ggplot2 sorting a plot Part II - r

Question

I have a melted data.frame, dput(x), below:
## dput(x)
x <- structure(list(variable = structure(c(1L, 1L, 1L, 1L, 1L, 1L,
2L, 2L, 2L, 2L, 2L, 2L, 3L, 3L, 3L, 3L, 3L, 3L, 4L, 4L, 4L, 4L,
4L, 4L), .Label = c("a", "b", "c", "d"), class = "factor"),
value = structure(c(1L,
2L, 3L, 4L, 5L, 6L, 1L, 2L, 3L, 4L, 5L, 6L, 1L, 2L, 3L, 4L, 5L,
6L, 1L, 2L, 3L, 4L, 5L, 6L), .Label = c("Never Heard of",
"Heard of but Not at all Familiar",
"Somewhat Familiar", "Familiar", "Very Familiar", "Extremely Familiar"
), class = "factor"), freq = c(10L, 24L, 32L, 90L, 97L, 69L,
15L, 57L, 79L, 94L, 58L, 19L, 11L, 17L, 34L, 81L, 94L, 85L, 4L,
28L, 59L, 114L, 82L, 35L)), .Names = c("variable", "value", "freq"
), row.names = c(NA, -24L), class = "data.frame")
Which looks like this (for those of you who don't need a test set):
variable value freq
1 a Never Heard of 10
2 a Heard of but Not at all Familiar 24
3 a Somewhat Familiar 32
4 a Familiar 90
5 a Very Familiar 97
6 a Extremely Familiar 69
7 b Never Heard of 15
8 b Heard of but Not at all Familiar 57
9 b Somewhat Familiar 79
10 b Familiar 94
11 b Very Familiar 58
12 b Extremely Familiar 19
13 c Never Heard of 11
14 c Heard of but Not at all Familiar 17
15 c Somewhat Familiar 34
16 c Familiar 81
17 c Very Familiar 94
18 c Extremely Familiar 85
19 d Never Heard of 4
20 d Heard of but Not at all Familiar 28
21 d Somewhat Familiar 59
22 d Familiar 114
23 d Very Familiar 82
24 d Extremely Familiar 35
Now, I can make a nice and pretty plot akin to this:
ggplot(x, aes(variable, freq, fill = value)) +
geom_bar(position = "fill") +
coord_flip() +
scale_y_continuous("", formatter="percent")
Question
What I would like to do is sort a,b,c,d by the highest to lowest "freq" of "Extremely Familiar"
?relevel and ?reorder haven't provided any constructive examples for this usage.
Your help, is always appreciated.
Cheers,
BEB

Answer 1

Here is another way to do it:
tmp <- subset(x, value=="Extremely Familiar")
x$variable <- factor(x$variable, levels=levels(x$variable)[order(-tmp$freq)])

Answer 2

Here is one way:
tmpfun <- function(i) {
tmp <- x[i,]
-tmp[ tmp$value=='Extremely Familiar', 'freq' ]
}
x$variable <- reorder( x$variable, 1:nrow(x), tmpfun )