# Cargando base
data("USArrests")
?USArrests
## starting httpd help server ... done
josep <-USArrests  # nombre de base de datos
View(josep)        # ver mi base de datos

# Exploración de datos

class(josep)
## [1] "data.frame"
nrow(josep) # numero de filas
## [1] 50
ncol(josep) # nuemro de columnas
## [1] 4
names(josep) # nombres de variables
## [1] "Murder"   "Assault"  "UrbanPop" "Rape"
colnames(josep) # nombre de columnas
## [1] "Murder"   "Assault"  "UrbanPop" "Rape"
head(josep) # 6 primeros casos
##            Murder Assault UrbanPop Rape
## Alabama      13.2     236       58 21.2
## Alaska       10.0     263       48 44.5
## Arizona       8.1     294       80 31.0
## Arkansas      8.8     190       50 19.5
## California    9.0     276       91 40.6
## Colorado      7.9     204       78 38.7
tail(josep) # 6 ultimos casos
##               Murder Assault UrbanPop Rape
## Vermont          2.2      48       32 11.2
## Virginia         8.5     156       63 20.7
## Washington       4.0     145       73 26.2
## West Virginia    5.7      81       39  9.3
## Wisconsin        2.6      53       66 10.8
## Wyoming          6.8     161       60 15.6
attributes(josep) # resumen general
## $names
## [1] "Murder"   "Assault"  "UrbanPop" "Rape"    
## 
## $class
## [1] "data.frame"
## 
## $row.names
##  [1] "Alabama"        "Alaska"         "Arizona"        "Arkansas"      
##  [5] "California"     "Colorado"       "Connecticut"    "Delaware"      
##  [9] "Florida"        "Georgia"        "Hawaii"         "Idaho"         
## [13] "Illinois"       "Indiana"        "Iowa"           "Kansas"        
## [17] "Kentucky"       "Louisiana"      "Maine"          "Maryland"      
## [21] "Massachusetts"  "Michigan"       "Minnesota"      "Mississippi"   
## [25] "Missouri"       "Montana"        "Nebraska"       "Nevada"        
## [29] "New Hampshire"  "New Jersey"     "New Mexico"     "New York"      
## [33] "North Carolina" "North Dakota"   "Ohio"           "Oklahoma"      
## [37] "Oregon"         "Pennsylvania"   "Rhode Island"   "South Carolina"
## [41] "South Dakota"   "Tennessee"      "Texas"          "Utah"          
## [45] "Vermont"        "Virginia"       "Washington"     "West Virginia" 
## [49] "Wisconsin"      "Wyoming"

# Exploración y observación de datos

josep[15,]  # numero d caso
##      Murder Assault UrbanPop Rape
## Iowa    2.2      56       57 11.3
josep[23,] # numero de caso
##           Murder Assault UrbanPop Rape
## Minnesota    2.7      72       66 14.9
josep[c(26:30),]
##               Murder Assault UrbanPop Rape
## Montana          6.0     109       53 16.4
## Nebraska         4.3     102       62 16.5
## Nevada          12.2     252       81 46.0
## New Hampshire    2.1      57       56  9.5
## New Jersey       7.4     159       89 18.8

# Asignando a mi base de datos

joseplastra <- josep[26,]
josepvasquez <- josep[c(26:30),]
josepabel <- josep[ "Missouri",] 
joseplas <- josep[-5,] # eliminar 1 caso
josepvas <- josep[c(-26:-30),] # eliminar varios casos

# Columnas

josep[,4] # varaible 4
##  [1] 21.2 44.5 31.0 19.5 40.6 38.7 11.1 15.8 31.9 25.8 20.2 14.2 24.0 21.0 11.3
## [16] 18.0 16.3 22.2  7.8 27.8 16.3 35.1 14.9 17.1 28.2 16.4 16.5 46.0  9.5 18.8
## [31] 32.1 26.1 16.1  7.3 21.4 20.0 29.3 14.9  8.3 22.5 12.8 26.9 25.5 22.9 11.2
## [46] 20.7 26.2  9.3 10.8 15.6
josep[,c(2:4)] # varias variables
##                Assault UrbanPop Rape
## Alabama            236       58 21.2
## Alaska             263       48 44.5
## Arizona            294       80 31.0
## Arkansas           190       50 19.5
## California         276       91 40.6
## Colorado           204       78 38.7
## Connecticut        110       77 11.1
## Delaware           238       72 15.8
## Florida            335       80 31.9
## Georgia            211       60 25.8
## Hawaii              46       83 20.2
## Idaho              120       54 14.2
## Illinois           249       83 24.0
## Indiana            113       65 21.0
## Iowa                56       57 11.3
## Kansas             115       66 18.0
## Kentucky           109       52 16.3
## Louisiana          249       66 22.2
## Maine               83       51  7.8
## Maryland           300       67 27.8
## Massachusetts      149       85 16.3
## Michigan           255       74 35.1
## Minnesota           72       66 14.9
## Mississippi        259       44 17.1
## Missouri           178       70 28.2
## Montana            109       53 16.4
## Nebraska           102       62 16.5
## Nevada             252       81 46.0
## New Hampshire       57       56  9.5
## New Jersey         159       89 18.8
## New Mexico         285       70 32.1
## New York           254       86 26.1
## North Carolina     337       45 16.1
## North Dakota        45       44  7.3
## Ohio               120       75 21.4
## Oklahoma           151       68 20.0
## Oregon             159       67 29.3
## Pennsylvania       106       72 14.9
## Rhode Island       174       87  8.3
## South Carolina     279       48 22.5
## South Dakota        86       45 12.8
## Tennessee          188       59 26.9
## Texas              201       80 25.5
## Utah               120       80 22.9
## Vermont             48       32 11.2
## Virginia           156       63 20.7
## Washington         145       73 26.2
## West Virginia       81       39  9.3
## Wisconsin           53       66 10.8
## Wyoming            161       60 15.6
josep1 <-josep[,c(2:4)]
josep$Assault
##  [1] 236 263 294 190 276 204 110 238 335 211  46 120 249 113  56 115 109 249  83
## [20] 300 149 255  72 259 178 109 102 252  57 159 285 254 337  45 120 151 159 106
## [39] 174 279  86 188 201 120  48 156 145  81  53 161
josep2 <- josep$Assault
josep2 <- data.frame(josep[,2]) # un base de datos con una sola variable
josep[26,]
##         Murder Assault UrbanPop Rape
## Montana      6     109       53 16.4
josep[26,4] # indice de violación de Montana
## [1] 16.4