Figures functions

figures <- function(data, group = NULL)
{
  if (is.null(group))
  {
    names(data) %>%
      map(. %>%
      {
        ggplot(data) +
          aes_(x  = as.name(.)) -> g
        if (is.factor(data[[.]]))
        {
          g <- g +
            geom_bar() +
            ylab("Nombre") +
            theme(axis.text.x = element_text(angle = -45, vjust = 1, hjust = 0))
        } else
        {
          g <- g +
            geom_histogram(aes(y = ..density..)) +
            geom_density() +
            ylab("Proportion")
        }
      }) -> plots
    names(plots) <- names(data)
    
    plots
  } else
  {
    names(data) %>%
      map(. %>%
      {
        ggplot(data) +
          aes_(x  = as.name(.)) -> g
        if (is.factor(data[[.]]))
        {
          g <- g +
            geom_bar(aes_string(fill = group), position = "dodge") +
            ylab("Nombre") +
            theme(axis.text.x = element_text(angle = -45, vjust = 1, hjust = 0))
        } else
        {
          g <- g +
            aes_(fill = as.name(group)) +
            geom_histogram(aes(y = ..density..), position = "dodge") +
            geom_density(alpha = .5) +
            ylab("Proportion")
        }
      }) -> plots
    names(plots) <- names(data)
    
    plots
  }
}

save_figures <- function(plots, path)
{
  dir.create(path, showWarnings = F, recursive = T)
  names(plots) %>%
    map( . %>% {ggsave(plot = plots[[.]], filename = str_c(path, str_replace_all(., "/", "-"), ".png"))})
}

df %>% figures -> figs_univarié
df %>% figures("grouping_variable") -> figs_par_groupe
figs %>% save_figures