Repaso introducción a R
Valentina Melo
2023-08-18
Campos en R
# Ctrl + alt + i (chunk R)
# rnorm generador de datos normales
set.seed(123)
rto = rnorm(n = 100, mean = 3, sd = 0.3)
# Redondear
rto = round(rto, digits = 2);rto## [1] 2.83 2.93 3.47 3.02 3.04 3.51 3.14 2.62 2.79 2.87 3.37 3.11 3.12 3.03 2.83
## [16] 3.54 3.15 2.41 3.21 2.86 2.68 2.93 2.69 2.78 2.81 2.49 3.25 3.05 2.66 3.38
## [31] 3.13 2.91 3.27 3.26 3.25 3.21 3.17 2.98 2.91 2.89 2.79 2.94 2.62 3.65 3.36
## [46] 2.66 2.88 2.86 3.23 2.97 3.08 2.99 2.99 3.41 2.93 3.45 2.54 3.18 3.04 3.06
## [61] 3.11 2.85 2.90 2.69 2.68 3.09 3.13 3.02 3.28 3.62 2.85 2.31 3.30 2.79 2.79
## [76] 3.31 2.91 2.63 3.05 2.96 3.00 3.12 2.89 3.19 2.93 3.10 3.33 3.13 2.90 3.34
## [91] 3.30 3.16 3.07 2.81 3.41 2.82 3.66 3.46 2.93 2.69rto2 = c(3.2, 3.4, 3.2, 3.3, 3.4, 3.1, 2.8, 2.2, 2.9, 1.9)
MO = c(10.3, 10.4, 11.3, 12, 9.8, 9.7, 8.9, 10.2, 10, 9.1)
pH = c(7, 6.7, NA, 5, 5.3, 7, 6.3, 8)# Clase
class(pH)## [1] "numeric"# Tamaño de un vector
length(rto)## [1] 100length(rto2)## [1] 10# Indexación
rto[1]## [1] 2.83rto[1:5]## [1] 2.83 2.93 3.47 3.02 3.04rto[length(rto)]## [1] 2.69rto[100]## [1] 2.69# Cambiar valores
rto[100] = 3
rto[100]## [1] 3# Cuál es el máximo
which.max(rto) # Posición## [1] 97rto[which.max(rto)] # valor máximo## [1] 3.66# Diagrama de cajas
boxplot(rto)
# Diagrama de cajas en posición horizontal
boxplot(rto, horizontal = T)
# Vector en escala nominal
gn = c("g1", "g2", "g3", "g4", "g5")
gn## [1] "g1" "g2" "g3" "g4" "g5"class(gn)## [1] "character"# Histograma
hist(rto)
sismo = rexp(n = 100, rate = 0.6)
hist(sismo, ylim = c(0, 50))
boxplot(sismo, horizontal = T)
Importar datos desde excel
- abrir panel ambiente (environment)
- Dar click a importar dataset
- Dar click a la opción de excel
- Buscar el archivo de excel guardado con los datos
- Dar clcick en aceptar (o upload) y asi se cargan los datos
# Crear una matriz
M1 = matrix(data = 1:9, nrow = 3, byrow = T)
M1## [,1] [,2] [,3]
## [1,] 1 2 3
## [2,] 4 5 6
## [3,] 7 8 9# Indexar una matrix
# M1[filas, columnas]
M1[1,]## [1] 1 2 3M1[,3]## [1] 3 6 9M1[2.2]## [1] 4M2 = M1[,-3]
M2## [,1] [,2]
## [1,] 1 2
## [2,] 4 5
## [3,] 7 8# Matrix identidad
v1 = rep(1,5)
v1## [1] 1 1 1 1 1v2= diag(v1)
v2## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 0 0 0 0
## [2,] 0 1 0 0 0
## [3,] 0 0 1 0 0
## [4,] 0 0 0 1 0
## [5,] 0 0 0 0 1# Dataframes
df = data.frame(MO, rto2)
class(df)## [1] "data.frame"df## MO rto2
## 1 10.3 3.2
## 2 10.4 3.4
## 3 11.3 3.2
## 4 12.0 3.3
## 5 9.8 3.4
## 6 9.7 3.1
## 7 8.9 2.8
## 8 10.2 2.2
## 9 10.0 2.9
## 10 9.1 1.9# Dimension del dataframe
dim(df)## [1] 10 2dim(M1)## [1] 3 3df[5,2] = NA
df## MO rto2
## 1 10.3 3.2
## 2 10.4 3.4
## 3 11.3 3.2
## 4 12.0 3.3
## 5 9.8 NA
## 6 9.7 3.1
## 7 8.9 2.8
## 8 10.2 2.2
## 9 10.0 2.9
## 10 9.1 1.9# Eliminando una fila
df2 = df[-1,]
df2## MO rto2
## 2 10.4 3.4
## 3 11.3 3.2
## 4 12.0 3.3
## 5 9.8 NA
## 6 9.7 3.1
## 7 8.9 2.8
## 8 10.2 2.2
## 9 10.0 2.9
## 10 9.1 1.9# Eliminando una columna
df3 = df2[,-2]
df3## [1] 10.4 11.3 12.0 9.8 9.7 8.9 10.2 10.0 9.1df3 = data.frame(MO = df3)
df3$pH = rnorm(9, 6, 0.3)
df3## MO pH
## 1 10.4 6.539142
## 2 11.3 5.756902
## 3 12.0 6.570270
## 4 9.8 6.212686
## 5 9.7 6.220858
## 6 8.9 6.409733
## 7 10.2 5.827121
## 8 10.0 5.758580
## 9 9.1 5.839480df3$Alt = rnorm(9, 100, 1)
df3## MO pH Alt
## 1 10.4 6.539142 100.79155
## 2 11.3 5.756902 99.29239
## 3 12.0 6.570270 98.72446
## 4 9.8 6.212686 102.37546
## 5 9.7 6.220858 98.90641
## 6 8.9 6.409733 100.19244
## 7 10.2 5.827121 99.87384
## 8 10.0 5.758580 98.61157
## 9 9.1 5.839480 100.46990# Cambiando los nombres al dataframe
colnames(df3) = c("N1", "N2", "N3")
df3## N1 N2 N3
## 1 10.4 6.539142 100.79155
## 2 11.3 5.756902 99.29239
## 3 12.0 6.570270 98.72446
## 4 9.8 6.212686 102.37546
## 5 9.7 6.220858 98.90641
## 6 8.9 6.409733 100.19244
## 7 10.2 5.827121 99.87384
## 8 10.0 5.758580 98.61157
## 9 9.1 5.839480 100.46990Escribiendo ecuaciones en latex
\[\LARGE{Latex}\]
\[x=\frac{-b \pm \sqrt{b^2-4ac}}{2a}\]