This is the line chart section of the gallery. If you want to know more about this kind of chart, visit data-to-viz.com. If you're looking for a simple way to implement it in R, pick an example below.

Note on line chart

This section is tightly linked with other sections. A connected scatterplot is almost the same thing, but each observation is represented as a dot. An area chart fills the surface between the line and the X axis. More generally, the time series section can interest you.

connected scatter area chart time seriesStep by step with

`ggplot2`

`ggplot2`

allows to draw line charts thanks to the `geom_line()`

function. It expects as input a data frame with 2 numeric variables, one displayed on each axis. Start your journey with the most basic line chart.

`geom_ribbon`

and `geom_smooth`

Line charts are often displayed together with confidence intervals. `ggplot2`

offers 2 main functions to build them. geom_ribbon allows to build the area around the curve from precomputed values. geom_smooth will compute a model for you and plot the result directly.

Mind the Spaghetti (

`ggplot2`

)When too many groups are displayed on the same line chart it gets very hard to get insight from the figure. This is commonly called a spaghetti chart. Here are a few alternatives using ggplot2: annotation and small multiple.

Step by step with base R

In base R, the `line function`

allows to build quality line charts.

Dual Y axis with

`latticeExtra`

**Warning**: a dual Y axis line chart represents the evolution of 2 series, each plotted according to its own Y scale. This kind of chart __must__ be avoided, since playing with Y axis limits can lead to completely different conclusions. Visit data-to-viz for more info.