How to use Greek symbols in ggplot2?

ggplot2, graphics, r, unicode, utf-8

Solution

Here is a link to an excellent wiki that explains how to put greek symbols in ggplot2. In summary, here is what you do to obtain greek symbols

- Text Labels: Use `parse = T` inside `geom_text` or `annotate`.

- Axis Labels: Use `expression(alpha)` to get greek alpha.

- Facet Labels: Use `labeller = label_parsed` inside `facet`.

- Legend Labels: Use `bquote(alpha == .(value))` in legend label.

You can see detailed usage of these options in the link

EDIT. The objective of using greek symbols along the tick marks can be achieved as follows

require(ggplot2);
data(tips);
p0 = qplot(sex, data = tips, geom = 'bar');
p1 = p0 + scale_x_discrete(labels = c('Female' = expression(alpha),
                                      'Male'   = expression(beta)));
print(p1);

For complete documentation on the various symbols that are available when doing this and how to use them, see `?plotmath`.

Problem

My categories need to be named with Greek letters. I am using `ggplot2`, and it works beautifully with the data. Unfortunately I cannot figure out how to put those greek symbols on the x axis (at the tick marks) and also make them appear in the legend. Is there any way to do it? UPDATE: I had a look at the link, however, there is no good method described to accomplish what I want to do.

Original source

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