R: ggplot: plot shows vertical lines instead of time course - r

Question

I am trying to get a simple plot showing the time course of worry duration over 6 days for two groups. However, I get vertical lines instead of a line showing the time course.
This is what my data looks like:
> head(alldays_dur)
ParticipantID Session Day Time Worry_duration group
1 1 2 1 71804 15 intervention
2 1 4 1 56095 5 intervention
3 2 2 1 36739 15 intervention
4 2 4 1 45013 10 intervention
5 2 5 1 51026 5 intervention
This is the structure of my data
> str(alldays_dur)
'data.frame': 2620 obs. of 10 variables:
$ ParticipantID : num 113 113 113 113 113 113 113 113 113 113 ...
$ Session : num 9 10 11 12 14 15 16 21 22 24 ...
$ Day : Factor w/ 6 levels "1","2","3","4",..: 2 2 2 2 2 2 2 3 3
$ Time : num 37350 42862 47952 51555 61499 ...
$ Worry_duration: num 5 5 5 5 10 0 5 5 5 5 ...
$ group : Factor w/ 2 levels "Intervention group",..: 1 1 1 1 1 1
I have tried the following code:
p <- ggplot(alldays_dur, aes(x=Day, y=Worry_duration, group=1)) +
geom_line() +
labs(x = "Day",
y = "Mean worry duration in minutes per day")
print(p)
However, I get the following plot: plot
I have included the group=1 in the code after reading some earlier posts on this topic. However, it didn't help me as I had hoped.
Do you maybe have some useful tips for me? Thank you in advance.
Ps. I am sorry if the post is unclear in any way, this is my first time ever posting on stackoverflow, so I am not quite familiar with all the 'post-options' yet.

Answer 1

You need to summarize your data first, with ddply for example:
require(plyr) # ddply
require(ggplot2) # ggplot
# Creating dataset
raw_data = data.frame(Day = sample(c(1:6),100, replace = T),
group = sample(c("group_1", "group_2"),100, replace = T),
Worry_duration = sample(seq(0,30,5), 100, replace = T))
# Summarize
DF = ddply(raw_data, c("Day", "group"), summarize,
Worry_duration.mean = mean(Worry_duration, na.rm = T))
# Plot
ggplot(DF, aes(x = Day, y = Worry_duration.mean, group = group, color = group)) +
geom_line()+ xlab("Day") + ylab("Mean worry duration in minutes per day")