Tablas de Frecuencia

library(foreign)

auto<-read.dta("auto.dta")
head(auto)

##            make price mpg rep78 headroom trunk weight length turn
## 1   AMC Concord  4099  22     3      2.5    11   2930    186   40
## 2     AMC Pacer  4749  17     3      3.0    11   3350    173   40
## 3    AMC Spirit  3799  22    NA      3.0    12   2640    168   35
## 4 Buick Century  4816  20     3      4.5    16   3250    196   40
## 5 Buick Electra  7827  15     4      4.0    20   4080    222   43
## 6 Buick LeSabre  5788  18     3      4.0    21   3670    218   43
##   displacement gear_ratio  foreign
## 1          121       3.58 Domestic
## 2          258       2.53 Domestic
## 3          121       3.08 Domestic
## 4          196       2.93 Domestic
## 5          350       2.41 Domestic
## 6          231       2.73 Domestic

library(vcd)

## Loading required package: grid

BASE DE DATOS “ARTHRITIS”

head(Arthritis)

##   ID Treatment  Sex Age Improved
## 1 57   Treated Male  27     Some
## 2 46   Treated Male  29     None
## 3 77   Treated Male  30     None
## 4 17   Treated Male  32   Marked
## 5 36   Treated Male  46   Marked
## 6 23   Treated Male  58   Marked

Tablas de Frecuencias Univariadas

Tablas Cruzadas

Paquete a usar

library("gmodels")   # Tablas Cruzadas
library("AMR")       # Tablas Univariadas

Tablas Cruzadas con la Base Arthritis

CrossTable(Arthritis$Treatment,Arthritis$Improved)

## 
##  
##    Cell Contents
## |-------------------------|
## |                       N |
## | Chi-square contribution |
## |           N / Row Total |
## |           N / Col Total |
## |         N / Table Total |
## |-------------------------|
## 
##  
## Total Observations in Table:  84 
## 
##  
##                     | Arthritis$Improved 
## Arthritis$Treatment |      None |      Some |    Marked | Row Total | 
## --------------------|-----------|-----------|-----------|-----------|
##             Placebo |        29 |         7 |         7 |        43 | 
##                     |     2.616 |     0.004 |     3.752 |           | 
##                     |     0.674 |     0.163 |     0.163 |     0.512 | 
##                     |     0.690 |     0.500 |     0.250 |           | 
##                     |     0.345 |     0.083 |     0.083 |           | 
## --------------------|-----------|-----------|-----------|-----------|
##             Treated |        13 |         7 |        21 |        41 | 
##                     |     2.744 |     0.004 |     3.935 |           | 
##                     |     0.317 |     0.171 |     0.512 |     0.488 | 
##                     |     0.310 |     0.500 |     0.750 |           | 
##                     |     0.155 |     0.083 |     0.250 |           | 
## --------------------|-----------|-----------|-----------|-----------|
##        Column Total |        42 |        14 |        28 |        84 | 
##                     |     0.500 |     0.167 |     0.333 |           | 
## --------------------|-----------|-----------|-----------|-----------|
## 
## 

CrossTable(Arthritis$Treatment,Arthritis$Improved,format = "SPSS", chisq = TRUE)

## 
##    Cell Contents
## |-------------------------|
## |                   Count |
## | Chi-square contribution |
## |             Row Percent |
## |          Column Percent |
## |           Total Percent |
## |-------------------------|
## 
## Total Observations in Table:  84 
## 
##                     | Arthritis$Improved 
## Arthritis$Treatment |     None  |     Some  |   Marked  | Row Total | 
## --------------------|-----------|-----------|-----------|-----------|
##             Placebo |       29  |        7  |        7  |       43  | 
##                     |    2.616  |    0.004  |    3.752  |           | 
##                     |   67.442% |   16.279% |   16.279% |   51.190% | 
##                     |   69.048% |   50.000% |   25.000% |           | 
##                     |   34.524% |    8.333% |    8.333% |           | 
## --------------------|-----------|-----------|-----------|-----------|
##             Treated |       13  |        7  |       21  |       41  | 
##                     |    2.744  |    0.004  |    3.935  |           | 
##                     |   31.707% |   17.073% |   51.220% |   48.810% | 
##                     |   30.952% |   50.000% |   75.000% |           | 
##                     |   15.476% |    8.333% |   25.000% |           | 
## --------------------|-----------|-----------|-----------|-----------|
##        Column Total |       42  |       14  |       28  |       84  | 
##                     |   50.000% |   16.667% |   33.333% |           | 
## --------------------|-----------|-----------|-----------|-----------|
## 
##  
## Statistics for All Table Factors
## 
## 
## Pearson's Chi-squared test 
## ------------------------------------------------------------
## Chi^2 =  13.05502     d.f. =  2     p =  0.001462643 
## 
## 
##  
##        Minimum expected frequency: 6.833333

CrossTable(Arthritis$Treatment,Arthritis$Improved,format = "SPSS", 
           prop.chisq = FALSE, prop.r = FALSE,prop.t = FALSE)

## 
##    Cell Contents
## |-------------------------|
## |                   Count |
## |          Column Percent |
## |-------------------------|
## 
## Total Observations in Table:  84 
## 
##                     | Arthritis$Improved 
## Arthritis$Treatment |     None  |     Some  |   Marked  | Row Total | 
## --------------------|-----------|-----------|-----------|-----------|
##             Placebo |       29  |        7  |        7  |       43  | 
##                     |   69.048% |   50.000% |   25.000% |           | 
## --------------------|-----------|-----------|-----------|-----------|
##             Treated |       13  |        7  |       21  |       41  | 
##                     |   30.952% |   50.000% |   75.000% |           | 
## --------------------|-----------|-----------|-----------|-----------|
##        Column Total |       42  |       14  |       28  |       84  | 
##                     |   50.000% |   16.667% |   33.333% |           | 
## --------------------|-----------|-----------|-----------|-----------|
## 
## 

CrossTable(Arthritis$Improved,Arthritis$Treatment,format = "SPSS", 
           prop.chisq = FALSE, prop.r = FALSE,prop.t = FALSE,chisq=TRUE)

## 
##    Cell Contents
## |-------------------------|
## |                   Count |
## |          Column Percent |
## |-------------------------|
## 
## Total Observations in Table:  84 
## 
##                    | Arthritis$Treatment 
## Arthritis$Improved |  Placebo  |  Treated  | Row Total | 
## -------------------|-----------|-----------|-----------|
##               None |       29  |       13  |       42  | 
##                    |   67.442% |   31.707% |           | 
## -------------------|-----------|-----------|-----------|
##               Some |        7  |        7  |       14  | 
##                    |   16.279% |   17.073% |           | 
## -------------------|-----------|-----------|-----------|
##             Marked |        7  |       21  |       28  | 
##                    |   16.279% |   51.220% |           | 
## -------------------|-----------|-----------|-----------|
##       Column Total |       43  |       41  |       84  | 
##                    |   51.190% |   48.810% |           | 
## -------------------|-----------|-----------|-----------|
## 
##  
## Statistics for All Table Factors
## 
## 
## Pearson's Chi-squared test 
## ------------------------------------------------------------
## Chi^2 =  13.05502     d.f. =  2     p =  0.001462643 
## 
## 
##  
##        Minimum expected frequency: 6.833333

Tabla cruzada de la base auto entre las variables mpg y foreign

1. Obtenemos el rango de la variable

range(auto$mpg)

## [1] 12 41

2. Determinamos los limites de lo intervalos

breaks2 = seq(10, 45, by=5)
breaks2

## [1] 10 15 20 25 30 35 40 45

3. Establecemos los intervalos

mpg.corte = cut(auto$mpg, breaks2, right=TRUE)

table(mpg.corte)

## mpg.corte
## (10,15] (15,20] (20,25] (25,30] (30,35] (35,40] (40,45] 
##      10      28      22       9       4       0       1

4. Tabla de Frecuencia univariada de mpg

transform(table(mpg.corte))

##   mpg.corte Freq
## 1   (10,15]   10
## 2   (15,20]   28
## 3   (20,25]   22
## 4   (25,30]    9
## 5   (30,35]    4
## 6   (35,40]    0
## 7   (40,45]    1

cbind(Freq=table(mpg.corte), Cumul=cumsum(table(mpg.corte)), relative=prop.table(table(mpg.corte)))

##         Freq Cumul   relative
## (10,15]   10    10 0.13513514
## (15,20]   28    38 0.37837838
## (20,25]   22    60 0.29729730
## (25,30]    9    69 0.12162162
## (30,35]    4    73 0.05405405
## (35,40]    0    73 0.00000000
## (40,45]    1    74 0.01351351

5. Tabla cruzada

CrossTable(cut(auto$mpg, breaks2, right=TRUE),auto$foreign,format = "SPSS",
           prop.chisq = FALSE, prop.r = FALSE,prop.t = FALSE)

## 
##    Cell Contents
## |-------------------------|
## |                   Count |
## |          Column Percent |
## |-------------------------|
## 
## Total Observations in Table:  74 
## 
##                                      | auto$foreign 
## cut(auto$mpg, breaks2, right = TRUE) | Domestic  |  Foreign  | Row Total | 
## -------------------------------------|-----------|-----------|-----------|
##                              (10,15] |        9  |        1  |       10  | 
##                                      |   17.308% |    4.545% |           | 
## -------------------------------------|-----------|-----------|-----------|
##                              (15,20] |       24  |        4  |       28  | 
##                                      |   46.154% |   18.182% |           | 
## -------------------------------------|-----------|-----------|-----------|
##                              (20,25] |       12  |       10  |       22  | 
##                                      |   23.077% |   45.455% |           | 
## -------------------------------------|-----------|-----------|-----------|
##                              (25,30] |        6  |        3  |        9  | 
##                                      |   11.538% |   13.636% |           | 
## -------------------------------------|-----------|-----------|-----------|
##                              (30,35] |        1  |        3  |        4  | 
##                                      |    1.923% |   13.636% |           | 
## -------------------------------------|-----------|-----------|-----------|
##                              (40,45] |        0  |        1  |        1  | 
##                                      |    0.000% |    4.545% |           | 
## -------------------------------------|-----------|-----------|-----------|
##                         Column Total |       52  |       22  |       74  | 
##                                      |   70.270% |   29.730% |           | 
## -------------------------------------|-----------|-----------|-----------|
## 
##