index.Rmd

---
knit: "bookdown::render_book"
title: "Advanced R Solutions"
author: "Malte Grosser, Henning Bumann & Hadley Wickham"
description: "Solutions to the Exercises from Hadley Wickham's book 'Advanced R'."
date: "(updated on `r Sys.Date()`)"
url: 'https\://advanced-r-solutions.rbind.io/'
github-repo: Tazinho/Advanced-R-Solutions
cover-image: images/advrs_cover.png
site: bookdown::bookdown_site
documentclass: krantz
bibliography: packages.bib
biblio-style: apalike
link-citations: yes
---

`r if (knitr::is_latex_output()) '<!--'` 

# Welcome {-}

```{r global_options, include=FALSE}
knitr::opts_chunk$set(collapse = TRUE)  
```

<img src="images/advrs_cover.png" width="250" height="366" align="right" alt="Cover image" />

This book offers solutions to the exercises from Hadley Wickham's book [Advanced R](https://adv-r.hadley.nz/) (Edition 2). It is work in progress and under active development. The 2nd edition of Advanced R is still being revised, but we hope to provide most of the answers in 2019.

The solutions to the first edition of Advanced R can currently be found at https://advanced-r-solutions-ed1.netlify.com/.

The code for this book can be found on [GitHub](https://github.com/Tazinho/Advanced-R-Solutions.git). Your PRs and suggestions are very welcome. 

## License {-}

<a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/"><img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png" /></a><br />This work by Malte Grosser and Henning Bumann is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>

## Acknowledgements {-}

We would also like to thank everybody else who contributed to this project by fixing typos, grammar or revising exercises: `@3zhang`, `@caijun`, `@dongzhuoer`, `@lotgon`

## Current Progress {-}

```{r, echo = FALSE, cache=FALSE, warning = FALSE, message=FALSE, fig.width = 8, fig.height=10}
library(tibble)
library(dplyr)
library(purrr)
library(tidyr)
library(forcats)
library(ggplot2)

# import from file --------------------------------------------------------
df_long <- read.csv2("progress_data.csv", stringsAsFactors = FALSE, 
                      header = TRUE) %>% 
  as_tibble() %>% 
  modify_at("status", factor, levels = c("open", "started", "solved")) %>% 
  tibble::rowid_to_column("id") %>% 
  separate(chapter, "nr", sep = " ", remove = FALSE, extra = "drop") %>% 
  mutate(nr = as.integer(nr), 
         chapter = factor(chapter),
         chapter = fct_reorder(chapter, nr, .desc = TRUE),
         part = case_when(nr < 9 ~ "Foundations",
                          nr < 12 ~ "FP",
                          nr < 17 ~ "OOP",
                          nr < 22 ~ "Metapr.",
                          TRUE    ~ "Techn."),
         part = factor(part, levels = c("Foundations", "FP", "OOP",
                                        "Metapr.", "Techn.")))

# Intermediate calculations
percent_solved <- mean(df_long$status == "solved", na.rm = TRUE) * 100

# Create Plot
plot_progress <- df_long %>% 
  ggplot(aes(x = chapter, fill = status, group = -id,
             subchapter = subchapter, exercise = exercise,
             credits = credits)) +
  coord_flip() +
  geom_bar(color = "white") +
  scale_y_continuous(expand = c(0, 0)) +
  theme_bw(base_size = 14) +
  theme(legend.position = "bottom",
        # legend.justification = c(0, 1),
        strip.background = element_rect(fill = "#EFEFEF"),
        strip.placement = "outside",
        axis.text.x = element_blank(),
        axis.text.y = element_text(),
        axis.title = element_blank(),
        axis.ticks = element_blank(),
        # plot.title = element_text(hjust = 2.5),
        panel.grid = element_blank(),
        panel.border = element_blank(),
        panel.background = element_blank()) +
  guides(color = FALSE,
         fill = guide_legend(nrow = 1)) +
  scale_fill_manual(values = c("#F99992", "orange", "#00BFC4")) +
  labs(title = paste("Solved Exercises:",
                     round(percent_solved, 1),
                     "% (2nd Edition)"),
       caption = paste0("(Open: ",
                         sum(df_long$status == "open"),
                         " | Started: ",
                         sum(df_long$status == "started"),
                         " | Solved: ",
                         sum(df_long$status == "solved"),
                        ")"),
       fill = "Status:")

# Create static plot (including facets for parts)
plot_progress + 
  facet_grid(part ~ ., scales = "free",
             space = "free", switch = "both")

# Create interactive version of plot
# plot_progress %>%
#   plotly::ggplotly(tooltip = c("subchapter", "exercise", "credits")) %>% 
#   plotly::layout(legend = list(orientation = "h",
#                                xanchor = "left",
#                                x = 0,
#                                yanchor = "bottom",
#                                y = -.05,
#                                font = list(size = 25)))
```


```{r include=FALSE, eval = FALSE}
# automatically create a bib database for R packages
knitr::write_bib(c(.packages(), 'bookdown', 'knitr', 'rmarkdown'),
                 'packages.bib')
```

`r if (knitr::is_latex_output()) '-->'`