library(ggplot2)
data("midwest", package = "ggplot2")
theme_set(theme_bw())

gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest")

plot(gg)


gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) +
    xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(title = "Area Vs Population", y = "Population", x = "Area",
         caption = "Source: midwest")

gg + theme(
    plot.title = element_text(
        size = 20, face = "bold", family = "Comic Sans MS",
        color = "tomato", hjust = 0.5, lineheight = 1.2), # title
    plot.subtitle = element_text(size = 15, face = "bold", hjust = 0.5), # subtitle
    plot.caption = element_text(size = 15, family = "serif"), # caption
    axis.title.x = element_text(vjust = 10, size = 15), # X axis title
    axis.title.y = element_text(size = 15), # Y axis title
    axis.text.x = element_text(size = 10, angle = 30, vjust = .5), # X axis text
    axis.text.y = element_text(size = 10))  # Y axis text


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(
        title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest"
    )

gg + labs(color = "State", size = "Density")  # modify legend title

# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(
        title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest"
    )
gg <- gg + guides(color = guide_legend("State"), size = guide_legend("Density"))  # modify legend title

plot(gg)


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(
        title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest"
    )

# Modify Legend
gg + scale_color_discrete(name = "State") +
    scale_size_continuous(name = "Density", guide = FALSE)  # turn off legend for size


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(
        title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest"
    )

# Modify Legend
gg + scale_color_discrete(name = "State", guide = FALSE) +   # turn off legend for color
    scale_size_continuous(name = "Density")


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(
        title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest")

gg + scale_color_manual(
    name = "State",
    labels = c("Illinois",
               "Indiana",
               "Michigan",
               "Ohio",
               "Wisconsin"),
    values = c(
        "IL" = "blue",
        "IN" = "red",
        "MI" = "green",
        "OH" = "brown",
        "WI" = "orange"))


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(
        title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest")

gg + guides(colour = guide_legend(order = 2),
            size = guide_legend(order = 1))


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(
        title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest")

gg + theme(legend.title = element_text(size = 12, color = "firebrick"),
    legend.text = element_text(size = 10),
    legend.key = element_rect(fill = 'springgreen')) +
    guides(colour = guide_legend(override.aes = list(size = 2, stroke =1.5)))


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest")

# No legend
gg + theme(legend.position = "None") +
    labs(subtitle = "No Legend")

# Legend to the left
gg + theme(legend.position="left") +
    labs(subtitle="Legend on the Left")

# legend at the bottom and horizontal
gg + theme(legend.position = "bottom", legend.box = "horizontal") +
    labs(subtitle = "Legend at Bottom")

# legend at bottom-right, inside the plot
gg + theme(legend.title = element_text(size = 12, color = "salmon", face = "bold"),
    legend.justification = c(1, 0),
    legend.position = c(0.95, 0.05),
    legend.background = element_blank(),
    legend.key = element_blank()) +
    labs(subtitle = "Legend: Bottom-Right Inside the Plot")

# legend at top-left, inside the plot
gg + theme(legend.title = element_text(size = 12, color = "salmon", face = "bold"),
    legend.justification = c(0, 1),
    legend.position = c(0.05, 0.95),
    legend.background = element_blank(),
    legend.key = element_blank()) +
    labs(subtitle = "Legend: Top-Left Inside the Plot")

library("tidyverse")
midwest_sub <- midwest %>%
    dplyr::filter(poptotal > 300000) %>%
    dplyr::mutate(large_county = dplyr::if_else(.$poptotal > 300000, .$county, ""))

# Base Plot
gg <- ggplot(midwest, aes(x=area, y=poptotal)) +
    geom_point(aes(col=state, size=popdensity)) +
    geom_smooth(method="loess", se=F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(title="Area Vs Population", y="Population", x="Area", caption="Source: midwest")

# Plot text and label
gg + geom_text(aes(label = large_county), size = 2, data = midwest_sub) +
    labs(subtitle = "With ggplot2::geom_text") +
    theme(legend.position = "None")   # text

gg + geom_label(aes(label = large_county), size = 2, data = midwest_sub,alpha = 0.25) +
    labs(subtitle = "With ggplot2::geom_label") +
    theme(legend.position = "None")  # label

# Plot text and label that REPELS eachother (using ggrepel pkg)
library("ggrepel")
gg + geom_text_repel(aes(label = large_county), size = 2, data = midwest_sub) +
    labs(subtitle = "With ggrepel::geom_text_repel") +
    theme(legend.position = "None")   # text

gg + geom_label_repel(aes(label = large_county), size = 2, data = midwest_sub) +
    labs(subtitle = "With ggrepel::geom_label_repel") +
    theme(legend.position = "None")   # label

gg <- ggplot(midwest, aes(x=area, y=poptotal)) +
    geom_point(aes(col=state, size=popdensity)) +
    geom_smooth(method="loess", se=F) + xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(title="Area Vs Population", y="Population", x="Area", caption="Source: midwest")

# Define and add annotation
library(grid)
my_text <- "This text is at x=0.7 and y=0.8!"
my_grob = grid.text(my_text, x=0.7,  y=0.8,
                    gp=gpar(col="firebrick", fontsize=14, fontface="bold"))
gg + annotation_custom(my_grob)


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) +
    xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest",
        subtitle = "X and Y axis Flipped") +
    theme(legend.position = "None")
# Flip the X and Y axis
gg + coord_flip()


# Base Plot
gg <- ggplot(midwest, aes(x = area, y = poptotal)) +
    geom_point(aes(col = state, size = popdensity)) +
    geom_smooth(method = "loess", se = F) +
    xlim(c(0, 0.1)) + ylim(c(0, 500000)) +
    labs(title = "Area Vs Population",
        y = "Population",
        x = "Area",
        caption = "Source: midwest",
        subtitle = "Axis Scales Reversed") +
    theme(legend.position = "None")

# Reverse the X and Y Axis
gg + scale_x_reverse() + scale_y_reverse()


data(mpg, package = "ggplot2")  # load data

g <- ggplot(mpg, aes(x = displ, y = hwy)) +
    geom_point() +
    labs(title = "hwy vs displ", caption = "Source: mpg") +
    geom_smooth(method = "lm", se = FALSE) +
    theme_bw()  # apply bw theme
plot(g)

# Base Plot
g <- ggplot(mpg, aes(x = displ, y = hwy)) +
    geom_point() +
    geom_smooth(method = "lm", se = FALSE) +
    theme_bw()  # apply bw theme

# Facet wrap with common scales
g + facet_wrap(~ class, nrow = 3) +
    labs(title = "hwy vs displ",
    caption = "Source: mpg",
    subtitle = "Ggplot2 - Faceting - Multiple plots in one figure")  # Shared scales

# Facet wrap with free scales
g + facet_wrap(~ class, scales = "free") +
    labs(title = "hwy vs displ",
    caption = "Source: mpg",
    subtitle = "Ggplot2 - Faceting - Multiple plots in one figure with free scales")  # Scales free

# Base Plot
g <- ggplot(mpg, aes(x = displ, y = hwy)) +
    geom_point() +
    labs(title = "hwy vs displ",
         caption = "Source: mpg",
         subtitle = "Ggplot2 - Faceting - Multiple plots in one figure") +
    geom_smooth(method = "lm", se = FALSE) +
    theme_bw()  # apply bw theme

# Add Facet Grid
g1 <- g + facet_grid(manufacturer ~ class)  # manufacturer in rows and class in columns
plot(g1)

# Base Plot
g <- ggplot(mpg, aes(x = displ, y = hwy)) +
    geom_point() +
    geom_smooth(method = "lm", se = FALSE) +
    labs(title = "hwy vs displ",
         caption = "Source: mpg",
         subtitle = "Ggplot2 - Facet Grid - Multiple plots in one figure") +
    theme_bw()  # apply bw theme

# Add Facet Grid
g2 <- g + facet_grid(cyl ~ class)  # cyl in rows and class in columns.
plot(g2)

# Draw Multiple plots in same figure.
library("gridExtra")
gridExtra::grid.arrange(g1, g2, ncol=2)


g <- ggplot(mpg, aes(x = displ, y = hwy)) +
    geom_point() +
    geom_smooth(method = "lm", se = FALSE) +
    theme_bw()  # apply bw theme

# Change Plot Background elements
g + theme(
    panel.background = element_rect(fill = 'khaki'),
    panel.grid.major = element_line(colour = "burlywood", size = 1.5),
    panel.grid.minor = element_line(colour = "tomato", size = .25,
                                    linetype = "dashed"),
    panel.border = element_blank(),
    axis.line.x = element_line(colour = "darkorange", size = 1.5,
                               lineend = "butt"),
    axis.line.y = element_line(colour = "darkorange", size = 1.5)
    ) + labs(title = "Modified Background",
             subtitle = "How to Change Major and Minor grid, Axis Lines, No Border")

# Change Plot Margins
g + theme(plot.background = element_rect(fill = "salmon"),
          plot.margin = unit(c(2, 2, 1, 1), "cm")) +  # top, right, bottom, left
    labs(title = "Modified Background", subtitle = "How to Change Plot Margin")


# Base Plot
g <- ggplot(mpg, aes(x = displ, y = hwy)) +
    geom_point() +
    geom_smooth(method = "lm", se = FALSE) +
    theme_bw()  # apply bw theme

g + theme(
    panel.grid.major = element_blank(),
    panel.grid.minor = element_blank(),
    panel.border = element_blank(),
    axis.title = element_blank(),
    axis.text = element_blank(),
    axis.ticks = element_blank()
) + labs(title = "Modified Background",
         subtitle = "How to remove major and minor axis grid, border, axis title, text and ticks")


library("grid")
library("png")

img <- readPNG(system.file("img", "Rlogo.png", package="png"))
# source: https://www.r-project.org/
g_pic <- rasterGrob(img, interpolate = TRUE)

# Base Plot
g <- ggplot(mpg, aes(x = displ, y = hwy)) +
    geom_point() +
    geom_smooth(method = "lm", se = FALSE) +
    theme_bw()  # apply bw theme

g + theme(
    panel.grid.major = element_blank(),
    panel.grid.minor = element_blank(),
    plot.title = element_text(size = rel(1.5), face = "bold"),
    axis.ticks = element_blank()) +
    annotation_custom(g_pic, xmin = 5, xmax = 7,
                      ymin = 30, ymax = 45)