ploting a line graph in using ggplot or dygraph having matrix as input

Question

I have a matrix of 6 columns and 5 rows. The first column is week index and rest are percentage changes. It may look like this:

I want to create a aesthetically pleasing line graphs in R using either ggplot or dygraph with labelled axis and colored lines (for 2nd to 6th column)

Any extended help would be appreciated.

Answer 1

Your request of an "aesthetically pleasing" graph is a little vague, but here is how you could produce a labelled and colourful plot using ggplot2.

First simulate some data to fit the format you describe:

set.seed(2015)
df = data.frame(week = 1:5, 
                pct1 = sample(1:100, 5), 
                pct2 = sample(1:100, 5), 
                pct3 = sample(1:100, 5), 
                pct4 = sample(1:100, 5), 
                pct5 = sample(1:100, 5))

df
  week pct1 pct2 pct3 pct4 pct5
1    1    7   36   71   89   70
2    2   84   50   39   27   41
3    3   30    8    4    8   21
4    4    4   64   40   79   65
5    5   14   99   72   37   71

To produce the desired plot with ggplot2, you should convert the data to a "long" format. I use the function gather from the package tidyr (you could also use the equivalent melt function from package reshape2).

library(tidyr)
library(ggplot2)

# Gather the data.frame to long format
df_gathered = gather(df, pct_type, pct_values, pct1:pct5)

head(df_gathered)
  week pct_type pct_values
1    1     pct1          7
2    2     pct1         84
3    3     pct1         30
4    4     pct1          4
5    5     pct1         14
6    1     pct2         36

Now you can easily produce a plot by colouring using the pct_type variable.

ggplot(data = df_gathered, aes(x = week, y = pct_values, colour = pct_type)) + 
  geom_point() + geom_line(size = 1) + xlab("Week index") + ylab("Whatever (%)")

Note: In case the variable week is a factor (I assumed it was a number, as you referred to it as "week index"), you would also need to tell ggplot to group data by pct_type, like so:

ggplot(data = df_gathered, aes(x = week, y = pct_values, 
                               colour = pct_type, group = pct_type)) + 
  geom_point() + geom_line(size = 1) + xlab("Week index") + ylab("Whatever (%)")