A line plot represents values or trends across ordered positions by connecting plotted points with line segments. In R, ggplot2 combines geom_line() with geom_point() when both the trend and the individual observations matter. section 13.4 section 16.3
Build a useful line plot by:
- Preparing one row per ordered position, such as season, trial, streak length, or independent trial count. section 13.4 section 16.4.2
- Mapping the ordered variable to x and the measured value to y, then setting group = 1 when the data contain one series. section 16.3 section 16.4.2
- Adding geom_line() for the connected trend and geom_point() for visible observations; adjust size, color, labels, axes, and themes for readability. section 13.4 section 16.3
- Interpreting the shape rather than merely reading values: a curve can reveal increasing values at a decreasing rate, irregular variation, or a trend that does not match a reference pattern. section 16.3 section 16.4.2
Plot a probability curve
After calculating Laplace probabilities, map independent_trials to x and laplace to y: ggplot(df, aes(x = independent_trials, y = laplace, group = 1)) + geom_line(color = "purple", size = 1.5) + geom_point(size = 3, color = "purple"). The resulting plot shows probability increasing at a decreasing rate without reaching 100%. section 16.3
ggplot(ws_gini_summary, aes(x = Year, y = gc, group = 1)) +
geom_line(aes(y = gc), color = "black", size = .5) +
geom_point(size = 5, color = "seagreen3") +
geom_text(aes(label = gc),
nudge_x = 0.01, nudge_y = 0.01,
check_overlap = TRUE, size = 2.5) +
labs(title = "Gini Coefficient for Win Shares",
subtitle = "1991-2017",
x = "Season",
y = "Gini Coeffiicient",
caption = "includes a maximum top 14 win shares for each team") +
ylim(0.42, 0.60) +
theme(plot.title = element_text(hjust = 0.5, face = "bold")) +
theme(plot.subtitle = element_text(hjust = 0.5)) +
theme(axis.text.x = element_text(angle = 45, hjust = 1)) +
annotate("rect", xmin = "1991", xmax = "2009",
ymin = 0.42, ymax = 0.60, alpha = 0.1, fill = "orange") +
annotate("rect", xmin = "2010", xmax = "2017",
ymin = 0.42, ymax = 0.60, alpha = 0.1, fill = "blue")
Explore a labeled year-over-year Gini line plot with enlarged points, rotated season labels, adjusted axis limits, and shaded periods. section 13.4
