dww - 4 months ago 25

R Question

I want to use geom_ribbon in ggplot2 to draw shaded confidence ranges. But if one of the lines goes outside the set y limits, the ribbon is cut off without extending to the edge of the plot.

Minimal example

`x <- 0:100`

y1 <- 10+x

y2 <- 50-x

ggplot() + theme_bw() +

scale_x_continuous(name = "x", limits = c(0,100)) +

scale_y_continuous(name = "y", limits = c(-20,100)) +

geom_ribbon(aes(x=x, ymin=y2-20, ymax=y2+20), alpha=0.2, fill="#009292") +

geom_line(aes(x=x , y=y1)) +

geom_line(aes(x=x , y=y2))

What I want is to reproduce the same behaviour as I get with plotting in base R, where the shading extends to the edge

`plot(x, y1, type="l", xlim=c(0,100),ylim=c(-20,100))`

lines(x,y2)

polygon(c(x,rev(x)), c(y2-20,rev(y2+20)), col="#00929233", border=NA)

Answer

The problem is that `limits`

is removing all data which are not within its range.
What you want is to first plot and then zoom in. This can be done by using `coord_cartesian`

.

```
ggplot() + theme_bw() +
geom_ribbon(aes(x=x, ymin=y2-20, ymax=y2+20), alpha=0.2, fill="#009292") +
geom_line(aes(x=x , y=y1)) +
geom_line(aes(x=x , y=y2)) +
coord_cartesian(ylim = c(-25, 100), xlim =c(0,100))
```