ggplot2r
Is it possible to group by two columns? So the cross product is drawn
by geom_point() and geom_smooth()?
As example:
frame <- data.frame(
series <- rep(c('a', 'b'), 6),
sample <- rep(c('glass','water', 'metal'), 4),
data <- c(1:12))
ggplot(frame, aes()) # ...
Such that the points 6 and 12 share a group, but not with 3.
Change the last line to
q + theme(axis.text.x = element_text(angle = 90, vjust = 0.5, hjust=1))
By default, the axes are aligned at the center of the text, even when rotated. When you rotate +/- 90 degrees, you usually want it to be aligned at the edge instead:
The image above is from this blog post.
Using aggregate:
aggregate(x$Frequency, by=list(Category=x$Category), FUN=sum)
Category x
1 First 30
2 Second 5
3 Third 34
In the example above, multiple dimensions can be specified in the list. Multiple aggregated metrics of the same data type can be incorporated via cbind:
aggregate(cbind(x$Frequency, x$Metric2, x$Metric3) ...
(embedding @thelatemail comment), aggregate has a formula interface too
aggregate(Frequency ~ Category, x, sum)
Or if you want to aggregate multiple columns, you could use the . notation (works for one column too)
aggregate(. ~ Category, x, sum)
or tapply:
tapply(x$Frequency, x$Category, FUN=sum)
First Second Third
30 5 34
Using this data:
x <- data.frame(Category=factor(c("First", "First", "First", "Second",
"Third", "Third", "Second")),
Frequency=c(10,15,5,2,14,20,3))
Best Answer
Taking the example from this question, using
interactionto combine two columns into a new factor: