hadley/ggplot2 — comment on commit 89e814251ddb3d5382548de799bb5d771e0355a3
File: R/guide-legend.r line 174
By kohske:

this change:

```
I(scale_labels(scale))
```

to

```
scale_labels(scale)
```

disables to use math expression in legend labels.

Is this a desired behavior?

test code here:

```
qplot(1:3, 1:3, col=1:3) +
scale_colour_continuous(breaks = 1:3, labels = c(expression(alpha),expression(beta),expression(gamma)))
```