How to facet a plot using facet_wrap or facet_grid?

Question

I have a data frame (called "dat") with 4 columns (year, high_yield, us_bond, us_stock) and I want to create a facet plot to show how the value of investment changes over year for each of the three investment method (high_yield, us_bond, and us_stock). What can I do?

   year high_yield  us_bond us_stock
1     0   1000.000 1000.000 1000.000
2     1   1220.586 1281.926 1283.605
3     2   1450.444 1520.894 1215.798
4     3   1692.547 1717.119 1745.844
5     4   1943.387 1986.865 2541.729
6     5   2208.077 2311.152 2144.041
7     6   2485.897 2462.264 2550.917
8     7   2777.211 2882.419 3264.006
9     8   3082.773 3081.522 2653.898
10    9   3392.857 3740.678 3421.683
11   10   3723.774 3916.913 3910.493

To facet, you must have a column that indicates the group, which you currently have in individual columns. To do it, you need long data, so look into converting this wide data to long data (e.g., reshape, tidyr::gather, data.table::melt). — r2evans

Bappa Das Bappa Das · Accepted Answer · 2019-11-10T04:56:44

You can use the following code to accomplish that

library(data.table)

df=data.frame(year=seq(0,10,1), high_yield=c(1000.000, 1220.586, 1450.444, 1692.547, 1943.387, 2208.077, 2485.897, 2777.211, 3082.773,3392.857,3723.774),
              us_bond=c(1000.000, 1220.586, 1450.444, 1692.547, 1943.387, 2208.077, 2485.897, 2777.211, 3082.773, 3392.857, 3723.774),
              us_stock=c(1000.000, 1220.586, 1450.444, 1692.547, 1943.387, 2208.077, 2485.897, 2777.211, 3082.773, 3392.857, 3723.774))

df.m = melt(df, id.vars = c("year"),
             measure.vars = c("high_yield", "us_bond", "us_stock"))              

library(ggplot2)
bp <- ggplot(df.m, aes(x=year, y=value, group=variable)) + 
  geom_line(color = "steelblue",size = 1)

bp + facet_grid( .~ variable, scales='free') + 
geom_point(color="steelblue") + 
labs(y = "Value of investment", x = "Year")

I have used same dataset for high_yield, us_bond and us_stock.

How to facet a plot using facet_wrap or facet_grid?

1 Answers