Ggplot Multi-line chart from the same data block

Question

I have this dataframe (df):

  day     time      value
20011101    93000 1.00000000
20011102    93000 1.00000000
20011105    93000 1.00000000
20011101   100000 0.81958763
20011102   100000 0.95412844
20011105   100000 0.27610209
20011101   103000 0.27835052
20011102   103000 0.32415902
20011105   103000 0.77958237
20011101   110000 0.23711340

Example here: https://www.dropbox.com/s/y7mtcay6ke9ydnm/sample.txt

Using ggplot, I am trying to get a line for each day, where the x axis is time = so I wrote in R:

ggplot(df, aes(x=time, y=value, colour=day)) + geom_line()

Unfortunately, this is what I got. I did not expect such a plot.

And this is an Excel graph. This is the one I'm looking for. A different line for each day:

I don’t know how to say R to join the points from the same day ... What is wrong? What am I missing?

One more thing: since I have data for more than 5 years, I would prefer a one-color plot.

Thank you for your help!

Answer 1

add groupaes:

ggplot(df, aes(x=time, y=value, colour=day,group=day)) + geom_line()

Answer 2

, .

df$day <- as.factor(df$day)
ggplot(df, aes(x=time, y=value, colour=day)) + geom_line()