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--- r:dummy_variable [2023/06/07 07:59] – hkimscil
+++ r:dummy_variable [2023/06/07 08:49] (current) – [output] hkimscil
@@ Line 39: / Line 39: @@
 = 81-100
-pct (%) of emer (emergency) credentials: Some states will grant an emergency certificate or permit at the request of a school district that has posted and failed to find a qualified candidate for a teacher vacancy. It typically allows the candidate to serve in a temporary capacity for the duration of a school year.
+</code>
+  * pct (%) of emer (emergency) credentials: Some states will grant an emergency certificate or permit at the request of a school district that has posted and failed to find a qualified candidate for a teacher vacancy. It typically allows the candidate to serve in a temporary capacity for the duration of a school year.
+  * pct (%) of full credentials: To be fully certified, it generally means that a teacher must have graduated from an accredited college, completed an approved teacher credential program and passed a test of their academic skills.
-pct (%) of full credentials: To be fully certified, it generally means that a teacher must have graduated from an accredited college, completed an approved teacher credential program and passed a test of their academic skills.
-</code>
 위의 각각의 변인 yr_rnd 그리고 mealcat 을 독립변인으로 하고 종속변인을 api00 으로 하여 simple regression을 한다. 그리고 이후 이 둘을 모두 이용하여 multiple regression을 한다. 즉,
@@ Line 304: / Line 303: @@
 ^                 ^ mealcat0-46  ^ mealcat47-80   ^ mealcat81-100    ^
-| yr_rndbreak     | <wrap> yr_rndno_break = 0
+| yr_rndbreak     | <wrap> yr_rndbreak = 1
+yr_rndno_break = 0
+mealcat0-46 = 1
 mealcat47-80 = 0
 mealcat81-100 = 0 경우
 ''y hat = 808.013''
-</wrap>  | <wrap> yr_rndno_break = 0
+</wrap>  | <wrap> yr_rndbreak = 1
+yr_rndno_break = 0
 mealcat0-46 = 0
+mealcat47-80 = 1
 mealcat81-100 = 0 경우
-''y hat = 808.013 - 163.737 = 644.276''
+''**y hat = 808.013 - 163.737 = 644.276**''
-</wrap>  | <wrap> yr_rndno_break = 0
+</wrap>  | <wrap> yr_rndbreak = 1
+yr_rndno_break = 0
 mealcat0-46 = 0
-mealcat47-80 = 0 경우
+mealcat47-80 = 0
-''y hat = 808.013 - 281.683 = 526.33''
+mealcat81-100 = 1 경우
+''**y hat = 808.013 - 281.683 = 526.33**''
 </wrap>  |
 | yr_rndno_break  | <wrap> yr_rndbreak = 0
+yr_rndno_break = 1
+mealcat0-46 = 1
 mealcat47-80 = 0
 mealcat81-100 = 0 경우
-''y hat = 808.013 - 42.960 = 765.053''
+''**y hat = 808.013 - 42.960 = 765.053**''
 </wrap>  | <wrap> yr_rndbreak = 0
+yr_rndno_break = 1
 mealcat0-46 = 0
-mealcat81-100 = 0 경우
+mealcat47-80 = 1
-''y hat = 808.013 - 42.960 - 163.737 = 601.316''
+mealcat81-100 = 0 경우
-</wrap>  | <wrap> yr_rndbreak = 0
+''**y hat = 808.013 - 42.960 - 163.737 = 601.316**''
+</wrap>  | <wrap> yr_rndbreak = 0
+yr_rndno_break = 1
 mealcat0-46 = 0
-mealcat47-80 = 0 경우
+mealcat47-80 = 0
-''y hat = 808.013 - 42.960 - 281.683 = 483.37''
+mealcat81-100 = 1 경우
+''**y hat = 808.013 - 42.960 - 281.683 = 483.37**''
 </wrap>  |
 ===== mod4 ← lm(api00 ~ yr_rnd * mealcat, data = datavar) =====
@@ Line 481: / Line 493: @@
 마지막 두 케이스를 보면 no_break학교 중에서 밀카테고리 2와 3에서 떨어지는 정도가 어느 정도 완화되는 경향을 보이지만 통계학적으로 significant하지는 않다.
 [[:r:dummy variables with significant interaction|다른 예]]
+<code>
+> summ(mod4)
+MODEL INFO:
+Observations: 400
+Dependent Variable: api00
+Type: OLS linear regression
+MODEL FIT:
+F(5,394) = 261.61, p = 0.00
+R² = 0.77
+Adj. R² = 0.77
+Standard errors: OLS
+--------------------------------------------------------------------
+                                        Est.    S.E.   t val.      p
+---------------------------------- --------- ------- -------- ------
+(Intercept)                           809.69    6.18   130.91   0.00
+yr_rndno_break                        -74.26   26.76    -2.78   0.01
+mealcat47-80                         -164.41    8.88   -18.52   0.00
+mealcat81-100                        -288.19   10.44   -27.60   0.00
+yr_rndno_break:mealcat47-80            22.52   32.75     0.69   0.49
+yr_rndno_break:mealcat81-100           40.76   29.23     1.39   0.16
+--------------------------------------------------------------------
+>
+</code>
+<code>
+cat_plot(mod4, pred=yr_rnd, modx=mealcat)
+cat_plot(mod4, pred=yr_rnd, modx=mealcat, plot.points = TRUE)
+</code>
+{{:r:pasted:20230607-082841.png}}
+{{:r:pasted:20230607-082903.png}}
+<code>
+cat_plot(mod4, pred=yr_rnd, modx=mealcat, geom = line)
+cat_plot(mod4, pred=yr_rnd, modx=mealcat, geom = "line", point.shape = TRUE)
+cat_plot(mod4, pred=yr_rnd, modx=mealcat, geom = "line", point.shape = TRUE, vary.lty = TRUE)
+</code>
+{{:r:pasted:20230607-082945.png}}
+{{:r:pasted:20230607-083044.png}}
+{{:r:pasted:20230607-083128.png}}
 ====== continus + categorical variables ======
 <code>
@@ Line 697: / Line 751: @@
 </code>
 {{:r:pasted:20230531-085237.png}}
+<code>
+> interact_plot(mod6, pred=some_col, modx=yr_rnd, geom = "line", plot.points = TRUE)
+</code>
+{{:r:pasted:20230607-084836.png}}