851 -0.3680370
## Inver  -0.2231478 -0.3578812
## Other  -0.9162928 -0.2708745
## Rept   -1.7635569  0.2509570
## 
## Std. Errors:
##       (Intercept) genderMale
## Bird    0.4418570  0.5958549
## Inver   0.2535467  0.3339731
## Other   0.3162281  0.4153372
## Rept    0.4418517  0.5376858
## 
## Residual Deviance: 602.2589 
## AIC: 618.2589
model_1c4 <- multinom(food ~ lake +size + gender + lake*size, 
data=datafood)
## # weights:  50 (36 variable)
## initial  value 352.466903 
## iter  10 value 265.274636
## iter  20 value 260.069949
## iter  30 value 258.937775
## iter  40 value 258.824166
## iter  50 value 258.819006
## final  value 258.818962 
## converged
summary(model_1c4)
## Warning in sqrt(diag(vc)): NaNs produced
## Call:
## multinom(formula = food ~ lake + size + gender + lake * size, 
##     data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan     lakeOkl   lakeTra   size<=2.3  genderMale
## Bird    -2.442347   1.928711   0.6706186  2.282905  0.92900200 -0.84648228
## Inver   -2.453306 -12.256978   2.7331906  3.111918  3.17363446 -0.81592590
## Other   -1.688556   1.392344 -26.0432791  1.299438  0.07643898 -0.08264057
## Rept   -28.472136  26.922121  28.6961637 29.221745 26.38883928 -1.07334267
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3
## Bird         -2.6180164        -37.538905        -1.9359701
## Inver        10.0209021         -2.448568        -2.6137822
## Other        -0.8062165         27.172630         0.3637365
## Rept        -26.9993336        -27.961392       -27.5229971
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird    1.0695771 1.2468205 1.5193189 1.3106646 1.2892933  0.7430086
## Inver   1.0470055 0.3370560 1.1530087 1.1841238 1.0964497  0.4448919
## Other   0.6785145 0.8580021 0.4916661 0.8711876 0.8925871  0.4749617
## Rept    0.8453331 1.0511858 0.7479391 0.7710755 0.6558217  0.7692781
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3
## Bird          1.6535383               NaN          1.897784
## Inver         0.3370534         1.3660324          1.361887
## Other         1.1500995         0.4916661          1.258627
## Rept          1.1866462         1.2780398          1.085509
## 
## Residual Deviance: 517.6379 
## AIC: 589.6379
model_1c5 <- multinom(food ~ lake +size + gender +lake*gender,
data=datafood)
## # weights:  50 (36 variable)
## initial  value 352.466903 
## iter  10 value 265.296842
## iter  20 value 259.530895
## iter  30 value 258.505815
## iter  40 value 258.481781
## iter  50 value 258.481314
## iter  50 value 258.481312
## iter  50 value 258.481312
## final  value 258.481312 
## converged
summary(model_1c5)
## Call:
## multinom(formula = food ~ lake + size + gender + lake * gender, 
##     data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan    lakeOkl    lakeTra  size<=2.3   genderMale
## Bird   -16.263542 15.4631991 16.0110863 16.5768526 -1.1908325  14.87784409
## Inver   -1.046837 -2.1160620  0.8808395  0.5136922  1.5215173  -0.94732194
## Other   -1.681967  0.5689054  1.3192386  2.4229579 -0.0522542   0.01106523
## Rept    -2.318943  0.6134287  1.3720043  1.7963644 -0.1881737 -14.50610070
##       lakeHan:genderMale lakeOkl:genderMale lakeTra:genderMale
## Bird         -15.8646026        -33.5355368         -16.335073
## Inver          0.5034982          0.3048162           1.093681
## Other          0.6840401         -2.3514491          -1.347638
## Rept          -7.7570090         14.5535117          14.612770
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird    0.6627872 0.6452407 1.1230758 0.9794898 0.6863823  0.5932994
## Inver   0.5534699 0.7863163 0.8191284 0.9686761 0.4618276  0.6126551
## Other   0.7978770 0.9140771 1.2081530 1.1815357 0.4926099  0.9471840
## Rept    1.0821756 1.2371499 1.5813617 1.6465079 0.6981059  0.6905281
##       lakeHan:genderMale lakeOkl:genderMale lakeTra:genderMale
## Bird        1.124843e+00       2.393237e-07          1.1965529
## Inver       1.369324e+00       1.085099e+00          1.1800008
## Other       1.167883e+00       1.731244e+00          1.4487918
## Rept        9.243461e-10       9.573608e-01          0.9861938
## 
## Residual Deviance: 516.9626 
## AIC: 588.9626
model_1c6 <- multinom(food ~ lake + size + gender +size*gender,data=datafood)
## # weights:  40 (28 variable)
## initial  value 352.466903 
## iter  10 value 269.657367
## iter  20 value 267.859275
## iter  30 value 267.849421
## iter  30 value 267.849420
## iter  30 value 267.849420
## final  value 267.849420 
## converged
summary(model_1c6)
## Call:
## multinom(formula = food ~ lake + size + gender + size * gender, 
##     data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan    lakeOkl  lakeTra  size<=2.3 genderMale
## Bird    -1.610300  0.6067870 -0.4587223 1.325001 -0.9499501 -0.8219859
## Inver   -1.101382 -1.7722719  0.9424647 1.184062  1.2416008 -0.5742209
## Other   -1.485725  0.8147021  0.1679189 1.684913 -0.1051924 -0.6960225
## Rept    -3.339082  0.9879282  2.2335485 2.778320  0.3511508  0.2037592
##       size<=2.3:genderMale
## Bird             0.4491087
## Inver            0.1497835
## Other            0.6635604
## Rept            -1.6862430
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird    0.8007333 0.8014123 1.2462166 0.9110709 0.9163585  0.9299201
## Inver   0.6924399 0.6288826 0.5021787 0.5131789 0.7569443  0.7911095
## Other   0.6865768 0.5726299 0.8064032 0.6559994 0.7136479  0.7714181
## Rept    1.3673993 1.2035947 1.1455785 1.1486470 1.1892358  1.1845946
##       size<=2.3:genderMale
## Bird             1.3372394
## Inver            0.9344216
## Other            0.9506783
## Rept             1.6487195
## 
## Residual Deviance: 535.6988 
## AIC: 591.6988
model_1c7 <-multinom(food~lake+size+gender+lake*size+lake*gender, data=datafood)
## # weights:  65 (48 variable)
## initial  value 352.466903 
## iter  10 value 263.550767
## iter  20 value 252.470318
## iter  30 value 249.416728
## iter  40 value 249.182771
## iter  50 value 249.171406
## iter  60 value 249.171094
## final  value 249.171077 
## converged
summary(model_1c7)
## Warning in sqrt(diag(vc)): NaNs produced
## Call:
## multinom(formula = food ~ lake + size + gender + lake * size + 
##     lake * gender, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan    lakeOkl   lakeTra   size<=2.3   genderMale
## Bird   -26.545198  26.052061  28.139480 27.156201  0.35746095  24.32889436
## Inver   -2.325022 -11.825325   3.343036  2.464092  3.39642459  -1.34474341
## Other   -1.723879   1.046963 -24.458241  2.707398  0.06578482  -0.01984412
## Rept   -23.134727  21.806167  23.280548 23.102673 21.98323898 -20.17051634
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3 lakeHan:genderMale
## Bird         -2.0599485         -41.07881        -1.8707416        -25.3707049
## Inver         9.1294547          -3.19803        -2.5823130          0.9185007
## Other        -0.7054789          25.78133        -0.3803866          0.6513613
## Rept        -22.6845546         -23.42510       -22.7124870         -6.5400092
##       lakeOkl:genderMale lakeTra:genderMale
## Bird         -49.7462758         -25.988068
## Inver         -0.2158311           1.066904
## Other         -0.4355696          -1.489857
## Rept          19.2273535          19.910052
## 
## Std. Errors:
##       (Intercept)    lakeHan   lakeOkl  lakeTra size<=2.3 genderMale
## Bird    0.7760831   0.958557 1.6265326 1.492307 1.2943109  0.8719357
## Inver   1.0551636 487.518218 1.5826690 1.569481 1.1416983  0.7209299
## Other   0.8169634   1.077639 0.6805341 1.564129 0.9248934  0.9809570
## Rept    0.8301478   1.142391 1.6281559 1.528664 0.8301478  0.8056223
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3 lakeHan:genderMale
## Bird           1.653312               NaN          2.189651       1.305838e+00
## Inver        487.518527         1.5483507          1.422054       1.423678e+00
## Other          1.175912         0.6805341          1.434644       1.195075e+00
## Rept           1.309035         1.5503497          1.188362       2.081841e-10
##       lakeOkl:genderMale lakeTra:genderMale
## Bird                 NaN           1.525571
## Inver           1.336203           1.281557
## Other           1.786260           1.589410
## Rept            1.339247           1.204804
## 
## Residual Deviance: 498.3422 
## AIC: 594.3422
model_1c8 <-multinom(food~lake+size+gender+lake*size+size*gender,data=datafood)
## # weights:  55 (40 variable)
## initial  value 352.466903 
## iter  10 value 264.007344
## iter  20 value 258.635097
## iter  30 value 257.471456
## iter  40 value 257.268765
## iter  50 value 257.260181
## iter  60 value 257.260007
## iter  60 value 257.260005
## iter  60 value 257.260005
## final  value 257.260005 
## converged
summary(model_1c8)
## Call:
## multinom(formula = food ~ lake + size + gender + lake * size + 
##     size * gender, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan     lakeOkl   lakeTra   size<=2.3  genderMale
## Bird    -2.374902   1.905770   0.7777711  2.380109  0.78737738 -1.00313562
## Inver   -2.089062 -12.450905   3.7710436  4.210933  2.65814738 -2.34599930
## Other   -1.684653   1.390753 -22.9574759  1.301454  0.04589109 -0.08759659
## Rept   -26.119021  24.440030  25.9644059 26.459374 24.29284507 -0.63691750
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3
## Bird         -2.5432412         -32.94969        -2.0141052
## Inver        10.3127719          -3.39441        -3.6750412
## Other        -0.7904554          24.10091         0.3663241
## Rept        -24.6885868         -25.43077       -24.8435013
##       size<=2.3:genderMale
## Bird            0.25393402
## Inver           1.75745447
## Other           0.03952345
## Rept           -1.13638396
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird    1.1116398 1.2505257 1.6186528 1.4283751  1.470820  1.1460683
## Inver   1.0663058 0.3359278 1.5774330 1.6200467  1.167156  1.3417232
## Other   0.7843509 0.8599831 0.4963547 0.9195573  1.090735  0.8394745
## Rept    1.1177932 1.0621017 0.9635959 0.9918237  1.145486  1.5602027
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3
## Bird          1.6767817      1.073912e-13          1.957890
## Inver         0.3359258      1.713893e+00          1.743582
## Other         1.1615493      4.963547e-01          1.283286
## Rept          1.2443446      1.359291e+00          1.229240
##       size<=2.3:genderMale
## Bird              1.533010
## Inver             1.425687
## Other             1.019876
## Rept              1.957142
## 
## Residual Deviance: 514.52 
## AIC: 594.52
model_1c9 <-multinom(food~lake+size+gender+lake*gender+size*gender,data=datafood)
## # weights:  55 (40 variable)
## initial  value 352.466903 
## iter  10 value 264.575413
## iter  20 value 258.989840
## iter  30 value 257.785301
## iter  40 value 257.722664
## iter  50 value 257.721130
## final  value 257.721117 
## converged
summary(model_1c9)
## Call:
## multinom(formula = food ~ lake + size + gender + lake * gender + 
##     size * gender, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan    lakeOkl    lakeTra  size<=2.3  genderMale
## Bird  -16.2454250 15.6026638 16.1814396 16.8103429 -1.4910019  14.7243894
## Inver  -0.9882986 -2.1039274  0.8933136  0.5292055  1.4356770  -0.9763839
## Other  -1.5457745  0.6835996  1.4561166  2.5972179 -0.3942057  -0.2679747
## Rept   -2.6795341  0.3888810  1.1089359  1.4747671  0.5445618 -13.0797407
##       lakeHan:genderMale lakeOkl:genderMale lakeTra:genderMale
## Bird         -16.0142292        -32.7287883         -16.454575
## Inver          0.5012999          0.2534458           1.043671
## Other          0.5702386         -2.3683123          -1.427343
## Rept          -6.8055922         13.7953320          13.964518
##       size<=2.3:genderMale
## Bird            0.60936071
## Inver           0.06734568
## Other           0.55921244
## Rept           -1.40622285
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird    0.7021724 0.6592361 1.1454332 1.0305022 0.9622487  0.7992739
## Inver   0.6928949 0.8027431 0.8333448 0.9877422 0.7899435  0.9277684
## Other   0.8223479 0.9407293 1.2384019 1.2313676 0.7728513  1.0714394
## Rept    1.2585713 1.2622550 1.6052792 1.6755239 1.2195085  0.9643344
##       lakeHan:genderMale lakeOkl:genderMale lakeTra:genderMale
## Bird        1.129073e+00       5.670007e-07           1.206149
## Inver       1.379981e+00       1.082868e+00           1.178162
## Other       1.189446e+00       1.736694e+00           1.464333
## Rept        3.891958e-09       1.001575e+00           1.058997
##       size<=2.3:genderMale
## Bird             1.3510612
## Inver            0.9707251
## Other            0.9933454
## Rept             1.6718032
## 
## Residual Deviance: 515.4422 
## AIC: 595.4422
model_1c10 <-multinom(food~lake+size+gender+lake*size+lake*gender+size*gender, data=datafood)
## # weights:  70 (52 variable)
## initial  value 352.466903 
## iter  10 value 261.806815
## iter  20 value 249.874155
## iter  30 value 245.251330
## iter  40 value 244.794341
## iter  50 value 244.772299
## iter  60 value 244.771293
## final  value 244.771286 
## converged
summary(model_1c10)
## Call:
## multinom(formula = food ~ lake + size + gender + lake * size + 
##     lake * gender + size * gender, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird   -29.680243  29.103199  68.77201 39.611336 13.866329  27.422556
## Inver   -2.006630 -14.493190  41.09846 40.176780  2.933473 -39.756994
## Other   -1.560861   1.181926 -38.81781  3.731800 -0.534904  -0.333421
## Rept   -34.044627  32.774394  21.58248  2.350668 32.774659 -14.981245
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3 lakeHan:genderMale
## Bird        -15.3329775         -79.63494        -24.490655        -28.0806124
## Inver        11.9281761         -40.92665        -40.410530          0.7598849
## Other        -0.5527564          40.50818         -0.942941          0.4179860
## Rept        -33.5480948         -21.41115         -1.774053        -14.3102392
##       lakeOkl:genderMale lakeTra:genderMale size<=2.3:genderMale
## Bird         -88.1781781         -38.334497          -13.4362543
## Inver          0.0461318           1.299149           38.6120194
## Other         -0.8036763          -2.307518            0.8491819
## Rept          26.6702270          46.387523          -31.8115065
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird    0.7070832 0.8084083 1.4658431 0.5917075 0.5509420  0.7777457
## Inver   1.0638255 0.4393419 1.0245550 1.2212504 1.2249471  0.9993125
## Other   0.8276239 1.0697093 0.7768042 2.0107535 1.2926849  1.0971195
## Rept    0.7485178 0.9206041 0.7360161 0.9455311 0.7553727  0.4517334
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3 lakeHan:genderMale
## Bird          0.8905558      5.432772e-11         0.7160007       1.237839e+00
## Inver         0.4393416      9.390471e-01         0.9931620       1.433917e+00
## Other         1.2294201      7.768042e-01         1.6393334       1.283608e+00
## Rept          1.0822488      9.218556e-01         0.8925133       4.926739e-13
##       lakeOkl:genderMale lakeTra:genderMale size<=2.3:genderMale
## Bird        3.296180e-08          0.8287452            1.0419266
## Inver       1.413217e+00          1.3337518            0.9072072
## Other       1.997547e+00          1.9339587            1.1962097
## Rept        4.255527e-01          0.5428352            0.9846263
## 
## Residual Deviance: 489.5426 
## AIC: 593.5426
model_1c11 <-multinom(food~lake+size+gender+lake*size+lake*gender+size*gender+lake*size*gender, data=datafood)
## # weights:  85 (64 variable)
## initial  value 352.466903 
## iter  10 value 260.145098
## iter  20 value 247.220833
## iter  30 value 244.162621
## iter  40 value 243.815027
## iter  50 value 243.801406
## iter  60 value 243.800899
## iter  60 value 243.800898
## iter  60 value 243.800898
## final  value 243.800898 
## converged
summary(model_1c11)
## Call:
## multinom(formula = food ~ lake + size + gender + lake * size + 
##     lake * gender + size * gender + lake * size * gender, data = datafood)
## 
## Coefficients:
##       (Intercept)    lakeHan    lakeOkl   lakeTra  size<=2.3 genderMale
## Bird   -23.659137  23.253776  45.302701 18.666966 -5.1636921  21.461986
## Inver   -2.079465 -12.135591  23.723299 41.083525  3.1778456 -32.399336
## Other   -2.079548   2.079581 -19.265751 -6.158001  0.9806851   0.575526
## Rept   -29.481972  28.383330   8.903792  8.739972 28.3828917  -9.045851
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3 lakeHan:genderMale
## Bird           3.489575        -44.628018          9.462975         -22.443051
## Inver          9.363311        -23.723138        -41.488498          -0.378315
## Other         -2.654656         19.959036          7.950245          -1.268768
## Rept         -29.363666         -8.903379         -8.333677         -13.270796
##       lakeOkl:genderMale lakeTra:genderMale size<=2.3:genderMale
## Bird           -68.65129         -17.450651             5.489023
## Inver           10.13646          -6.892404            31.038624
## Other          -14.17904           7.192033            -1.348468
## Rept            28.85082          29.500163           -21.726694
##       lakeHan:size<=2.3:genderMale lakeOkl:size<=2.3:genderMale
## Bird                    -29.234803                    0.4598397
## Inver                     1.466961                   -9.8742203
## Other                     3.379153                   14.6644729
## Rept                      4.422985                  -19.9036846
##       lakeTra:size<=2.3:genderMale
## Bird                   -44.1067826
## Inver                    8.4069123
## Other                   -8.2112240
## Rept                     0.8663284
## 
## Std. Errors:
##       (Intercept)   lakeHan   lakeOkl   lakeTra size<=2.3 genderMale
## Bird    0.7076713 0.8055881 1.2170267 0.5899784 0.5605073  0.7643122
## Inver   1.0606630 0.4583132 0.6686450 0.6394553 1.2527514  0.6124146
## Other   1.0607033 1.3385692 0.7359783 0.9350246 1.5679312  1.3176434
## Rept    0.7713307 0.9140028 0.7471843 0.8686971 0.7713308  0.4213413
##       lakeHan:size<=2.3 lakeOkl:size<=2.3 lakeTra:size<=2.3 lakeHan:genderMale
## Bird          0.9039139      9.842819e-12         0.7030400       1.229372e+00
## Inver         0.4583076      8.466216e-01         0.7271145       7.348490e-01
## Other         1.8764086      7.359783e-01         0.9350246       1.775630e+00
## Rept          1.0804467      9.296716e-01         0.9101667       9.906137e-10
##       lakeOkl:genderMale lakeTra:genderMale size<=2.3:genderMale
## Bird        4.851911e-10          0.8268938            1.0437480
## Inver       6.900638e-01          0.7756274            0.7546887
## Other       1.029998e+00          0.9350246            1.9095632
## Rept        4.222621e-01          0.4827984            0.5984610
##       lakeHan:size<=2.3:genderMale lakeOkl:size<=2.3:genderMale
## Bird                  9.598235e-11                 9.920193e-15
## Inver                 7.348490e-01                 9.390853e-01
## Other                 2.408691e+00                 1.029998e+00
## Rept                  9.081705e-18                 4.538504e-10
##       lakeTra:size<=2.3:genderMale
## Bird                  1.471557e-14
## Inver                 8.139676e-01
## Other                 1.352559e+00
## Rept                  5.984610e-01
## 
## Residual Deviance: 487.6018 
## AIC: 615.6018
model_1c1$deviance
## [1] 561.1677
model_1c2$deviance
## [1] 589.2134
model_1c3$deviance
## [1] 602.2589
model_1c4$deviance
## [1] 517.6379
model_1c5$deviance
## [1] 516.9626
model_1c6$deviance
## [1] 535.6988
model_1c7$deviance
## [1] 498.3422
model_1c8$deviance
## [1] 514.52
model_1c9$deviance
## [1] 515.4422
model_1c10$deviance
## [1] 489.5426
model_1c11$deviance
## [1] 487.6018
model_1c1$edf
## [1] 16
model_1c2$edf
## [1] 8
model_1c3$edf
## [1] 8
model_1c4$edf
## [1] 36
model_1c5$edf
## [1] 36
model_1c6$edf
## [1] 28
model_1c7$edf
## [1] 48
model_1c8$edf
## [1] 40
model_1c9$edf
## [1] 40
model_1c10$edf
## [1] 52
model_1c11$edf
## [1] 64
model_1c1$AIC
## [1] 593.1677
model_1c2$AIC
## [1] 605.2134
model_1c3$AIC
## [1] 618.2589
model_1c4$AIC
## [1] 589.6379
model_1c5$AIC
## [1] 588.9626
model_1c6$AIC
## [1] 591.6988
model_1c7$AIC
## [1] 594.3422
model_1c8$AIC
## [1] 594.52
model_1c9$AIC
## [1] 595.4422
model_1c10$AIC
## [1] 593.5426
model_1c11$AIC
## [1] 615.6018

Jadi, dapat disimpulkan bahwa model terbaik adalah model dengan peubah bebas size dan lake (Model 4). Hal ini juga dapat dipastikan dengan nilai AIC yang lebih kecil dibandingkan dengan model lainnya.