Carga de datos

library(readxl)
Ejercicio_regresion <- read_excel("C:/Users/villeda/Desktop/Ejercicio_regresion.xlsx") 
head(Ejercicio_regresion,n=6)
## # A tibble: 6 x 3
##       Y    X1    X2
##   <dbl> <dbl> <dbl>
## 1   320    50   7.4
## 2   450    53   5.1
## 3   370    60   4.2
## 4   470    63   3.9
## 5   420    69   1.4
## 6   500    82   2.2

Correr el modelo

library(stargazer)
Ejercicio<-lm(formula = Y~X1+X2+X1*X2,data = Ejercicio_regresion )

# Usando Stargazer
stargazer(Ejercicio,title = "Ejemplo de Regresion Multiple",type = "text",digits = 8)
## 
## Ejemplo de Regresion Multiple
## ================================================
##                         Dependent variable:     
##                     ----------------------------
##                                  Y              
## ------------------------------------------------
## X1                         2.33911700***        
##                             (0.46612250)        
##                                                 
## X2                         -24.96739000**       
##                            (11.24008000)        
##                                                 
## X1:X2                      0.28435440***        
##                             (0.07506235)        
##                                                 
## Constant                  305.73530000***       
##                            (69.92387000)        
##                                                 
## ------------------------------------------------
## Observations                     20             
## R2                           0.96494280         
## Adjusted R2                  0.95836960         
## Residual Std. Error    66.24833000 (df = 16)    
## F Statistic         146.79910000*** (df = 3; 16)
## ================================================
## Note:                *p<0.1; **p<0.05; ***p<0.01

Matrices A P y M

Mat_x<-model.matrix(Ejercicio)
# Matriz X'X
Mat_xx<-t(Mat_x)%*%Mat_x
print(Mat_xx)
##             (Intercept)        X1        X2      X1:X2
## (Intercept)        20.0    3036.0    118.20    18304.2
## X1               3036.0  574618.0  18304.20  3469532.8
## X2                118.2   18304.2    978.34   149408.7
## X1:X2           18304.2 3469532.8 149408.68 27196881.9
# Matriz A
Mat_a<-solve(Mat_xx)%*%t(Mat_x)
print(Mat_a)
##                         1             2            3             4
## (Intercept) -0.0276842640  2.158537e-01  0.291836335  0.3124221319
## X1           0.0003918313 -1.041498e-03 -0.001463627 -0.0015698882
## X2           0.0390485478 -6.225696e-03 -0.021835104 -0.0263349277
## X1:X2       -0.0002322665  3.172992e-05  0.000119522  0.0001437116
##                         5            6             7             8            9
## (Intercept)  0.5183452229  0.386284989  1.949795e-02  9.135614e-02 -0.261133830
## X1          -0.0026979163 -0.001859120  8.194598e-05 -2.466689e-04  0.001192857
## X2          -0.0654785307 -0.044508158  1.823185e-02  4.094045e-03  0.066500674
## X1:X2        0.0003585806  0.000228333 -9.799670e-05 -3.071165e-05 -0.000287323
##                        10            11            12           13
## (Intercept) -0.2547733810  7.104915e-02 -0.0595114814 -0.076295534
## X1           0.0006282835  4.344447e-04  0.0012530747  0.001118609
## X2           0.0613008667 -3.526758e-03  0.0127819081  0.010778674
## X1:X2       -0.0001670526 -7.228364e-05 -0.0001707218 -0.000117144
##                        14            15            16            17
## (Intercept) -1.640936e-02 -0.2291953094 -0.3326501237 -0.1413146836
## X1           4.092693e-04  0.0024272397  0.0033040996  0.0015130253
## X2          -3.758467e-03  0.0320742161  0.0482576240  0.0126691497
## X1:X2        2.894944e-05 -0.0003046495 -0.0004415541 -0.0001237281
##                        18           19            20
## (Intercept)  0.1854125365  0.303238435  0.0036713425
## X1          -0.0014879184 -0.002553991  0.0001659478
## X2          -0.0478403575 -0.069800891 -0.0164286628
## X1:X2        0.0004077643  0.000597656  0.0001291848
# Matriz P
Matriz_p<-Mat_x%*%Mat_a
print(Matriz_p)
##              1            2             3            4            5
## 1   0.19492794  0.129448747  0.1012983510  0.092222560  0.031583117
## 2   0.12944875  0.137479881  0.1352118632  0.133755179  0.138339500
## 3   0.10129835  0.135211863  0.1424308132  0.143837474  0.171822738
## 4   0.09222256  0.133755179  0.1438374739  0.146122904  0.181113490
## 5   0.03158312  0.138339500  0.1718227379  0.181113490  0.275157947
## 6   0.04845183  0.122478435  0.1453434456  0.151680036  0.217751268
## 7   0.12225213  0.090334996  0.0762932951  0.071686958  0.041210326
## 8   0.09795532  0.090860961  0.0860116614  0.084236925  0.077100906
## 9   0.18430451  0.063577632  0.0173350340  0.002773537 -0.113481154
## 10  0.16845776  0.046005757 -0.0017099765 -0.017162955 -0.141737883
## 11  0.03992843  0.056549983  0.0640879679  0.066904716  0.089105769
## 12  0.03456129  0.025943096  0.0263351113  0.027335311  0.028353615
## 13  0.01605385  0.006297985  0.0065711781  0.007431411  0.004662546
## 14 -0.01304726 -0.006061232 -0.0003435009  0.001829466  0.009364889
## 15  0.01679555 -0.019319870 -0.0256209003 -0.026042154 -0.046241011
## 16  0.02628625 -0.030771044 -0.0429937680 -0.044776966 -0.079760709
## 17 -0.01769112 -0.029955396 -0.0285022289 -0.026984411 -0.031131268
## 18 -0.09212923 -0.027214264 -0.0020354579  0.005283979  0.055159703
## 19 -0.11985502 -0.026561243  0.0074445151  0.016957576  0.087025351
## 20 -0.06180501 -0.036400965 -0.0228176153 -0.018205037  0.004600860
##               6            7             8            9            10
## 1   0.048451827  0.122252134  0.0979553187  0.184304513  0.1684577587
## 2   0.122478435  0.090334996  0.0908609607  0.063577632  0.0460057569
## 3   0.145343446  0.076293295  0.0860116614  0.017335034 -0.0017099765
## 4   0.151680036  0.071686958  0.0842369246  0.002773537 -0.0171629547
## 5   0.217751268  0.041210326  0.0771009064 -0.113481154 -0.1417378825
## 6   0.177110487  0.048648977  0.0745958102 -0.068851138 -0.0985285085
## 7   0.048648977  0.086717782  0.0738494117  0.122530517  0.1202242411
## 8   0.074595810  0.073849412  0.0708327668  0.071652089  0.0609542837
## 9  -0.068851138  0.122530517  0.0716520890  0.319493670  0.3719760955
## 10 -0.098528508  0.120224241  0.0609542837  0.371976096  0.4760816175
## 11  0.085874774  0.039207763  0.0532791324 -0.033060602 -0.0844205911
## 12  0.040562623  0.035764057  0.0424612571 -0.003190585 -0.0509674423
## 13  0.018010743  0.029015344  0.0320353374  0.017899744 -0.0038569927
## 14  0.014104579  0.018472911  0.0218926164  0.023456008  0.0368769932
## 15 -0.014557152  0.024793504  0.0254644114  0.014282309 -0.0371498019
## 16 -0.035203551  0.026475315  0.0242914042  0.019255435 -0.0530855339
## 17 -0.011695038  0.012062196  0.0149080589  0.012468273 -0.0006357297
## 18  0.031715128 -0.012826778 -0.0002983217 -0.005817399  0.0767548162
## 19  0.048066320 -0.022407760 -0.0059512870 -0.015044132  0.1006874688
## 20  0.004440934 -0.004305189  0.0038672579 -0.001559847  0.0312363820
##              11           12           13            14           15
## 1   0.039928428  0.034561293  0.016053855 -0.0130472561  0.016795550
## 2   0.056549983  0.025943096  0.006297985 -0.0060612321 -0.019319870
## 3   0.064087968  0.026335111  0.006571178 -0.0003435009 -0.025620900
## 4   0.066904716  0.027335311  0.007431411  0.0018294658 -0.026042154
## 5   0.089105769  0.028353615  0.004662546  0.0093648889 -0.046241011
## 6   0.085874774  0.040562623  0.018010743  0.0141045790 -0.014557152
## 7   0.039207763  0.035764057  0.029015344  0.0184729113  0.024793504
## 8   0.053279132  0.042461257  0.032035337  0.0218926164  0.025464411
## 9  -0.033060602 -0.003190585  0.017899744  0.0234560082  0.014282309
## 10 -0.084420591 -0.050967442 -0.003856993  0.0368769932 -0.037149802
## 11  0.106040310  0.101514352  0.077230732  0.0462073335  0.106281900
## 12  0.101514352  0.114750680  0.095942043  0.0619643954  0.143239768
## 13  0.077230732  0.095942043  0.091683721  0.0756649826  0.128514663
## 14  0.046207333  0.061964395  0.075664983  0.0880481627  0.086500371
## 15  0.106281900  0.143239768  0.128514663  0.0865003706  0.206032902
## 16  0.125216272  0.173567248  0.150564599  0.0894698349  0.254842212
## 17  0.073269959  0.104338526  0.108858719  0.0990966944  0.155041405
## 18 -0.009794207 -0.008602231  0.040229186  0.1145301521 -0.009600218
## 19 -0.038180509 -0.047746966  0.016497447  0.1203431265 -0.067026142
## 20  0.034756518  0.053873849  0.080692757  0.1116294736  0.083768255
##             16            17            18           19           20
## 1   0.02628625 -0.0176911227 -0.0921292286 -0.119855019 -0.061805013
## 2  -0.03077104 -0.0299553960 -0.0272142641 -0.026561243 -0.036400965
## 3  -0.04299377 -0.0285022289 -0.0020354579  0.007444515 -0.022817615
## 4  -0.04477697 -0.0269844107  0.0052839791  0.016957576 -0.018205037
## 5  -0.07976071 -0.0311312682  0.0551597027  0.087025351  0.004600860
## 6  -0.03520355 -0.0116950377  0.0317151280  0.048066320  0.004440934
## 7   0.02647532  0.0120621962 -0.0128267780 -0.022407760 -0.004305189
## 8   0.02429140  0.0149080589 -0.0002983217 -0.005951287  0.003867258
## 9   0.01925544  0.0124682731 -0.0058173989 -0.015044132 -0.001559847
## 10 -0.05308553 -0.0006357297  0.0767548162  0.100687469  0.031236382
## 11  0.12521627  0.0732699589 -0.0097942070 -0.038180509  0.034756518
## 12  0.17356725  0.1043385263 -0.0086022314 -0.047746966  0.053873849
## 13  0.15056460  0.1088587194  0.0402291862  0.016497447  0.080692757
## 14  0.08946983  0.0990966944  0.1145301521  0.120343127  0.111629474
## 15  0.25484221  0.1550414048 -0.0096002178 -0.067026142  0.083768255
## 16  0.32181689  0.1809499348 -0.0516324790 -0.132991790  0.078480442
## 17  0.18094993  0.1411061996  0.0749555993  0.052223132  0.117316497
## 18 -0.05163248  0.0749555993  0.2832180812  0.357219742  0.180884198
## 19 -0.13299179  0.0522231316  0.3572197419  0.465350583  0.203949588
## 20  0.07848044  0.1173164966  0.1808841976  0.203949588  0.155596657
#Matriz M
Matriz_M<-diag(20)-Matriz_p
print(Matriz_M)
##              1            2             3            4            5
## 1   0.80507206 -0.129448747 -0.1012983510 -0.092222560 -0.031583117
## 2  -0.12944875  0.862520119 -0.1352118632 -0.133755179 -0.138339500
## 3  -0.10129835 -0.135211863  0.8575691868 -0.143837474 -0.171822738
## 4  -0.09222256 -0.133755179 -0.1438374739  0.853877096 -0.181113490
## 5  -0.03158312 -0.138339500 -0.1718227379 -0.181113490  0.724842053
## 6  -0.04845183 -0.122478435 -0.1453434456 -0.151680036 -0.217751268
## 7  -0.12225213 -0.090334996 -0.0762932951 -0.071686958 -0.041210326
## 8  -0.09795532 -0.090860961 -0.0860116614 -0.084236925 -0.077100906
## 9  -0.18430451 -0.063577632 -0.0173350340 -0.002773537  0.113481154
## 10 -0.16845776 -0.046005757  0.0017099765  0.017162955  0.141737883
## 11 -0.03992843 -0.056549983 -0.0640879679 -0.066904716 -0.089105769
## 12 -0.03456129 -0.025943096 -0.0263351113 -0.027335311 -0.028353615
## 13 -0.01605385 -0.006297985 -0.0065711781 -0.007431411 -0.004662546
## 14  0.01304726  0.006061232  0.0003435009 -0.001829466 -0.009364889
## 15 -0.01679555  0.019319870  0.0256209003  0.026042154  0.046241011
## 16 -0.02628625  0.030771044  0.0429937680  0.044776966  0.079760709
## 17  0.01769112  0.029955396  0.0285022289  0.026984411  0.031131268
## 18  0.09212923  0.027214264  0.0020354579 -0.005283979 -0.055159703
## 19  0.11985502  0.026561243 -0.0074445151 -0.016957576 -0.087025351
## 20  0.06180501  0.036400965  0.0228176153  0.018205037 -0.004600860
##               6            7             8            9            10
## 1  -0.048451827 -0.122252134 -0.0979553187 -0.184304513 -0.1684577587
## 2  -0.122478435 -0.090334996 -0.0908609607 -0.063577632 -0.0460057569
## 3  -0.145343446 -0.076293295 -0.0860116614 -0.017335034  0.0017099765
## 4  -0.151680036 -0.071686958 -0.0842369246 -0.002773537  0.0171629547
## 5  -0.217751268 -0.041210326 -0.0771009064  0.113481154  0.1417378825
## 6   0.822889513 -0.048648977 -0.0745958102  0.068851138  0.0985285085
## 7  -0.048648977  0.913282218 -0.0738494117 -0.122530517 -0.1202242411
## 8  -0.074595810 -0.073849412  0.9291672332 -0.071652089 -0.0609542837
## 9   0.068851138 -0.122530517 -0.0716520890  0.680506330 -0.3719760955
## 10  0.098528508 -0.120224241 -0.0609542837 -0.371976096  0.5239183825
## 11 -0.085874774 -0.039207763 -0.0532791324  0.033060602  0.0844205911
## 12 -0.040562623 -0.035764057 -0.0424612571  0.003190585  0.0509674423
## 13 -0.018010743 -0.029015344 -0.0320353374 -0.017899744  0.0038569927
## 14 -0.014104579 -0.018472911 -0.0218926164 -0.023456008 -0.0368769932
## 15  0.014557152 -0.024793504 -0.0254644114 -0.014282309  0.0371498019
## 16  0.035203551 -0.026475315 -0.0242914042 -0.019255435  0.0530855339
## 17  0.011695038 -0.012062196 -0.0149080589 -0.012468273  0.0006357297
## 18 -0.031715128  0.012826778  0.0002983217  0.005817399 -0.0767548162
## 19 -0.048066320  0.022407760  0.0059512870  0.015044132 -0.1006874688
## 20 -0.004440934  0.004305189 -0.0038672579  0.001559847 -0.0312363820
##              11           12           13            14           15
## 1  -0.039928428 -0.034561293 -0.016053855  0.0130472561 -0.016795550
## 2  -0.056549983 -0.025943096 -0.006297985  0.0060612321  0.019319870
## 3  -0.064087968 -0.026335111 -0.006571178  0.0003435009  0.025620900
## 4  -0.066904716 -0.027335311 -0.007431411 -0.0018294658  0.026042154
## 5  -0.089105769 -0.028353615 -0.004662546 -0.0093648889  0.046241011
## 6  -0.085874774 -0.040562623 -0.018010743 -0.0141045790  0.014557152
## 7  -0.039207763 -0.035764057 -0.029015344 -0.0184729113 -0.024793504
## 8  -0.053279132 -0.042461257 -0.032035337 -0.0218926164 -0.025464411
## 9   0.033060602  0.003190585 -0.017899744 -0.0234560082 -0.014282309
## 10  0.084420591  0.050967442  0.003856993 -0.0368769932  0.037149802
## 11  0.893959690 -0.101514352 -0.077230732 -0.0462073335 -0.106281900
## 12 -0.101514352  0.885249320 -0.095942043 -0.0619643954 -0.143239768
## 13 -0.077230732 -0.095942043  0.908316279 -0.0756649826 -0.128514663
## 14 -0.046207333 -0.061964395 -0.075664983  0.9119518373 -0.086500371
## 15 -0.106281900 -0.143239768 -0.128514663 -0.0865003706  0.793967098
## 16 -0.125216272 -0.173567248 -0.150564599 -0.0894698349 -0.254842212
## 17 -0.073269959 -0.104338526 -0.108858719 -0.0990966944 -0.155041405
## 18  0.009794207  0.008602231 -0.040229186 -0.1145301521  0.009600218
## 19  0.038180509  0.047746966 -0.016497447 -0.1203431265  0.067026142
## 20 -0.034756518 -0.053873849 -0.080692757 -0.1116294736 -0.083768255
##             16            17            18           19           20
## 1  -0.02628625  0.0176911227  0.0921292286  0.119855019  0.061805013
## 2   0.03077104  0.0299553960  0.0272142641  0.026561243  0.036400965
## 3   0.04299377  0.0285022289  0.0020354579 -0.007444515  0.022817615
## 4   0.04477697  0.0269844107 -0.0052839791 -0.016957576  0.018205037
## 5   0.07976071  0.0311312682 -0.0551597027 -0.087025351 -0.004600860
## 6   0.03520355  0.0116950377 -0.0317151280 -0.048066320 -0.004440934
## 7  -0.02647532 -0.0120621962  0.0128267780  0.022407760  0.004305189
## 8  -0.02429140 -0.0149080589  0.0002983217  0.005951287 -0.003867258
## 9  -0.01925544 -0.0124682731  0.0058173989  0.015044132  0.001559847
## 10  0.05308553  0.0006357297 -0.0767548162 -0.100687469 -0.031236382
## 11 -0.12521627 -0.0732699589  0.0097942070  0.038180509 -0.034756518
## 12 -0.17356725 -0.1043385263  0.0086022314  0.047746966 -0.053873849
## 13 -0.15056460 -0.1088587194 -0.0402291862 -0.016497447 -0.080692757
## 14 -0.08946983 -0.0990966944 -0.1145301521 -0.120343127 -0.111629474
## 15 -0.25484221 -0.1550414048  0.0096002178  0.067026142 -0.083768255
## 16  0.67818311 -0.1809499348  0.0516324790  0.132991790 -0.078480442
## 17 -0.18094993  0.8588938004 -0.0749555993 -0.052223132 -0.117316497
## 18  0.05163248 -0.0749555993  0.7167819188 -0.357219742 -0.180884198
## 19  0.13299179 -0.0522231316 -0.3572197419  0.534649417 -0.203949588
## 20 -0.07848044 -0.1173164966 -0.1808841976 -0.203949588  0.844403343

Vector de coeficientes estimados

options(scipen = 999)
Ejercicio$coefficients
## (Intercept)          X1          X2       X1:X2 
## 305.7353274   2.3391170 -24.9673923   0.2843544

Matriz de varianza-covarianza

var_covar<-vcov(Ejercicio)
print(var_covar)
##             (Intercept)           X1           X2        X1:X2
## (Intercept) 4889.347295 -29.91920102 -691.1337600  4.322975022
## X1           -29.919201   0.21727017    4.3932767 -0.031715864
## X2          -691.133760   4.39327667  126.3393908 -0.789361391
## X1:X2          4.322975  -0.03171586   -0.7893614  0.005634356

Intervalo de confianza

confint(object = Ejercicio,level = .95)
##                   2.5 %      97.5 %
## (Intercept) 157.5033494 453.9673054
## X1            1.3509814   3.3272525
## X2          -48.7952967  -1.1394879
## X1:X2         0.1252294   0.4434795

Valores ajustados

plot(Ejercicio$fitted.values,main = "Valores Ajustados",ylab = "Y",xlab = "casos")

# Residuos del modelo

plot(Ejercicio$residuals,main = "Residuos",ylab = "Residuos",xlab = "casos")

library(dplyr)
Ejercicio$residuals %>% matrix()
##              [,1]
##  [1,]  -23.143607
##  [2,]   70.764175
##  [3,]  -42.876610
##  [4,]   44.407254
##  [5,]  -39.648685
##  [6,]    6.087808
##  [7,]    6.076630
##  [8,]   64.745346
##  [9,]    6.087450
## [10,]  -26.598918
## [11,]   -3.742989
## [12,] -105.967693
## [13,]  -14.361853
## [14,] -111.096309
## [15,]  -29.872373
## [16,]   99.010200
## [17,]   69.618669
## [18,]  -71.856927
## [19,]   98.872286
## [20,]    3.496145