526
Le logiciel R - Effectuer des analyses statistiques
> step(lm(BWT∼1),BWT∼LWT+AGE+UI+SMOKE+HT+FVT1+PTL1,
+
direction="both")
Start: AIC=2492.66
BWT ∼ 1
Df Sum of Sq
RSS
AIC
+ UI
1
8028747 91888305 2478.8
+ PTL1
1
4757523 95159530 2485.4
+ SMOKE 1
3573406 96343646 2487.8
+ LWT
1
3448881 96468171 2488.0
+ HT
1
2132014 97785038 2490.6
+ FVT1
1
1338322 98578731 2492.1

99917053 2492.7
+ AGE
1
806927 99110126 2493.1
Step: AIC=2478.83
BWT ∼ UI
Df Sum of Sq
RSS
AIC
+ HT
1
3162469 88725836 2474.2
+ SMOKE 1
2949940 88938365 2474.7
+ PTL1
1
2837049 89051257 2474.9
+ LWT
1
2076990 89811315 2476.5

91888305 2478.8
+ FVT1
1
949028 90939278 2478.9
+ AGE
1
472355 91415950 2479.9
- UI
1
8028747 99917053 2492.7
Step: AIC=2474.21
BWT ∼ UI + HT
Df Sum of Sq
RSS
AIC
+ LWT
1
3560080 85165756 2468.5
+ SMOKE 1
2828310 85897527 2470.1
+ PTL1
1
2682800 86043036 2470.4

88725836 2474.2
+ FVT1
1
698035 88027801 2474.7
+ AGE
1
415275 88310561 2475.3
- HT
1
3162469 91888305 2478.8
- UI
1
9059202 97785038 2490.6
Step: AIC=2468.47
BWT ∼ UI + HT + LWT
Df Sum of Sq
RSS
AIC
+ SMOKE 1
2579898 82585858 2464.7
+ PTL1
1
2127921 83037835 2465.7

85165756 2468.5
+ FVT1
1
509265 84656491 2469.3
+ AGE
1
94703 85071053 2470.3
- LWT
1
3560080 88725836 2474.2
- HT
1
4645559 89811315 2476.5
- UI
1
7482463 92648219 2482.4
Step: AIC=2464.66
BWT ∼ UI + HT + LWT + SMOKE
Df Sum of Sq
RSS
AIC