class: center, middle, inverse, title-slide .title[ # Basics of R Programming ] .author[ ### <br><br>Thiyanga S. Talagala, University of Sri Jayewardenepura ] .date[ ### IASSL - May 25/28, 2023 ] --- <style type="text/css"> .remark-slide-content { font-size: 35px; } </style> <style type="text/css"> .remark-slide-content { font-size: 35px; } </style> <style> p.comment { background-color: #DBDBDB; padding: 10px; border: 1px solid black; margin-left: 25px; border-radius: 5px; font-style: italic; } </style> <style type="text/css"> h1, #TOC>ul>li { color: #1b9e77; font-weight: bold; } h2, #TOC>ul>ul>li { color: #1b9e77; #font-family: "Times"; font-weight: bold; } h3, #TOC>ul>ul>li { color: #00441b; #font-family: "Times"; font-weight: bold; } </style> .pull-left[ ## Data structures Way to **store and organize data** so that it can be used efficiently. ```r marks <- c(100, 40, 34, 97, 98) marks ``` ``` [1] 100 40 34 97 98 ``` ] -- .pull-right[ ## Functions Tell R to **do something** ```r mean(marks) ``` ``` [1] 73.8 ``` ```r summary(marks) ``` ``` Min. 1st Qu. Median Mean 3rd Qu. Max. 34.0 40.0 97.0 73.8 98.0 100.0 ``` ] --- ## Data structures <img src="ds.png" width="80%" /> Source: Ceballos and Cardiel, 2013 --- Longer version is available at: https://r4fun.netlify.app/blog/topic5/ --- ## Required R package ```r library(tidyverse) ``` ``` ── Attaching packages ─────────────────────────────────────── tidyverse 1.3.2 ── ✔ ggplot2 3.4.1 ✔ purrr 1.0.1 ✔ tibble 3.2.1 ✔ dplyr 1.1.2 ✔ tidyr 1.3.0 ✔ stringr 1.5.0 ✔ readr 2.1.3 ✔ forcats 1.0.0 ── Conflicts ────────────────────────────────────────── tidyverse_conflicts() ── ✖ dplyr::filter() masks stats::filter() ✖ dplyr::lag() masks stats::lag() ``` --- ## iris dataset  ---  --- ```r iris ``` ``` Sepal.Length Sepal.Width Petal.Length Petal.Width Species 1 5.1 3.5 1.4 0.2 setosa 2 4.9 3.0 1.4 0.2 setosa 3 4.7 3.2 1.3 0.2 setosa 4 4.6 3.1 1.5 0.2 setosa 5 5.0 3.6 1.4 0.2 setosa 6 5.4 3.9 1.7 0.4 setosa 7 4.6 3.4 1.4 0.3 setosa 8 5.0 3.4 1.5 0.2 setosa 9 4.4 2.9 1.4 0.2 setosa 10 4.9 3.1 1.5 0.1 setosa 11 5.4 3.7 1.5 0.2 setosa 12 4.8 3.4 1.6 0.2 setosa 13 4.8 3.0 1.4 0.1 setosa 14 4.3 3.0 1.1 0.1 setosa 15 5.8 4.0 1.2 0.2 setosa 16 5.7 4.4 1.5 0.4 setosa 17 5.4 3.9 1.3 0.4 setosa 18 5.1 3.5 1.4 0.3 setosa 19 5.7 3.8 1.7 0.3 setosa 20 5.1 3.8 1.5 0.3 setosa 21 5.4 3.4 1.7 0.2 setosa 22 5.1 3.7 1.5 0.4 setosa 23 4.6 3.6 1.0 0.2 setosa 24 5.1 3.3 1.7 0.5 setosa 25 4.8 3.4 1.9 0.2 setosa 26 5.0 3.0 1.6 0.2 setosa 27 5.0 3.4 1.6 0.4 setosa 28 5.2 3.5 1.5 0.2 setosa 29 5.2 3.4 1.4 0.2 setosa 30 4.7 3.2 1.6 0.2 setosa 31 4.8 3.1 1.6 0.2 setosa 32 5.4 3.4 1.5 0.4 setosa 33 5.2 4.1 1.5 0.1 setosa 34 5.5 4.2 1.4 0.2 setosa 35 4.9 3.1 1.5 0.2 setosa 36 5.0 3.2 1.2 0.2 setosa 37 5.5 3.5 1.3 0.2 setosa 38 4.9 3.6 1.4 0.1 setosa 39 4.4 3.0 1.3 0.2 setosa 40 5.1 3.4 1.5 0.2 setosa 41 5.0 3.5 1.3 0.3 setosa 42 4.5 2.3 1.3 0.3 setosa 43 4.4 3.2 1.3 0.2 setosa 44 5.0 3.5 1.6 0.6 setosa 45 5.1 3.8 1.9 0.4 setosa 46 4.8 3.0 1.4 0.3 setosa 47 5.1 3.8 1.6 0.2 setosa 48 4.6 3.2 1.4 0.2 setosa 49 5.3 3.7 1.5 0.2 setosa 50 5.0 3.3 1.4 0.2 setosa 51 7.0 3.2 4.7 1.4 versicolor 52 6.4 3.2 4.5 1.5 versicolor 53 6.9 3.1 4.9 1.5 versicolor 54 5.5 2.3 4.0 1.3 versicolor 55 6.5 2.8 4.6 1.5 versicolor 56 5.7 2.8 4.5 1.3 versicolor 57 6.3 3.3 4.7 1.6 versicolor 58 4.9 2.4 3.3 1.0 versicolor 59 6.6 2.9 4.6 1.3 versicolor 60 5.2 2.7 3.9 1.4 versicolor 61 5.0 2.0 3.5 1.0 versicolor 62 5.9 3.0 4.2 1.5 versicolor 63 6.0 2.2 4.0 1.0 versicolor 64 6.1 2.9 4.7 1.4 versicolor 65 5.6 2.9 3.6 1.3 versicolor 66 6.7 3.1 4.4 1.4 versicolor 67 5.6 3.0 4.5 1.5 versicolor 68 5.8 2.7 4.1 1.0 versicolor 69 6.2 2.2 4.5 1.5 versicolor 70 5.6 2.5 3.9 1.1 versicolor 71 5.9 3.2 4.8 1.8 versicolor 72 6.1 2.8 4.0 1.3 versicolor 73 6.3 2.5 4.9 1.5 versicolor 74 6.1 2.8 4.7 1.2 versicolor 75 6.4 2.9 4.3 1.3 versicolor 76 6.6 3.0 4.4 1.4 versicolor 77 6.8 2.8 4.8 1.4 versicolor 78 6.7 3.0 5.0 1.7 versicolor 79 6.0 2.9 4.5 1.5 versicolor 80 5.7 2.6 3.5 1.0 versicolor 81 5.5 2.4 3.8 1.1 versicolor 82 5.5 2.4 3.7 1.0 versicolor 83 5.8 2.7 3.9 1.2 versicolor 84 6.0 2.7 5.1 1.6 versicolor 85 5.4 3.0 4.5 1.5 versicolor 86 6.0 3.4 4.5 1.6 versicolor 87 6.7 3.1 4.7 1.5 versicolor 88 6.3 2.3 4.4 1.3 versicolor 89 5.6 3.0 4.1 1.3 versicolor 90 5.5 2.5 4.0 1.3 versicolor 91 5.5 2.6 4.4 1.2 versicolor 92 6.1 3.0 4.6 1.4 versicolor 93 5.8 2.6 4.0 1.2 versicolor 94 5.0 2.3 3.3 1.0 versicolor 95 5.6 2.7 4.2 1.3 versicolor 96 5.7 3.0 4.2 1.2 versicolor 97 5.7 2.9 4.2 1.3 versicolor 98 6.2 2.9 4.3 1.3 versicolor 99 5.1 2.5 3.0 1.1 versicolor 100 5.7 2.8 4.1 1.3 versicolor 101 6.3 3.3 6.0 2.5 virginica 102 5.8 2.7 5.1 1.9 virginica 103 7.1 3.0 5.9 2.1 virginica 104 6.3 2.9 5.6 1.8 virginica 105 6.5 3.0 5.8 2.2 virginica 106 7.6 3.0 6.6 2.1 virginica 107 4.9 2.5 4.5 1.7 virginica 108 7.3 2.9 6.3 1.8 virginica 109 6.7 2.5 5.8 1.8 virginica 110 7.2 3.6 6.1 2.5 virginica 111 6.5 3.2 5.1 2.0 virginica 112 6.4 2.7 5.3 1.9 virginica 113 6.8 3.0 5.5 2.1 virginica 114 5.7 2.5 5.0 2.0 virginica 115 5.8 2.8 5.1 2.4 virginica 116 6.4 3.2 5.3 2.3 virginica 117 6.5 3.0 5.5 1.8 virginica 118 7.7 3.8 6.7 2.2 virginica 119 7.7 2.6 6.9 2.3 virginica 120 6.0 2.2 5.0 1.5 virginica 121 6.9 3.2 5.7 2.3 virginica 122 5.6 2.8 4.9 2.0 virginica 123 7.7 2.8 6.7 2.0 virginica 124 6.3 2.7 4.9 1.8 virginica 125 6.7 3.3 5.7 2.1 virginica 126 7.2 3.2 6.0 1.8 virginica 127 6.2 2.8 4.8 1.8 virginica 128 6.1 3.0 4.9 1.8 virginica 129 6.4 2.8 5.6 2.1 virginica 130 7.2 3.0 5.8 1.6 virginica 131 7.4 2.8 6.1 1.9 virginica 132 7.9 3.8 6.4 2.0 virginica 133 6.4 2.8 5.6 2.2 virginica 134 6.3 2.8 5.1 1.5 virginica 135 6.1 2.6 5.6 1.4 virginica 136 7.7 3.0 6.1 2.3 virginica 137 6.3 3.4 5.6 2.4 virginica 138 6.4 3.1 5.5 1.8 virginica 139 6.0 3.0 4.8 1.8 virginica 140 6.9 3.1 5.4 2.1 virginica 141 6.7 3.1 5.6 2.4 virginica 142 6.9 3.1 5.1 2.3 virginica 143 5.8 2.7 5.1 1.9 virginica 144 6.8 3.2 5.9 2.3 virginica 145 6.7 3.3 5.7 2.5 virginica 146 6.7 3.0 5.2 2.3 virginica 147 6.3 2.5 5.0 1.9 virginica 148 6.5 3.0 5.2 2.0 virginica 149 6.2 3.4 5.4 2.3 virginica 150 5.9 3.0 5.1 1.8 virginica ``` --- ```r summary(iris) ``` ``` Sepal.Length Sepal.Width Petal.Length Petal.Width Min. :4.300 Min. :2.000 Min. :1.000 Min. :0.100 1st Qu.:5.100 1st Qu.:2.800 1st Qu.:1.600 1st Qu.:0.300 Median :5.800 Median :3.000 Median :4.350 Median :1.300 Mean :5.843 Mean :3.057 Mean :3.758 Mean :1.199 3rd Qu.:6.400 3rd Qu.:3.300 3rd Qu.:5.100 3rd Qu.:1.800 Max. :7.900 Max. :4.400 Max. :6.900 Max. :2.500 Species setosa :50 versicolor:50 virginica :50 ``` --- # Some useful functions .pull-left[ ```r mean(iris$Sepal.Length) ``` ``` [1] 5.843333 ``` ```r median(iris$Sepal.Width) ``` ``` [1] 3 ``` ```r sd(iris$Sepal.Length) ``` ``` [1] 0.8280661 ``` ] .pull-right[ ```r sum(iris$Sepal.Length) ``` ``` [1] 876.5 ``` ```r length(iris$Sepal.Length) ``` ``` [1] 150 ``` ] --- # Inputs to a function .pull-left[ ```r head(iris) ``` ``` Sepal.Length Sepal.Width Petal.Length Petal.Width Species 1 5.1 3.5 1.4 0.2 setosa 2 4.9 3.0 1.4 0.2 setosa 3 4.7 3.2 1.3 0.2 setosa 4 4.6 3.1 1.5 0.2 setosa 5 5.0 3.6 1.4 0.2 setosa 6 5.4 3.9 1.7 0.4 setosa ``` ```r head(iris, 3) ``` ``` Sepal.Length Sepal.Width Petal.Length Petal.Width Species 1 5.1 3.5 1.4 0.2 setosa 2 4.9 3.0 1.4 0.2 setosa 3 4.7 3.2 1.3 0.2 setosa ``` ] .pull-right[  ] --- # Data visualisation ```r library(tidyverse) ``` ```r ggplot(iris, aes(x=Sepal.Length, y=Sepal.Width, col=Species)) + geom_point() ``` <img src="5_basics_IASSL_files/figure-html/unnamed-chunk-12-1.png" width="100%" /> --- # Help file .pull-left[ ```r ?mean help(mean) ``` ] .pull-right[ <img src="help.png" width="170%" /> ] --- # Commenting ```r mean(iris$Sepal.Length, na.rm=TRUE) # compute mean of SL ``` ``` [1] 5.843333 ``` --- ## Pipe operator (`|>`) .pull-left[ ```r mean(iris$Sepal.Length) ``` ``` [1] 5.843333 ``` ```r mean(iris$Sepal.Length, na.rm=TRUE) ``` ``` [1] 5.843333 ``` ] .pull-right[ ```r library(magrittr) iris$Sepal.Length |> mean() ``` ``` [1] 5.843333 ``` ```r iris$Sepal.Length |> mean(na.rm=TRUE) ``` ``` [1] 5.843333 ``` ] --- ## Another Version Pipe operator (`%>%`) .pull-left[ ```r mean(iris$Sepal.Length) ``` ``` [1] 5.843333 ``` ```r mean(iris$Sepal.Length, na.rm=TRUE) ``` ``` [1] 5.843333 ``` ] .pull-right[ ```r library(magrittr) iris$Sepal.Length %>% mean() ``` ``` [1] 5.843333 ``` ```r iris$Sepal.Length %>% mean(na.rm=TRUE) ``` ``` [1] 5.843333 ``` ] --- ## Pipe operator (`%>%`)  --- ## Built-in dataset ```r library(palmerpenguins) data(penguins) head(penguins) ``` ``` # A tibble: 6 × 8 species island bill_length_mm bill_depth_mm flipper_length_mm body_mass_g <fct> <fct> <dbl> <dbl> <int> <int> 1 Adelie Torgersen 39.1 18.7 181 3750 2 Adelie Torgersen 39.5 17.4 186 3800 3 Adelie Torgersen 40.3 18 195 3250 4 Adelie Torgersen NA NA NA NA 5 Adelie Torgersen 36.7 19.3 193 3450 6 Adelie Torgersen 39.3 20.6 190 3650 # ℹ 2 more variables: sex <fct>, year <int> ``` --- ## Skim data ```r library(skimr) skim(penguins) ``` --- # Recap ✅ Data structures and functions ✅ Working with packages ✅ Functions in R ✅ Help file ✅ Commenting