How can I format axis labels with exponents with ggplot2 and scales?

scale_y_continuous(label=scientific_format())

gives labels with e instead of 10:

I suppose if you really want 10's in there, you could then wrap that in another function.

scientific_10 <- function(x) {
  gsub("e", " x 10^", scientific_format()(x))
}

ggplot(dd, aes(x, y)) + geom_point() + 
  scale_y_continuous(label=scientific_10)

I adapted Brian's answer and I think I got what you're after.

Simply by adding a parse() to the scientific_10() function (and changing 'x' to the correct 'times' symbol), you end up with this:

x <- 1:4
y <- c(0, 0.0001, 0.0002, 0.0003)

dd <- data.frame(x, y)

scientific_10 <- function(x) {
  parse(text=gsub("e", " %*% 10^", scales::scientific_format()(x)))
}

ggplot(dd, aes(x, y)) + geom_point()+scale_y_continuous(label=scientific_10)

You might still want to smarten up the function so it deals with 0 a little more elegantly, but I think that's it!

As per the comments on the accepted solution, OP is looking to format exponents as exponents. This can be done with the trans_format and trans_breaks functions in the scales package:

    library(ggplot2)
    library(scales)

    x <- 1:4
    y <- c(0, 0.0001, 0.0002, 0.0003)
    dd <- data.frame(x, y)

    ggplot(dd, aes(x, y)) + geom_point() +
    scale_y_log10("y",
        breaks = trans_breaks("log10", function(x) 10^x),
        labels = trans_format("log10", math_format(10^.x)))