Assignment 02

R Markdown

head(mtcars)

##                    mpg cyl disp  hp drat    wt  qsec vs am gear carb
## Mazda RX4         21.0   6  160 110 3.90 2.620 16.46  0  1    4    4
## Mazda RX4 Wag     21.0   6  160 110 3.90 2.875 17.02  0  1    4    4
## Datsun 710        22.8   4  108  93 3.85 2.320 18.61  1  1    4    1
## Hornet 4 Drive    21.4   6  258 110 3.08 3.215 19.44  1  0    3    1
## Hornet Sportabout 18.7   8  360 175 3.15 3.440 17.02  0  0    3    2
## Valiant           18.1   6  225 105 2.76 3.460 20.22  1  0    3    1

# Load library
library(ggplot2)

## Warning: package 'ggplot2' was built under R version 4.4.3

# Plot
ggplot(mtcars, aes(x = hp, y = mpg, color = factor(cyl), shape = factor(cyl))) +
  geom_point(size = 3) +  # Size and shape of points
  scale_x_continuous(name = "Horsepower (hp)", breaks = seq(50, 350, 50)) +  # X-axis
  scale_y_continuous(name = "Miles per Gallon (mpg)", breaks = seq(10, 35, 5)) +  # Y-axis
  labs(
    title = "Relationship Between Horsepower and Fuel Efficiency",
    subtitle = "Scatter plot using mtcars dataset",
    caption = "Source: Motor Trend US magazine (1974)",
    color = "Number of Cylinders",
    shape = "Number of Cylinders"
  ) +
  # Custom colors for each cylinder category
  scale_color_manual(values = c("4" = "steelblue", "6" = "forestgreen", "8" = "firebrick")) +
  # Clean minimal theme with enhancements
  theme_minimal(base_size = 14) +
  theme(
    plot.title = element_text(face = "bold", size = 16, color = "darkblue"),
    plot.subtitle = element_text(size = 12, face = "italic"),
    axis.title = element_text(size = 13),
    axis.text = element_text(size = 11),
    legend.position = "bottom"
  )