3 Cross-references

Cross-references make it easier for your readers to find and link to elements in your book.

3.1 Chapters and sub-chapters

There are two steps to cross-reference any heading:

  1. Label the heading: # Hello world {#nice-label}.
    • Leave the label off if you like the automated heading generated based on your heading title: for example, # Hello world = # Hello world {#hello-world}.
    • To label an un-numbered heading, use: # Hello world {-#nice-label} or {# Hello world .unnumbered}.
  2. Next, reference the labeled heading anywhere in the text using \@ref(nice-label); for example, please see Chapter 3.

3.2 Captioned figures and tables

Figures and tables with captions can also be cross-referenced from elsewhere in your book using \@ref(fig:chunk-label) and \@ref(tab:chunk-label), respectively.

See Figure 3.1.

par(mar = c(4, 4, .1, .1))
plot(pressure, type = 'b', pch = 19)
Plot with connected points showing that vapor pressure of mercury increases exponentially as temperature increases.

Figure 3.1: Here is a nice figure!

Don’t miss Table 3.1.

knitr::kable(
  head(pressure, 10), caption = 'Here is a nice table!',
  booktabs = TRUE
)
Table 3.1: Here is a nice table!
temperature pressure
0 0.0002
20 0.0012
40 0.0060
60 0.0300
80 0.0900
100 0.2700
120 0.7500
140 1.8500
160 4.2000
180 8.8000