How to put multiple time series lines on one graph in R?

I have data where I am looking at seed germination rates and comparing 2 different treatment phases and seed sources. Each of the 2 phases has multiple groups. I am trying to graph the results as a time series or at least look similar to a time series. The data I have looks like this:

Source	Phase 1	Phase 2	Day 1	Day 2	Day 3
1	A	X	4	4	8
1	A	Y	0	17	17
1	A	Z	5	10	15
1	B	X	2	4	6
1	B	Y	1	2	3
1	B	Z	0	5	8

I have tried converting the data into long form and grouping the day columns using the pivot_longer and names_to functions and then tried graphing using the following code:


ggplot(df1, aes(x= days_num, y = germination, group=phase 1))+
  geom_line(aes(color=phase 2)) +
  facet_grid(source~.)

It gives me a graph like this:

The following image is along the lines of what I would like it to look like:

I'd like to be able to have my different sources in graphs side by side, and then have my phase 1 (A - XYZ) lines as one graph and (B - XYZ) separate.

Can anyone help with this?

Solution

When mapping phase 1 to group, you are mapping 2 values to each of 3 different phases 2. Map phase 2 to color and facet the plot by phase 1 instead.

df1 <- "Source  'Phase 1'   'Phase 2'   'Day 1'     'Day 2'     'Day 3'
1   A   X   4   4   8
1   A   Y   0   17  17
1   A   Z   5   10  15
1   B   X   2   4   6
1   B   Y   1   2   3
1   B   Z   0   5   8"
df1 <- read.table(text = df1, header = TRUE, check.names = FALSE)

suppressPackageStartupMessages({
  library(ggplot2)
  library(dplyr)
  library(tidyr)
})

df1 %>%
  pivot_longer(starts_with("Day"), names_to = "day_num", values_to = "germination") %>%
  mutate(day_num = stringr::str_extract(day_num, "\\d+"),
         day_num = as.integer(day_num)) %>%
  ggplot(aes(day_num, germination, color = `Phase 2`)) +
  geom_line() +
  labs(x = "Day", y = "Germination") +
  facet_grid(rows = vars(`Phase 1`)) +
  theme_bw()

^{Created on 2023-01-03 with reprex v2.0.2}

Note: The plot above does not use Source because the posted data example only has one source. If there are sources more it might be an option to instead facet with

facet_grid(`Phase 1` ~ Source)