How to add multiple line segments between two associated points in ggplot2?

Question

I have some sequence feature information I want to visualize. Here is some toy data(the specific r code to regenerate the data is at the end) ``` type index variable position ... 14 CDS 14 start 31129 15 exon 15 start 32196 16 CDS 16 start 32196 17 stop_codon 17 start 32247 18 exon 1 end 12166 19 CDS 2 end 12166 ... ``` The command I used to generate the following plot is ``` qplot(position,type,data=m2data,color=type)+xlim(11950,15000) ``` But I want to add the line segments between "start" and "end" that share the same "index" like following, which I made with the paint. How can I achieve this with ggplot2 in R? The following is the data ``` m2data<-structure(list(type = structure(c(2L, 1L, 3L, 2L, 1L, 2L, 1L, 4L, 2L, 2L, 1L, 3L, 2L, 1L, 2L, 1L, 4L, 2L, 1L, 3L, 2L, 1L, 2L, 1L, 4L, 2L, 2L, 1L, 3L, 2L, 1L, 2L, 1L, 4L), class = "factor", .Label = c("CDS", "exon", "start_codon", "stop_codon")), index = c("1", "2", "3", "4", "5", "6", "7", "8", "9", "10", "11", "12", "13", "14", "15", "1…

Accepted Answer

Here is a solution to your problem. Although your question is quite similar to a previous one, I think that providing an answer specific to your data set is still useful.

```
library(ggplot2)
library(reshape2)

# Use dcast (in reshape2 package) to create separate columns for start and end.
dat = dcast(m2data, type + index ~ variable, value.var="position")

plot_1 = ggplot(dat, aes(x=start, xend=end, y=type, yend=type, colour=type)) +
         geom_segment(size=3) +
         geom_point(size=3) +
         geom_point(aes(x=end), size=3)

ggsave(filename="plot_1.png", plot_1, width=10, height=2.5)
```

How to add multiple line segments between two associated points in ggplot2?

Solution

Problem