Curso: S3-P2 Asignatura: Programación
John Escorza
Erika Ortiz
Lesly Proaño
Josheline Quilumbaquin
Docente: Francisco Valverde (PhD en Informática)
-Utilizando la base de datos interna mtcars, resolver los siguientes enunciados:
#install.packages("dplyr")
library(dplyr)
## Warning: package 'dplyr' was built under R version 4.3.2
##
## Attaching package: 'dplyr'
## The following objects are masked from 'package:stats':
##
## filter, lag
## The following objects are masked from 'package:base':
##
## intersect, setdiff, setequal, union
#install.packages("tidyverse")
library(tidyverse)
## Warning: package 'tidyverse' was built under R version 4.3.2
## Warning: package 'ggplot2' was built under R version 4.3.2
## Warning: package 'tibble' was built under R version 4.3.2
## Warning: package 'tidyr' was built under R version 4.3.2
## Warning: package 'readr' was built under R version 4.3.2
## Warning: package 'purrr' was built under R version 4.3.2
## Warning: package 'stringr' was built under R version 4.3.2
## Warning: package 'forcats' was built under R version 4.3.2
## Warning: package 'lubridate' was built under R version 4.3.2
## ── Attaching core tidyverse packages ──────────────────────── tidyverse 2.0.0 ──
## ✔ forcats 1.0.0 ✔ readr 2.1.4
## ✔ ggplot2 3.4.4 ✔ stringr 1.5.1
## ✔ lubridate 1.9.3 ✔ tibble 3.2.1
## ✔ purrr 1.0.2 ✔ tidyr 1.3.0
## ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ──
## ✖ dplyr::filter() masks stats::filter()
## ✖ dplyr::lag() masks stats::lag()
## ℹ Use the conflicted package (<http://conflicted.r-lib.org/>) to force all conflicts to become errors
View(mtcars)
head(mtcars)
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1
## Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
## Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2
## Valiant 18.1 6 225 105 2.76 3.460 20.22 1 0 3 1
Existen dos formas de seleccionar las columnas
FORMA 1:
head(select(mtcars,1,2,3))
## mpg cyl disp
## Mazda RX4 21.0 6 160
## Mazda RX4 Wag 21.0 6 160
## Datsun 710 22.8 4 108
## Hornet 4 Drive 21.4 6 258
## Hornet Sportabout 18.7 8 360
## Valiant 18.1 6 225
head(select(mtcars,1:3))
## mpg cyl disp
## Mazda RX4 21.0 6 160
## Mazda RX4 Wag 21.0 6 160
## Datsun 710 22.8 4 108
## Hornet 4 Drive 21.4 6 258
## Hornet Sportabout 18.7 8 360
## Valiant 18.1 6 225
?select_helpers
## starting httpd help server ... done
#Help on topic 'select_helpers' was found in the following packages:
#Objects exported from other packages
#(in package dplyr in library C:/Users/qnoem/AppData/Local/R/win-library/4.3)
#Selection language
#(in package tidyselect in library C:/Users/qnoem/AppData/Local/R/win-library/4.3)
#Objects exported from other packages
#(in package tidyr in library C:/Users/qnoem/AppData/Local/R/win-library/4.3)
head(select(mtcars,starts_with("d")))
## disp drat
## Mazda RX4 160 3.90
## Mazda RX4 Wag 160 3.90
## Datsun 710 108 3.85
## Hornet 4 Drive 258 3.08
## Hornet Sportabout 360 3.15
## Valiant 225 2.76
head(select(mtcars,starts_with("p")))
## data frame with 0 columns and 6 rows
head(select( mtcars, -drat, -am ))
## mpg cyl disp hp wt qsec vs gear carb
## Mazda RX4 21.0 6 160 110 2.620 16.46 0 4 4
## Mazda RX4 Wag 21.0 6 160 110 2.875 17.02 0 4 4
## Datsun 710 22.8 4 108 93 2.320 18.61 1 4 1
## Hornet 4 Drive 21.4 6 258 110 3.215 19.44 1 3 1
## Hornet Sportabout 18.7 8 360 175 3.440 17.02 0 3 2
## Valiant 18.1 6 225 105 3.460 20.22 1 3 1
EXPLICACIÓN: Muestra todas las columnas de mtcars excepto las columnas drat y am se descartan por el (-).
head(select( mtcars, contains( "a" ) ))
## drat am gear carb
## Mazda RX4 3.90 1 4 4
## Mazda RX4 Wag 3.90 1 4 4
## Datsun 710 3.85 1 4 1
## Hornet 4 Drive 3.08 0 3 1
## Hornet Sportabout 3.15 0 3 2
## Valiant 2.76 0 3 1
EXPLICAIÓN: Selecciona las columnas que contengan la letra “a” en el nombre de la variable.
head(filter( mtcars, mpg > 20, gear == 4))
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
## Merc 240D 24.4 4 146.7 62 3.69 3.190 20.00 1 0 4 2
## Merc 230 22.8 4 140.8 95 3.92 3.150 22.90 1 0 4 2
## Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1
EXPLICACIÓN: Selecciona los datos de las columnas mpg mayores a 20 y datos de la columna gear igual a 4 mientras las otras columnas siguen igual.
#Seleccionar los sujetos con tipo de transmisión (am) 1 que, además, tienen 6 cilindros o menos
head(filter(mtcars, am == 1, cyl <= 6))
## mpg cyl disp hp drat wt qsec vs am gear carb
## Mazda RX4 21.0 6 160.0 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 21.0 6 160.0 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 22.8 4 108.0 93 3.85 2.320 18.61 1 1 4 1
## Fiat 128 32.4 4 78.7 66 4.08 2.200 19.47 1 1 4 1
## Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2
## Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.90 1 1 4 1
#Seleccionar los sujetos que bien consumen menos de 21 mpg o bien tienen menos de 3 carburantes (carb) y menos de 4 engranajes (gear)
head(filter(mtcars, (mpg < 21 | carb < 3) & gear < 4))
## mpg cyl disp hp drat wt qsec vs am gear carb
## Hornet 4 Drive 21.4 6 258.0 110 3.08 3.215 19.44 1 0 3 1
## Hornet Sportabout 18.7 8 360.0 175 3.15 3.440 17.02 0 0 3 2
## Valiant 18.1 6 225.0 105 2.76 3.460 20.22 1 0 3 1
## Duster 360 14.3 8 360.0 245 3.21 3.570 15.84 0 0 3 4
## Merc 450SE 16.4 8 275.8 180 3.07 4.070 17.40 0 0 3 3
## Merc 450SL 17.3 8 275.8 180 3.07 3.730 17.60 0 0 3 3
#Ordena por cilindrada (cyl) y por desplazamiento (disp)
head(select(mtcars, cyl, disp, everything()))
## cyl disp mpg hp drat wt qsec vs am gear carb
## Mazda RX4 6 160 21.0 110 3.90 2.620 16.46 0 1 4 4
## Mazda RX4 Wag 6 160 21.0 110 3.90 2.875 17.02 0 1 4 4
## Datsun 710 4 108 22.8 93 3.85 2.320 18.61 1 1 4 1
## Hornet 4 Drive 6 258 21.4 110 3.08 3.215 19.44 1 0 3 1
## Hornet Sportabout 8 360 18.7 175 3.15 3.440 17.02 0 0 3 2
## Valiant 6 225 18.1 105 2.76 3.460 20.22 1 0 3 1
#Crea una nueva columna que indique los kilogramos que pesa el coche, sabiendo que 1 libra = 0.45 kg. La variable wt indica el peso en libras.
mtcars$kg <- (mtcars$wt*0.45)
head(mtcars)
## mpg cyl disp hp drat wt qsec vs am gear carb kg
## Mazda RX4 21.0 6 160 110 3.90 2.620 16.46 0 1 4 4 1.17900
## Mazda RX4 Wag 21.0 6 160 110 3.90 2.875 17.02 0 1 4 4 1.29375
## Datsun 710 22.8 4 108 93 3.85 2.320 18.61 1 1 4 1 1.04400
## Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1 1.44675
## Hornet Sportabout 18.7 8 360 175 3.15 3.440 17.02 0 0 3 2 1.54800
## Valiant 18.1 6 225 105 2.76 3.460 20.22 1 0 3 1 1.55700
#La función summarise() agrupa los valores en una tabla de acuerdo a la función que indiquemos. Calcula la media de disp usando la función summarise:
grupo_calc <- group_by(mtcars, disp)
grupo_calc
## # A tibble: 32 × 12
## # Groups: disp [27]
## mpg cyl disp hp drat wt qsec vs am gear carb kg
## <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl> <dbl>
## 1 21 6 160 110 3.9 2.62 16.5 0 1 4 4 1.18
## 2 21 6 160 110 3.9 2.88 17.0 0 1 4 4 1.29
## 3 22.8 4 108 93 3.85 2.32 18.6 1 1 4 1 1.04
## 4 21.4 6 258 110 3.08 3.22 19.4 1 0 3 1 1.45
## 5 18.7 8 360 175 3.15 3.44 17.0 0 0 3 2 1.55
## 6 18.1 6 225 105 2.76 3.46 20.2 1 0 3 1 1.56
## 7 14.3 8 360 245 3.21 3.57 15.8 0 0 3 4 1.61
## 8 24.4 4 147. 62 3.69 3.19 20 1 0 4 2 1.44
## 9 22.8 4 141. 95 3.92 3.15 22.9 1 0 4 2 1.42
## 10 19.2 6 168. 123 3.92 3.44 18.3 1 0 4 4 1.55
## # ℹ 22 more rows
summarise(grupo_calc, mean(disp))
## # A tibble: 27 × 2
## disp `mean(disp)`
## <dbl> <dbl>
## 1 71.1 71.1
## 2 75.7 75.7
## 3 78.7 78.7
## 4 79 79
## 5 95.1 95.1
## 6 108 108
## 7 120. 120.
## 8 120. 120.
## 9 121 121
## 10 141. 141.
## # ℹ 17 more rows
#summarise(group_by(mtcars, cyl), max = max(disp)) (Explica que resultado obtienes ?)
summarise(group_by(mtcars, cyl), max = max(disp))
## # A tibble: 3 × 2
## cyl max
## <dbl> <dbl>
## 1 4 147.
## 2 6 258
## 3 8 472
Explicación: Este codigo lo que hizo fue Agrupa los datos del cilindraje por su valor y finalmente obtiene el máximo de ese conjunto de datos.
#mtcars %>% select( mpg:disp )%>% head (Explica que resultado obtienes ?)
mtcars %>% select(mpg:disp)%>% head
## mpg cyl disp
## Mazda RX4 21.0 6 160
## Mazda RX4 Wag 21.0 6 160
## Datsun 710 22.8 4 108
## Hornet 4 Drive 21.4 6 258
## Hornet Sportabout 18.7 8 360
## Valiant 18.1 6 225
Explicación: Lo que hace este código es seleccionar las columnas desde mpg hasta disp y nos muestra los 6 primeros valores de esta.
##head(select(select(mtcars, contains(“a”)), -drat, -am)) (Explica que resultado obtienes ?) #### PROCEDIMIENTO
head(select(select(mtcars, contains("a")), -drat, -am))
## gear carb
## Mazda RX4 4 4
## Mazda RX4 Wag 4 4
## Datsun 710 4 1
## Hornet 4 Drive 3 1
## Hornet Sportabout 3 2
## Valiant 3 1
Explicación: Obtengo las columnas de la data mtcars que contengan la letra “a”en su nombre, menos la columna drat y am.
##Utilizando pipes ejecuta el ejercicio 15 #### PROCEDIMIENTO
mtcars %>%
select((contains("a")), -drat, -am)
## gear carb
## Mazda RX4 4 4
## Mazda RX4 Wag 4 4
## Datsun 710 4 1
## Hornet 4 Drive 3 1
## Hornet Sportabout 3 2
## Valiant 3 1
## Duster 360 3 4
## Merc 240D 4 2
## Merc 230 4 2
## Merc 280 4 4
## Merc 280C 4 4
## Merc 450SE 3 3
## Merc 450SL 3 3
## Merc 450SLC 3 3
## Cadillac Fleetwood 3 4
## Lincoln Continental 3 4
## Chrysler Imperial 3 4
## Fiat 128 4 1
## Honda Civic 4 2
## Toyota Corolla 4 1
## Toyota Corona 3 1
## Dodge Challenger 3 2
## AMC Javelin 3 2
## Camaro Z28 3 4
## Pontiac Firebird 3 2
## Fiat X1-9 4 1
## Porsche 914-2 5 2
## Lotus Europa 5 2
## Ford Pantera L 5 4
## Ferrari Dino 5 6
## Maserati Bora 5 8
## Volvo 142E 4 2
###mtcars_filtered = filter(mtcars, wt > 1.5) mtcars_grouped = group_by(mtcars_filtered, cyl) summarise(mtcars_grouped, mn = mean(mpg), sd = sd(mpg)) (Explica que resultado obtienes ?) #### PROCEDIMIENTO
mtcars_filtered = filter(mtcars, wt > 1.5)
mtcars_grouped = group_by(mtcars_filtered, cyl)
summarise(mtcars_grouped, mn = mean(mpg), sd = sd(mpg))
## # A tibble: 3 × 3
## cyl mn sd
## <dbl> <dbl> <dbl>
## 1 4 26.7 4.51
## 2 6 19.7 1.45
## 3 8 15.1 2.56
Explicación: Se obtiene la media y la desviación estándar de la columna mpg, agrupagas según su cilindraje y siempre y cuando su wt sea mayor a 1.5.
###Utilizando pipes ejecuta el ejercicio 17 #### PROCEDIMIENTO
mtcars %>%
filter(wt>1.5) %>%
group_by(cyl) %>%
summarise(mn = mean(mpg), sd = sd(mpg))
## # A tibble: 3 × 3
## cyl mn sd
## <dbl> <dbl> <dbl>
## 1 4 26.7 4.51
## 2 6 19.7 1.45
## 3 8 15.1 2.56
###Es obligatorio utilizar las funciones del paquete
dplyr y recomendable utilizar pipes %>%
para los siguientes ejercicios #### PROCEDIMIENTO
install.packages("dplyr")
## Warning: package 'dplyr' is in use and will not be installed
library(dplyr)
EJERCICIO 20
vuelos.csv situado en
http://gauss.inf.um.es/datos/url<-("http://gauss.inf.um.es/datos/vuelos.csv")
url
## [1] "http://gauss.inf.um.es/datos/vuelos.csv"
EJERCICIO 21
vuelosdestino<-"C:\\Users\\qnoem\\OneDrive\\Documentos\\PROGRAMACION II\\vuelos.csv"
download.file(url,destino)
vuelos<-read.csv(destino,header = T,sep = ",")
head(vuelos)
## date hour minute dep arr dep_delay arr_delay carrier flight dest
## 1 2011-01-01 14 0 1400 1500 0 -10 AA 428 DFW
## 2 2011-01-02 14 1 1401 1501 1 -9 AA 428 DFW
## 3 2011-01-03 13 52 1352 1502 -8 -8 AA 428 DFW
## 4 2011-01-04 14 3 1403 1513 3 3 AA 428 DFW
## 5 2011-01-05 14 5 1405 1507 5 -3 AA 428 DFW
## 6 2011-01-06 13 59 1359 1503 -1 -7 AA 428 DFW
## plane cancelled time dist
## 1 N576AA 0 40 224
## 2 N557AA 0 45 224
## 3 N541AA 0 48 224
## 4 N403AA 0 39 224
## 5 N492AA 0 44 224
## 6 N262AA 0 45 224
EJERCICIO 22
SFO u
OAKutilizando las funciones del paquete dplyr. ¿Con cuantos
vuelos nos quedamos?**SFO_OAK<-(filter(vuelos,(dest=="SFO"|dest=="OAK")))
head(SFO_OAK)
## date hour minute dep arr dep_delay arr_delay carrier flight dest
## 373 2011-01-31 8 51 851 1052 1 -27 CO 170 SFO
## 389 2011-01-31 11 29 1129 1351 4 1 CO 270 SFO
## 402 2011-01-31 14 32 1432 1656 7 5 CO 370 SFO
## 436 2011-01-31 17 48 1748 2001 3 -4 CO 570 SFO
## 467 2011-01-31 21 43 2143 2338 50 24 CO 770 SFO
## 468 2011-01-31 7 29 729 1002 -1 2 CO 771 SFO
## plane cancelled time dist
## 373 N35407 0 225 1635
## 389 N37420 0 228 1635
## 402 N27213 0 229 1635
## 436 N75436 0 236 1635
## 467 N37281 0 224 1635
## 468 N26226 0 237 1635
EJERCICIO 23
vuelos%>%select(dest, dep_delay)%>%
filter(dep_delay >60)%>%
group_by(dest)%>%
summarise(destino_retraso= n_distinct(dep_delay))%>%head
## # A tibble: 6 × 2
## dest destino_retraso
## <chr> <int>
## 1 ABQ 28
## 2 AEX 13
## 3 AMA 11
## 4 ASE 6
## 5 ATL 105
## 6 AUS 49
EJERCICIO 24
select para seleccionar las variables relacionadas con los
retrasos (delay)select(vuelos, dep_delay, arr_delay)%>%head
## dep_delay arr_delay
## 1 0 -10
## 2 1 -9
## 3 -8 -8
## 4 3 3
## 5 5 -3
## 6 -1 -7
select(vuelos, date, dep_delay)%>%head
## date dep_delay
## 1 2011-01-01 0
## 2 2011-01-02 1
## 3 2011-01-03 -8
## 4 2011-01-04 3
## 5 2011-01-05 5
## 6 2011-01-06 -1
select(vuelos, date, arr_delay)%>%head
## date arr_delay
## 1 2011-01-01 -10
## 2 2011-01-02 -9
## 3 2011-01-03 -8
## 4 2011-01-04 3
## 5 2011-01-05 -3
## 6 2011-01-06 -7
select(vuelos, dest, dep_delay)%>%head
## dest dep_delay
## 1 DFW 0
## 2 DFW 1
## 3 DFW -8
## 4 DFW 3
## 5 DFW 5
## 6 DFW -1
EJERCICIO 25
vuelos%>%
select(date,hour,minute,dep_delay)%>%
group_by(date)%>%
summarise(media= mean(dep_delay, na.rm=T),
mediana= median(dep_delay, na.rm=T),
cuartil_75= quantile(dep_delay, 0.75, na.rm=T))%>%head
## # A tibble: 6 × 4
## date media mediana cuartil_75
## <chr> <dbl> <dbl> <dbl>
## 1 2011-01-01 10.7 3 15
## 2 2011-01-02 15.7 7 20
## 3 2011-01-03 13.4 4 18
## 4 2011-01-04 11.9 5 18
## 5 2011-01-05 6.33 1 8.5
## 6 2011-01-06 5.28 0 7
EJERCICIO 26
vuelos%>%select(dep_delay, date, hour, flight)%>%
filter(flight> 10)%>%
group_by(date)%>%
summarise(media_retraso= mean(dep_delay, na.rm=T),
cantidad_vuelos= n_distinct(flight))%>%head
## # A tibble: 6 × 3
## date media_retraso cantidad_vuelos
## <chr> <dbl> <int>
## 1 2011-01-01 10.6 531
## 2 2011-01-02 15.7 649
## 3 2011-01-03 13.6 668
## 4 2011-01-04 12.0 554
## 5 2011-01-05 6.42 561
## 6 2011-01-06 5.34 629
EJERCICIO 27
#install.packages("RMySQL")
#library(RMySQL)
#conexion<- odbcConnect("DATABASE", uid= "root", pwd= "root")
#vuelos1<- sqlQuery(conexion, "SELECT * FROM programacion_vuelos1")
#head(vuelos1)