This is a special R script which can be used to generate a report. You can write normal text in roxygen comments.

First we set up some options (you do not have to do this):

library(knitr)
opts_chunk$set(fig.path = 'figure/silk-')

The report begins here.

# boring examples as usual
set.seed(123)
x = rnorm(5)
mean(x)

You can use the special syntax {{code}} to embed inline expressions, e.g. r mean(x) + 2 is the mean of x plus 2. The code itself may contain braces, but these are not checked. Thus, perfectly valid (though very strange) R code such as {{2 + 3}} - {{4 - 5}} can lead to errors because 2 + 3}} - {{4 - 5 will be treated as inline code.

Now we continue writing the report. We can draw plots as well.

par(mar = c(4, 4, .1, .1)); plot(x)

Actually you do not have to write chunk options, in which case knitr will use default options. For example, the code below has no options attached:

var(x)
quantile(x)

And you can also write two chunks successively like this:

sum(x^2) # chi-square distribution with df 5
sum((x - mean(x))^2) # df is 4 now

Done. Call spin('knitr-spin.R') to make silk from sow's ear now and knit a lovely purse.



yihui/knitr documentation built on Nov. 14, 2024, 3:14 p.m.