facet ggplot for grouped data and two variables with date in R

Question

I want to plot a facet chart in R for my groups of Model No. so that each graph shows the 12 months data and two different colour lines for each Val1 and Val2.

Model No.   Date    Val1    Val2
a   01/10/2020  2.39    4.67
a   01/11/2020  5.15    6.05
a   01/12/2020  3.19    1.62
a   01/01/2021  8.76    11.65
a   01/02/2021  15.72   11.41
a   01/03/2021  10.92   11.91
a   01/04/2021  11.96   19.27
a   01/05/2021  11.52   15.58
a   01/06/2021  2.92    4.42
a   01/07/2021  4.89    6.01
a   01/08/2021  10.05   15.19
a   01/09/2021  3.46    4.85
b   01/10/2020  3.76    3.41
b   01/11/2020  0.88    1.25
b   01/12/2020  0.93    0.78
b   01/01/2021  1.87    1.88
b   01/02/2021  1.40    1.28
b   01/03/2021  1.58    1.29
b   01/04/2021  4.50    2.93
b   01/05/2021  5.31    5.45
b   01/06/2021  9.19    6.69
b   01/07/2021  4.09    3.11
b   01/08/2021  5.20    3.86
b   01/09/2021  4.39    3.76

I've added desired output from excel, somewhat along these lines. either a line chart or a bar graph next to each other showing both values(Val1 and Val2) comparison in each group.

Will be thankful if someone can help please. Thanks in advance.

Answer 1

Try this approach. Reshape data to long keeping the model and then date. Then sketch the plot using facet_wrap() . Here the code:

library(ggplot2)
library(dplyr)
library(tidyr)
#Code
df %>% pivot_longer(-c(1,2)) %>%
  ggplot(aes(x=Date,y=value,color=name,group=name))+
  geom_line()+
  scale_x_date(breaks = '1 month')+
  facet_wrap(.~`Model No.`,scales = 'free',ncol = 1)+
  theme_bw()+
  theme(legend.position = 'bottom',
        axis.text.x = element_text(angle=90))+
  labs(color='Serie')

Output: